Veterinary Nursing of Exotic Species Lectures: Rabbits, Birds & Rodents

Hi all,

I have been asked back to lecture again this year by The College of Animal Welfare at Potter’s Bar, so will be running three days of lectures for veterinary nurses who are interested in caring for exotic pets. ‘Exotics’ in veterinary medicine as you’ll know covers any pet that isn’t a dog or cat, so we will be kicking off on 11th May with Rabbits, then 3rd June with nursing care of Birds and on the 19th October Small Furries aka rodents and other small mammals. Please share if you know of any veterinary nurses who are interested in improving their knowledge and practical skills with exotic pets. I promise they will be fun and useful sessions to build your confidence with these animals, and you’ll bring back lots of tips & tricks to use in practice!

Here’s the link to where you can book a place (, and some more details in the meantime:

Veterinary Nursing CPD and Events – Nursing the Rabbit Patient
Wed 11th May 9:30-16:00, CAW Potters Bar, EN6 1NB
Rabbits are the 3rd most popular pet in the UK. This course is aimed at students and qualified veterinary nurses who wish to expand and update their knowledge of the pet rabbit – you’ll be seeing them at least weekly!
The day will recap handling techniques (theory only), husbandry, aspects of nutrition, common illnesses and anaesthesia within a referral practice setting.
Sean McCormack is a qualified veterinary surgeon with extensive experience in exotic medicine, and has lectured and written about exotic medicine many times.Lecturer: Sean McCormack BSc (Hons), MVB, MRCVS


Veterinary Nursing CPD and Events – Nursing the Bird Patient

Fri 3rd Jun 9:30-16:00, CAW Potters Bar, EN6 1NB
A wide variety of birds are frequently seen in clinical practice. Your patients can range from a timid little budgie all the way to an angry parrot with a razor sharp beak. Despite the varied background the initial treatment and supportive care of birds can be applied across many species. This day will cover the basic husbandry of commonly seen species and consider triage, as well as emergency treatment and supportive care of ill birds.
Sean McCormack is a qualified veterinary surgeon with extensive experience in exotic medicine, and has lectured and written frequently on exotic medicine issues.Lecturer: Sean McCormack BSc (Hons), MVB, MRCVS


Veterinary Nursing CPD and Events – Nursing the Common Small Furry

Wed 19th Oct 9:30-16:00, CAW Potters Bar, EN6 1NB
‘Small furries’ are popular pets, this course is aimed at students and qualified veterinary nurses who wish to expand and update their knowledge of the more common small furry animals. The day will recap handling techniques (theory only), husbandry, aspects of nutrition, common illnesses and anaesthesia within a first opinion practice setting.
Sean McCormack is a qualified veterinary surgeon with extensive experience in exotic medicine, and has lectured and written about exotic medicine many times.Lecturer: Sean McCormack BSc (Hons), MVB, MRCVS




Respiratory Conditions in Reptiles


Respiratory diseases in captive reptiles are all too common unfortunately and are a great source of frustration for owners and vets alike, as well as being a serious welfare concern for the animals affected. There are many causes including parasitic, bacterial, viral and fungal infections as well as traumatic injury, tumours and cardiac disease. Reptile respiratory disease is often more severe and difficult to treat than in mammals due to differences in anatomy and physiology, outlined below. As a vet with a special interest in reptiles, I often look at online herpetological forums. Treatment of respiratory infections, or R.I’s, is one of the most frequent topics provoking debate and disagreements, prompting criticism of vets as well as hobbyists, and often resulting in potentially harmful or at least misleading information being spread by so called experts. I am writing this article to provide an overview on respiratory conditions and treatments in reptiles. Hopefully this will give a better understanding of how such conditions can be prevented, what to look for when they do occur, how they can be treated and why they can be so difficult to treat. I will also attempt to dispel any misconceptions and answer some of the most common questions I encounter in clinical practice as well as on hobbyist forums. Similarly I will try to explain the decision making process and give an insight from the vet’s side of the consult table as I do see this as an area where the vet-client relationship is frequently strained due to poor communication on both sides.

By far the best advice I can give as a vet is in prevention of respiratory disease through various husbandry and biosecurity measures. I would also like to highlight why specific advice given by experienced reptile veterinarians is so important in the outcome of the case. I have often been disappointed and disheartened in practice when treating an R.I. case when the owner doesn’t follow the directions given or take my husbandry advice on board, and is then disappointed when the treatment fails or they can no longer afford treatment and the animal ends up severely debilitated, has to be euthanised or dies. I have had my work and reputation criticised to colleagues and undoubtedly on forums when “the antibiotics he dispensed didn’t work”. These were invariably in cases where the owner didn’t follow all the other suggestions that go along with medication, when they brought the animal to me in an advanced state of disease and were informed of a guarded prognosis but decided to try treatment anyway or where they didn’t return for me to establish why my treatment of choice didn’t work. I will get the defensive vet disclaimer out of the way now at the start of the article. Treating R.I’s in reptiles is not just about dispensing antibiotics, or about which antibiotic is dispensed. Enough with the Baytril bashing! Successful outcomes rely on a holistic, integrated approach as well as the hobbyist working with the vet, not against. Believe it or not, and I can’t speak for every vet, our main concern is that your animal gets better and we have a happy client at the end of our interaction. With that said, let’s get on with our discussion…

Anatomy & Physiology:

The difficulty in treating respiratory disease in reptiles is primarily due to their inability to effectively clear fluid, debris and discharges from their airway by coughing. Most species, apart from crocodilians, lack a true diaphragm and therefore do not possess a cough reflex. The mucociliary escalator apparatus is poorly developed in the reptile airway also, which complicates clearance of infectious agents and subsequent secretions. The mucociliary escalator is an adaptation of mammals which allows any inhaled debris, micro-organisms or secretions to be transported up the airway and trachea (windpipe) by mucus and tiny microscopic hairlike projections, clearing them from the airway and allowing them to be swallowed into the hostile acid environment of the stomach. This is a vital defence against respiratory infection and disease which is lacking in reptiles when compared to mammalian species.
Secretions and infectious material therefore pool in the lower parts of the lungs making penetration by immune cells as well as medications very difficult, leading to chronic disease which is often difficult to treat. So having the same expectations for treatment of a respiratory infection in a snake or lizard for example compared to a dog or cat may result in disappointment. The anatomy of the reptile respiratory tract is also unique in several ways which can affect disease progression. The main anatomical feature of significance in reptiles is in snakes, most of which only have a single right lung. Lizards and chelonians have two symmetrical lungs. Boas and Pythons have a main single right lung and a much reduced or vestigial left lung. Some snakes also have a ‘tracheal lung’ which is an outpouching of the trachea with respiratory mucosa for gas exchange. Because of the single lung, snakes with respiratory infections are therefore even more challenging clinical cases than chelonians and lizards.



Poor husbandry is the single most important factor predisposing captive reptiles to disease, respiratory or otherwise. It should not be necessary to mention that the specific and exact needs of the individual species kept need to be researched and met accurately in order to preserve health and prevent health problems. Respiratory infections (R.I.’s) in particular, although caused by a variety of different pathogens, can almost always be traced back to an incorrect or inadequate husbandry issue, most notably related to temperature and humidity. It is therefore of the utmost importance that all reptiles are provided with perfect husbandry conditions that mimic as closely as possible their natural conditions and requirements in the wild. If any husbandry issues are sub optimal then the animal may succumb to an opportunistic infection through gradual debilitation and weakened immune defences. Nutritional deficiencies are a common factor leading to such debilitation and subsequent predisposition to infection. Hypovitaminosis A is important to mention as a lack of this vitamin frequently leads to disease or the oral and respiratory mucosa and therefore has a big impact on respiratory health. With this in mind let’s now discuss the various causes of respiratory illness.


Most common parasitic infections affecting the respiratory tract are caused by nematodes including Rhabdias spp. in snakes and Entomelas spp. in lizards.  These are specialised lungworms, although other nematodes can cause respiratory illness such as Kalicephalus spp., the snake hookworm which migrates through the body after entering via the skin or by ingestion, potentially causing severe tissue inflammation as it passes through tissues on its journey to the gut.  Similarly, ascarid worms frequently cause damage to lung tissue and the liver as they pass through the body as migrating larvae.  Apart from nematodes, the single-celled parasite Entamoebas invadens has been found to cause respiratory illness on occasion as well as some evidence of coccidiosis affecting the lungs in chelonia.  In amphibians, particularly wild caught specimens, the lungworm Cosmocercoides spp (see my image below from a White’s tree frog) can be found relatively frequently and is often fatal especially in captivity stressed or debilitated individuals (more information at:



Many bacterial pathogens have been isolated and implicated in lung disease in reptiles, some of which are primary pathogens and others are secondary invaders causing opportunistic infection. The presence of these micro-organisms does not necessarily indicate that disease is present, as they may be opportunistic only causing disease when the animal’s immune defences are weakened or defective.  Further pathogens may extend into the respiratory tract from other sites, most notably from generalised systemic infection or septicaemia, or from mouth infections (stomatitis).  The primary bacterial pathogens responsible for R.I.’s in reptiles most commonly are Aeromonas spp., Pseudomonas spp., Klebsiella spp., Salmonella spp.  and Pasteurella spp.  Bacterial infections may go hand in hand with viral infections, a common example being Mycoplasma or Mycobacteria present alongside Herpesvirus infection causing rhinitis or ‘Runny Nose Syndrome’ in tortoises.  Finally, Chlamydophila spp. has been implicated in some pneumonia in snakes.


Fungal R.I.’s are less common than bacterial or viral disease but do occur,  most frequently in chelonians such as tortoises.  The commonest infections result from exposure to saprophytic or soil fungi in the external environment and most are secondary pathogens to bacterial disease or traumatic injuries. If husbandry is inappropriate particularly with regard to ventilation and humidity the risk of fungal disease is often increased.  Notable species of fungi causing such infection are Aspergillus, Candida, Sporotrichum, Penicillium,  Paecilomyces and Cladosporum spp.


Several viral diseases are responsible for respiratory disease in reptiles including Paramyxovirus, IBD, Herpesvirus and Iridovirus.

Ophidian Paramyxovirus (oPMV)  is becoming increasingly common in captive snakes,  and has been occasionally reported in lizards,  though these are frequently asymptomatic when infected.  This virus is highly infectious causing haemorrhagic pneumonia and viraemia affecting other organ systems.  It is shed in respiratory secretions and can be easily spread through a collection by poor hygiene and sanitation practices.  Animals may lack clinical signs for long periods with the incubation phase lasting up to 8 weeks, so testing during this period can turn up false negative results for this reason.  Testing usually relies on post mortem sampling but blood serum analysis can be performed.  Another paramyxovirus related to the parainfluenza 2 virus (PI2) has been implicated in respiratory disease as well.

Inclusion Body Disease (IBD)  is a viral infection primarily of boas and pythons which can causes respiratory disease in the form of pneumonia, in addition to the more common central nervous signs such as ‘stargazing’ and gastrointestinal disease causing regurgitation and anorexia.  The exact viral agent responsible for IBD has long been debated and researched.  Thought to be a retrovirus scientists have only recently discovered that the infection is in fact caused by a new virus belonging to the Arenavirus group.

Herpesvirus is a common cause of respiratory disease in chelonians, particularly Mediterranean tortoises, often with devastating consequences. Such infections often cause secondary bacterial and mixed viral infections. Clinical signs include lethargy, rhinitis or ‘runny nose’, anorexia, conjunctivitis and stomatitis. This is a complex and extensive topic in itself, therefore I will endeavour to write a future article on the subject.

Finally, Iridoviral infections with Ranavirus in particular from amphibian hosts can cause severe necrotising tracheitis and pneumonia. This is an extremely aggressive infection causing extensive and painful tissue damage. Infections are extremely difficult to treat.


Trauma to the carapace of chelonians can lead to non infectious lung disease, often associated with attacks by dogs or wildlife, car accidents and even lawnmower injuries! Shell repair techniques are undertaken according to the individual injuries, but treatment of shock and secondary infections is vital in order for a successful outcome.

Cancer as in most species occurs more commonly in older animals, and is normally diagnosed by X-ray of the lower respiratory tract. Treatment is experimental as chemotherapy in reptiles is not widely used or researched.

Foreign Bodies: 

Inhaled foreign bodies are possible, but not common. Endoscopy is a useful tool for removal.

Cardiac Disease:  

Congestive heart failure and cardiomyopathies occasionally are seen, primarily in older or geriatric reptiles and can cause fluid congestion in the lungs leading to increased respiratory effort and subsequent lung disease. For an article on these conditions in two cases I saw in practice, visit

Clinical Signs:

Signs of disease are often very similar irrespective of cause, but can be extremely subtle particularly in the early stages of disease. The ability of reptiles to mask any signs of illness and the chronic nature of disease progression mean that by the time an owner notices the animal is unwell, the disease is already advanced. Again this has implications for successful treatment, so if in doubt or any of the following signs are observed, you should seek treatment immediately:

  • Dyspnoea (difficulty breathing) which can manifest as increased respiratory effort, extension of the neck or gulping for air
  • Tachypnoea (increased respiratory rate/rapid breathing)
  • Open mouth breathing
  • Yawning (particularly in snakes)
  • Nasal or oral discharges (appearance depends on cause; blocked nostrils may indicate previous discharge)
  • Ocular (eye) discharge
  • Respiratory noises (clicks, wheezes, ‘snuffles’)
  • Lethargy/depression
  • Anorexia/reduced appetite
  • Altered buoyancy in aquatic species
  • Dehydration
  • Postural changes (elevating head and neck vertically, particularly in snakes)
  • Altered thermoregulation (seeking cooler areas to hide, to alter metabolism and cope with hypoxia or diminished blood supply of oxygen)
  • Concurrent infections, specifically stomatitis or ‘mouth-rot’


Above: Abscess/stomatitis in a Royal Python.


Above: Chronic pneumonia, anorexia, emaciation, stomatitis in a Boa constrictor.


Diagnosis relies on a detailed history from the owner taking into account the original source of the animal in question, any husbandry issues that might predispose to certain conditions, the range of signs noticed, duration of the illness, species specific considerations, parasite control and nutritional status. Secondly a detailed physical exam will often give me far more information regarding the animal in question than an owner’s description over the phone or photos and descriptions online. A detailed clinical exam is one of the main diagnostic tools a vet has in assessing their patient, which unfortunately cannot communicate directly to us as in human medicine. Observing the animals breathing pattern and effort before handling gives a good idea of functionality and health of the respiratory tract. Examining the mouth and pharynx or throat region will often give clues such as inflammation or discharges from the airway, as well as highlighting stomatitis. Discharges can reveal a lot about the underlying pathogens present and sometimes may be sampled for microbiological examination and culture. Generally, cloudy or yellowish/green discharge indicates bacterial infection but can also be present in fungal or viral disease occasionally. Clear discharges are more classically viral indicators or a sign of mechanical irritation, and rarely seen in bacterial infections. Bloody or blood tinged discharge may indicate a more invasive infection, trauma or damage due to a foreign body in the airway. Similarly tumours of the respiratory tract may occasionally bleed and cause such discharge. Auscultation of the respiratory tract can be challenging in the reptilian patient as movement of rough scales against the diaphragm of the stethoscope can obscure respiratory sounds. Often I will use soaked cloth or cotton wool between the diaphragm and animal to create a better contact and decrease movement noise but this unfortunately also dampens respiratory noises.

As you can see many clues can be gleaned from a clinical examination. This is the reason I and many other vets are reluctant to make a diagnosis without seeing the animal. To do so would be negligent. So even if it sounds like a classic R.I. for example there may be vital signs that the owner relaying the information neglects to disclose, or more subtle signs that haven’t been noticed which alter the diagnosis or indeed prognosis of the case. I would be wary of giving out advice when in fact that advice could be useless or even dangerous to the animal in question. My prognosis may be optimistic if signs of a simple infection are described to me, but if the owner hasn’t noticed more serious signs in a pneumonia case for instance they will be extremely disappointed and doubt my knowledge if their snake dies soon after. Language is extremely important and vets are trained to describe illness in a very specific terminology, which may be completely meaningless to hobbyists. Because of this, one person’s description of a lesion or clinical signs of illness will differ significantly from another’s description. Many times I have had a long discussion with a reluctant owner on the phone to try and assess whether the animal needs to be brought to the vets in the first place, and having asked various questions have a definite picture in my head of the case that will present to me the following day. Quite often there are clues or details omitted or described differently and I am surprised by what is actually presented on the consult table. The point I am making is not to be offended or see my request to book an appointment as a waste of time or a money making exercise, when in fact it is merely that I cannot make a diagnosis or come up with the best possible treatment plan without physically examining the animal. Based on this examination and discussion I can then make recommendations and discuss options with the owner.

Once a good history and clinical exam is performed, some respiratory cases are reasonably simple to diagnose and a treatment plan can be made. This may involve a few subtle husbandry changes and dispensing a course of medications, antibiotics for example. I imagine many hobbyists who have experienced R.I’s in their pet reptiles have undergone a similar process at their vets. Very often this approach is satisfactory and a successful outcome is reached. But there are various pitfalls that may hinder such an outcome, and communication between the owner and vet as well as the knowledge and experience of the vet in question is vitally important at this stage. I will discuss the subtleties and decision making process on appropriate treatments later in this article. If the case is not a straightforward diagnosis based on history and physical examination then further tests may be required. These tests cost money, but are optional. Refusing these tests may alter the likelihood of success. As a vet it is my responsibility to offer them and explain their benefits. As a client it is your responsibility at the initial consult to discuss concerns about costs, ask for alternatives if available and ask questions of your vet as to the value of suggested diagnostics. If finances are limited, I would like to know this at the outset so I can come up with the best possible plan with the resources I have available.

In terms of diagnostics for respiratory disease, perhaps the most valuable is imaging by X-ray to visualise the lower respiratory tract, namely the trachea and lungs. The upper respiratory tract consists of fine bones of the nasal chambers and delicate structures in the throat, so is more difficult to interpret by X-ray but this can still give valuable information particularly where local inflammation, bone infections, tumours or foreign bodies are suspected. X-rays also allow the clinician to visualise the extent and location of disease which determines how aggressive the treatment required as well as allowing a better understanding of prognosis for success. In longstanding or advanced R.I.’s I am often met with reluctance or refusal to allow X-rays by the client, often for cost reasons. Despite warning that treating ‘blind’ may not yield successful results the client then gives informed consent to a ‘best guess’ treatment plan. It is extremely frustrating as a clinician if the case isn’t resolved, goes to another vet or dies at home resulting in an unhappy client, or an accusation of incompetence. I would urge all hobbyists to communicate and discuss their experiences with vet treatment, but to remember that especially on online forums people may omit their own role in deciding a treatment plan, and lay all the blame on the vet if it fails and they lose their animal. As you can appreciate as a vet I can offer best practice and work my way back according to the resources available, but I won’t advise doing a specific test unless I feel it will be advantageous in getting a successful outcome. X-rays are a classic example of a test that give the clinician valuable information to direct treatment appropriately, but can be difficult to convince an owner of any tangible benefit especially where finances are limited. Sometimes not doing a test sets the treatment up for failure from the very beginning.

Following X-rays, bloodwork and microbiological testing are also valuable tools in making a firm diagnosis and therefore choosing a successful treatment plan. In terms of bloodwork, haematology may reveal elevations in specific white blood cells relating to inflammation or active infection. In chronic cases however infection may be confined locally to lesions in the lungs for example and therefore white blood cell counts may be within normal limits. In such cases systemic treatment may be unnecessary and targeted treatments at the lesions of concern may be a more appropriate treatment option. Such targeted options include nebulisation of drugs into the airway directly, or surgical debridement and establishing access to lung abscesses to treat infected tissue directly. Biochemistry values may indicate that the animal in question has other metabolic problems or is heading towards liver or kidney failure due to advanced systemic infection for example. In such a case the value of doing blood tests first is obvious.

Where microbial sampling is concerned in the case of infectious disease there are two main techniques used, lung washes and direct sampling. Lung washes can provide useful information on what pathogen is involved in a specific infection, and subsequently by culturing these pathogens we can ascertain what antimicrobial drugs (e.g. antibiotics) are most effective to treat the infection present. However, it can be difficult to obtain a representative sample using this technique. Several times I have performed tracheal and lung washes in snakes in particular, introducing sterile saline into the airway and aspirating it back out again to sample the cells and potential pathogens causing illness, only to receive a report back from the laboratory stating that no micro-organisms were cultured even though bloods and clinical signs indicate an R.I. Similarly the sample may contain few if any cells when examined under the microscope, so this is a difficult technique and doesn’t always yield the desired results. The second approach is direct sampling of lesions in the lungs or lower airway by using a rigid endoscope or in the case of chelonians drilling a hole through the shell to gain access to the lungs in an advanced pneumonia case for example. If a valuable sample is obtained indicating an infectious agent, it is cultured in the lab and the pathogens causing infection can be identified and tested in order to determine what antibiotic medication would be most appropriate for treatment. In an ideal world, I would use culture and sensitivity for every infection I encounter in clinical practice, on exotic and companion animal cases. This approach is not practical, financially feasible for many clients or arguably necessary in the majority of presentations, as with experience and background knowledge most vets will know the common pathogens responsible for certain  conditions, and typically what classes of antibiotics are most suitable for treating such infections. There are always going to be resistant infections or atypical pathogens which require further investigation and possibly an alteration in treatment. So, as you can appreciate even with  owner consent to do diagnostics like culture and sensitivity testing in order to chose the right antibiotic for the infection present, the procedures in themselves can present a challenge to the most experienced clinician.

In many respiratory cases, and reptiles that are ‘generally unwell’ with vague signs of illness I will often ask for a faecal sample to screen for parasites, particularly where there is a history of a new animal, wild caught individual, a large collection with several cases of illness, lack of adequate quarantine or failure of initial treatment. As standard, I perform a direct faecal smear and a flotation test which will detect protozoal infections, pinworm, roundworm, tapeworm and lungworm eggs in the majority of cases. Lungworm infections are less common in captive reptiles than bacterial R.I’.s, at least in the UK where I practice but I would always bear them in mind if an assumed bacterial R.I. was unresponsive to best choice antibiotics. In wild caught animals, before I commence any treatment I insist on a faecal screen as they invariably harbour parasitic infection which may compromise an already stressed or debilitated reptile, if not cause the primary illness itself.

Endoscopy can be useful for visualising the airway and sampling especially in chelonians and lizards, but due to the elongated lung in snakes it is less useful. Specialised small rigid endoscopes are mostly required unless in very large reptile patients, and such equipment is very expensive so is not available at every vet clinic, exotic or otherwise.

Using the above diagnostic tools and techniques, a diagnosis can be reached in the majority of cases. However there will always be cases which do not typically present, or are less clear and can be a diagnostic challenge for even the most experienced clinician. Take it from me that these cases are just as frustrating to the vet as the owner. Please discuss your concerns with your vet if you do not understand any part of the treatment/diagnostic process, or if you have suggestions on how to improve treatment again you should talk to them. You are at any point welcome to seek a second opinion or ask for a referral appointment if you think your vet is not managing the case effectively or does not have enough knowledge or experience with the species in question. On a side note this is the reason I always recommend locating a trusted and recommended exotics/reptile veterinarian to treat your animals before the need arises in the first place.
Prevention and Treatment:

Husbandry is arguably the most important factor both in the incidence of respiratory disease in the first place as well as the outcome of clinical case management. An absolutely critical consideration is that the reptile is kept in its preferred optimal temperature zone (POTZ) at all times but even more crucially during treatment. It is pointless administering antibiotics or indeed other medications if the animal is housed incorrectly. Poor husbandry, specifically low temperatures or inappropriate humidity levels for the species in question are the critical factors that predispose to respiratory disease. The animal must have a temperature gradient to control its body temperature. Often reptiles with respiratory disease will seek out the cooler end of their enclosure to slow their metabolism and relieve the demands for oxygen placed on a compromised respiratory tract. This tendency can be counterproductive to successful treatment however in that a slow metabolism will also impair the immune system and the action of the medication will be reduced, so it is important that the coolest area of the vivarium is still well within the POTZ. The warmest end of the vivarium can actually be a little higher than usual but not too far outside the POTZ. Accurate control of heating with a reliable thermostat is vital to prevent overheating the vivarium. One of the common misconceptions relating to R.I’s in reptiles is that boosting the temperatures up high will often resolve the infection itself. Certainly in some instances where there is a low grade infection in a relatively healthy and robust animal this may help and contribute to the animal clearing the infection, but I would question whether the animal may have cleared such an infection of its own accord anyway despite bumping the temperatures up by a few degrees. My advice in such cases is firstly to accurately measure the temperatures in the enclosure, then accurately control the temperatures. These processes require investment of buying a reliable thermometer and thermostat if not already used, which are arguably essential kit in the first place. Many reptile owners presenting their very ill pet to me have no idea what temperature their vivarium is at different times of day or night, and in some cases no idea what temperature their animal needs to begin with, instead trusting that the equipment sold in the pet shop will produce the exact requirements needed for their pet.

In terms of heating equipment itself, the vital parameter for provision of an appropriate POTZ is ambient air temperature. For this reason and of course there are some species-specific exceptions, I prefer and advocate the use of heat lamps, bulbs or ceramic heaters as a primary heat source rather than heat mats. The first reason is that these provide a far more reliable temperature gradient in the ambient air temperature of the enclosure as opposed to a warm spot on the floor or wall of the vivarium provided by the heat mat. Perhaps more importantly, the use of heat mats encourages the animal to either sit on the mat itself if seeking warmth or avoid it entirely and chill to below its POTZ which does not help treatment, in terms of immune function or drug metabolism both of which are intrinsically temperature dependent. The other major problem with heat mat use as the primary heat source is that this system does not encourage the animal to move about its enclosure or maintain activity along a more natural ambient temperature gradient. The effect of providing belly heat only to an R.I. case is that respiratory secretions and infectious material accumulates to a greater extent in static animals sitting on belly heat than in those encouraged to move about more with the provision of adequate space, varied cage furnishings allowing movement in the horizontal and vertical planes as well as sufficient ambient heat to remain comfortable and regulate temperature throughout the entire enclosure as opposed to just in the immediate vicinity of a heat mat.

Thinking of these considerations, perhaps the worst possible husbandry system for R.I.’s in reptiles is the all too common trend of keeping snakes (single lung, poor clearance) in rack systems, with very little space to move (inhibits respiratory clearance), in close proximity to dozens or some cases hundreds of other animals (thus facilitating spread of infectious agents) and where they are not checked frequently enough or for a sufficient time to spot the early signs of infection in the first place. Many large scale hobbyists and breeders, private and commercial alike are the worst affected in terms of R.I.’s. This is no coincidence. As a herpetoculturist for many years myself, my belief was always that if we are to keep such animals we should strive to provide as natural a captive environment as possible for them to keep them healthy. The practice of keeping snakes in particular in tiny plastic tubs without appropriate light and often inadequate heating with no thermal gradient is about as far removed from natural as one can get. Perhaps controversially, I would suggest that if we want to keep and raise healthy animals we as responsible herpetoculturists need to redirect the hobby away from large scale reptile production of highly valuable, in some cases highly inbred genetic mutants kept in entirely inappropriate conditions to maintain long term health, the current royal python craze being a prime example. I appreciate this is idealistic as where there is money to be made economics dictate that minimum animal welfare standards are maintained. But just because everybody else is doing it or this system is now seen as standard doesn’t make it right. In short, if you provide adequate space and appropriate conditions for your few select reptile pets rather than substandard conditions for your large collection, it is likely you will avoid causing respiratory illness notwithstanding accidental introductions of infectious agents in new animals. Quarantine and biosecurity measures are vital in preventing infectious disease entering a collection in the first place, as well as spreading between animals from affected individuals.

For the reasons outlined above, part of my treatment plan involving a respiratory case will always involve a review of husbandry particulars for the patient in question. As a vet it is my responsibility to ask these questions and make suggestions on where I see problems. I’m sure some clients feel like I’m accusing them of making their reptile ill or not providing adequate conditions, but most are open to these suggestions and when I assure them that by making these changes the chance of success will be higher they most often do so. My intentions are purely to fill in the blanks if a client has misunderstood or is unaware of all the husbandry requirements for their pet. A very few clients have repeatedly ignored husbandry advice, for example to get their snake out of the RUB (really useful box; perhaps that should be RIB, respiratory infection box) and buy a heat lamp/thermostat in place of the heat mat. One really frustrating case I had was a chronic R.I, unresponsive to treatment and eventually resulted in having to euthanise a pneumonic cornsnake! Cornsnakes as you all know are hardy creatures. Husbandry in this case was poor. They couldn’t tell me the temperature of the vivarium on any of their multiple visits, despite asking repeatedly for this information. None of the owners would listen or accept that this infection may be husbandry related. On the third or fourth occasion they visited and again I asked if they had changed the housing and heating arrangements as recommended I was met with the angry reply that ‘someone on the forums said cornsnakes are fine on heat mats’. Again I explained that a healthy cornsnake may do fine, but an R.I cornsnake will not. It fell on deaf ears. They were very unhappy to return weeks later after missing their follow up appointment with a very poorly snake. The main reason they were unhappy was that my treatment didn’t work and they had ‘wasted all that money’ extending the antibiotics after each visit. Now they had no option but to give up and have the snake euthanised. I felt for them losing their pet, but even if I provided gold standard treatment for this snake for free, I could not convince them to change the snake’s conditions as they had read online what they were doing was perfectly adequate. So the snake was doomed from the start. I’m sure if asked they would have laid all the blame at my feet for their snake dying, and no doubt called me a dreadful vet. They may have even posted their version of events portraying me as such on their online forum of choice. The reason I relate this story is firstly to highlight the danger of believing everything you read online, regarding husbandry in general and treatment of medical conditions by non-medically trained professionals, but also in terms of vet reviews. There are two sides to the consult table. I hope you can appreciate my frustrations in such cases.

In terms of treatment, firstly I will touch briefly on choice of medication. I could write a whole chapter on the use of antibiotics but it is beyond the scope of this article. The medication dispensed is often blamed if the treatment is unsuccessful, hence my earlier comment on ‘Baytril bashing’. The aim of treating a simple R.I. as an example would be to choose an antibiotic that concentrates well in respiratory tissue, is broad spectrum meaning it is effective against a wide variety or organisms, has a well documented success rate in treating the most common infectious micro-organisms found in reptile R.I’s, has low incidence of resistance, has few side effects and is licensed for use in these species. Baytril, the generic name for the drug Enrofloxacin, ticks all of these boxes believe it or not. As such it is a perfectly good choice in first line antibiotic treatment for uncomplicated R.I’s in reptiles, with several exceptions and some specific considerations. This is why it is often used as a first line drug of choice for a wide variety of infectious conditions in reptiles. It is not necessarily because the vet in question doesn’t know what else to use, but moreso a licensing issue and the fact that it is a very useful antibiotic. I am not familiar with US laws and licensing, but in the UK Baytril is the only antibiotic licensed for use in most exotic species, and there are legal guidelines about using other drugs off-license where necessary. Again these issues are beyond the scope of the article, but because of this many vets will use Baytril as their first choice in reptiles, and change antibiotics later if ineffective. However, Baytril like any drug can be used irresponsibly or ineffectively.

Antibiotics that I frequently consider and use for treatment of R.I.’s in reptiles are the fluoroquinolones Enrofloxacin (Baytril) and Marbofloxacin (Marbocyl), the third generation cephalosporins Ceftazidime (Fortum), Ceftiofur (Excenel) and Cefotaxime (Claforan), the aminoglycoside antibiotic Amikacin (Amikin) and in certain circumstances the macrolides Azithromycin and Clarithromycin or tetracyclines such as Doxycycline. As you can appreciate there is a wide choice available each with it’s own indications and side effects, but unnecessary or inappropriate use of antibiotics can be just as harmful as choosing the wrong drug initially. Choice of antibiotic depends on culture/sensitivity results if available, safety, owner’s ability to administer such medications and often cost of treatment. There are many variables in the use of such medications which can result in success or failure of treatment. The common complaints I refer to reading about on message boards are often the ‘wrong antibiotic’ or that a vet should have been using a ‘stronger antibiotic’. The wrong antibiotic would be one which does not effectively treat the types of pathogens commonly causing the infection in question. A vet prescribing Baytril for a lizard or snake R.I. with poor results when another snake was prescribed Fortum for an R.I. and had great results does not necessarily constitute choosing the wrong antibiotic. To say so is entirely simplistic and doesn’t take into account a multitude of specific variables and the intricacies of the consult and decision making process outlined previously. Similarly, an antibiotic can only be described as ‘not strong enough’ if the vet has prescribed or owner administered an insufficient quantity of the antibiotic. One antibiotic class or drug is not stronger than other medications. They work in different ways and have different spectrum of activity against certain types of organisms. The strength of an antibiotic is dose related, and it is entirely possible that failure of a case may lie in the fact that a low dose was given which failed to overcome the infection. Hence my frustration when I read countless vet bashing threads about choosing the wrong antibiotic or it not being strong enough without any appreciation for other factors which may have influenced the case.

The duration of treatment is critical for example, so most R.I. cases would require at least 14-21 days of continuous treatment in my view. Very often I will prescribe antibiotics for 4-6 weeks in severe cases. If very mild signs I may reassess the animal after 7-10 days and review the treatment plan if appropriate. Dosage decisions need to reflect the individual animal in question and severity of disease versus a risk based assessment of side effects. A sound knowledge of pharmacology, pharmacokinetics and experience in treating similar cases is required in order to balance all of these variables and decide on the correct dosage and duration. I make a point of never communicating dosages for general treatment of conditions online, as all too often I find incorrect interpretations or ‘one fits all’ advice on how to use medications by so called experts. Applying such an approach to treatment of complicated disease processes that vary in many ways between species and individual cases is destined for failure. The route of medication is also important and can influence outcome. Certain medications need to be administered to the animal in a specific way on order to be effective. For example Baytril may be given by mouth (per os/PO) or by intramuscular (IM) injection. Fortum on the other hand is never given by mouth, but rather by IM injection, intravenous (IV) injection or indeed subcutaneous (SC) injection. The route the drug is given will affect speed of uptake or absorption as well as duration of action and all of these factors are taken into consideration when dispensing such medications. The owner’s willingness and capability in administering injections if required for extended treatment at home often influences the choice of medication dispensed also. The species in question may determine what route to use also. Anyone who has tried to orally dose turtles and tortoises will tell you it is often not an easy task so this route may be avoided in order to ensure owner compliance with medicating their animal. The oral route in lizards however is much easier, so is often preferred over repeated, painful injections which the owner may struggle performing and which are not without risk especially in smaller species. The oral route in snakes is controversial and several studies have demonstrated that it is not entirely effective in many cases. This is due to the unique nature of the digestive tract in snakes that remains in a quiescent state for long periods between meals and therefore does not absorb medications as effectively or predictably as in lizards and chelonians for example that are designed to eat continuously on an almost daily basis. Therefore in snakes I invariably prescribe injectable antibiotics and teach the owners how to do this safely and effectively at home, or hospitalise the patient if this is not practical. A word on injecting Baytril is prudent at this stage. This is an alkaline drug and does cause some pain/discomfort on intramuscular injection, so in snakes in particular where the oral route is least preferable, I will often use Fortum or Amikin injections as a first choice if necessary. For lizards with an R.I., I will invariably use Baytril by mouth as my first choice, unless culture/sensitivity results tell me otherwise. Finally the frequency of dosing is dependent on the drug and dose chosen and can vary. Whatever drug, dose route, frequency and duration of treatment are prescribed, it is vital to stick to this and finish the course. If you have researched and found evidence or material to the contrary to what has been dispensed for your animal, ask your vet about this before deciding to change the treatment. I would also urge you to attend follow up appointments as requested, even if you think your animal is better.

Supportive care is critical in treatment of any ill reptile, and in severe cases I will often hospitalise the animal in controlled conditions particularly when starting treatment. Correction of dehydration is one of the first concerns for many patients. If the animal is anorexic I may tube feed using proprietary convalescent diets appropriate to the species in question. In some cases I will place an oesophagostomy tube which allows syringe feeding through a tube in the side of the neck directly into the stomach without stressing the animal in question. This is a particularly useful tool in anorexic debilitated tortoises. In delicate or stress-prone species such as chameleons, sometimes hospitalisation can be counterproductive. Each case is judged individually, and according to the owners comfort and ability to treat at home. Nutritional deficiencies may be corrected by multivitamin and mineral injections or supplementation. Hospitalisation also allows daily nebulisation in certain cases, particularly useful in chronic or deep-seated pneumonia cases. Nebulisation is a useful tool which can be used in both the hospital and home environment and involves vapourising anti-microbial drugs and exposing the ill reptile to this vapour in an enclosed chamber to inhale the drug and therefore achieve better penetration of the airway then by systemic treatment alone. Lung tissue penetration by systemic drugs can be difficult for various reasons. The blood-air barrier in reptile lungs is thicker than that of mammals, as well as the tendency in these species to form solid caseous (cheese-like) pus or infectious discharge deep within the lung tissue, rendering the infected areas almost impenetrable by blood-borne drugs. A number of antibiotics can be used for nebulisation including Amikacin, Gentamicin, and Enrofloxacin (Baytril) amongst others. The disinfectant product F10 which is bactericidal, viricidal and fungicidal has been demonstrated to be an effective agent for nebulisation in R.I. cases, although care must be taken to use the correct product and concentration according to manufacturer guidelines. This agent can also be used for nasal flushing in cases of upper airway disease with excessive nasal discharge or secretions. Depending on the case nebulisation may be carried out 1-2 times daily for a maximum of 20-30 minute sessions. Other drugs that may be nebulised apart from antibiotics and antiseptic-disinfectants include steroids for anti-inflammatory action, bronchodilators such as aminophylline to open the airway prior to nebulisation with other agents and finally mucolytic drugs to reduce the viscosity of respiratory secretions. Intrapneumonic therapy is even more aggressive and involves direct administration of drugs into affected lung tissue using endoscopy in the airway or gaining access via an indwelling catheter to the site of lung lesions. This is generally carried out on tortoises under sedation or general anaesthesia, locating the exact location of lung lesions by X-ray or ultrasound and drilling through the carapace.

If parasitic infection is responsible for respiratory disease, then treatment is directed at killing the parasites and preventing re-infection, as well as minimising the side effects of treatment. Nematode infections are generally treated with a number of anti-parasitic drugs including Fenbendazole, Albendazole and Ivermectin. Ivermectin must NEVER be used in chelonians as it is toxic and can cause fatal side effects. Anecdotal evidence for adverse effects of this drug in chameleons also exists so for this reason I generally avoid it in these species. In severe parasitic infections treatment itself can cause further problems especially where migrating larvae ore killed in-situ and subsequent inflammatory processes surrounding the dead parasites can cause more severe clinical signs than the parasitic infection itself. Viral infections can be difficult to treat and often rely on supportive care and prevention of secondary infection, in an effort to allow the animal to clear the infection if possible using its own immune defences. Some anti-viral agents are available, but their use in reptile patients is not widely researched and they are also often cost-prohibitive in general practice. Anti-fungal agents such as ketoconazole and itraconazole can be used to treat fungal disease but accurate dosage is critically important as side effects can be severe if used incorrectly or if the animal is debilitated to begin with.

As you can appreciate, blanket treatment protocols for respiratory disease are impossible to supply so care must be taken when following such guidance from other hobbyists or information obtained online. Each case has its own intricacies and possible underlying causes that may be missed without appropriate investigation at the diagnostic stage. I also hope I have outlined the difficulties in achieving a cure for respiratory disease in reptiles in some cases despite the best possible treatment. By far the best advice I can give is to ensure husbandry and nutrition of reptiles in your care is ideal, particularly with regard to space, ventilation and heating. Proper biosecurity precautions should be put in place in any large reptile collections, to include strict isolation and quarantine of any new additions for a minimum period of 6-8 weeks, preferably longer. Daily observation goes a long way in determining when a reptile is showing signs of illness, and prompt treatment by an experienced reptile veterinarian is often critical in order to achieve a successful outcome.


Step right up! Behold a Two-headed Snake!

Clients of mine who breed corn snakes recently had this very unusual baby hatch out of an egg in their incubator, a two headed snake! The hatchling appears to be a pair of conjoined twins which is very rare indeed. We occasionally see two-headed snakes hatching and it is usually a random event; a freak coincidence causing fusion during early embryonic development known as polycephaly.


In any case, most two headed snakes look to all intents and purposes like a single snake body with two heads side by side on a single neck. This hatchling however is conjoined much farther down the body, just above the level of the heart so it appears from X-rays I took that each head has a separate throat, windpipe (or trachea) and oesophagus that carries food to the stomach. This most likely resulted from fusion of monozygotic or identical twins during the early stages of development within the egg. It was extremely difficult considering the tiny size of the creature to obtain good diagnostic quality X-rays especially as the animal was conscious and difficult to keep it still to take a shot, so the exact anatomy is still unclear. I didn’t want to risk anaesthetising such a fragile, tiny creature just for interest sake to look at its anatomy but from what I can make out it seems like there is one dominant animal with relatively normal anatomy and the other has fused just above the level of the heart. I think there is a single heart, stomach and other abdominal organs, although there is a lot of air so there may be two lung spaces, unusual in that snakes usually only have a single functional lung.


Other problems that are evident are that the spine is kinked in a few places, which may cause problems down the line, although plenty of minor kinked snakes do lead perfectly normal and pain free lives. The good news is that the little snake has now eaten its first meal, and appears to be doing well. Whether it survives long term is still unknown however. There could be invisible problems we are not yet aware of. If it does survive it would be very interesting to perform more advanced imaging such as MRI to determine the anatomy, but of course this is all academic as there would be no benefit to this little snake, or should I say snakes! Surgical correction is not possible and would result in the death of one or both animals. The main concern in the near future is whether quality of life can be maintained.

More information on the underlying causes can be found here:

Can you see my heart beating? A snake with a very big problem!

Snake transport box

I received an unusual phone call recently from the owner of an 18 month old False Water Cobra (Hydrodynastes gigas), a South American rear-fanged, mildly venomous species of snake ( The owner had noticed shortly after acquiring the snake that it had what was described as a wound on it’s underside through which you could see it’s insides! Naturally, I was quite worried so asked for the snake to be brought in for examination, and in the meantime they emailed me some photos and reassurance that the snake was acting perfectly normally, eating and defaecating fine and didn’t seem in any way bothered by the strange ‘wound’.

False Water Cobra Hospital Vivarium on AdmissionFalse Water Cobra Hospital Vivarium on Admission 1

Having examined the animal, it appeared that she had a defect in the body wall on her ventral surface or belly with a large hole visible in the ventral muscles. Bizarrely, this defect was at the level of the heart about a third of her length down her body. The only tissue separating her visibly beating heart from the outside world was a thin membranous layer of body cavity lining and some connective tissue which was quite transparent. I have seen some similar lesions in reptiles at the umbilicus or site where the blood vessels carry nutrients into the growing embryo from the egg or from maternal tissues in the case of live bearing species. Sometimes when these animals hatch or are born the hole in the body wall fails to close completely and an umbilical hernia or body wall defect is left behind. However, I have never seen or even heard of such a defect high up on the body overlying the heart! I concluded that this must be a congenital problem that the snake was born with, perhaps a fluke genetic mutation or a developmental insult during incubation of the egg which disrupted the normal growth of the embryo resulting in a physical abnormality at birth. Having spoken to a few reptile enthusiasts in the UK who keep this species of snake, it turns out there have been a few reported with the exact same defect in the exact same place, so it looks likely this is a genetic problem, most likely caused by inbreeding in certain lines due to relatively low genetic diversity in the UK population.

Snake membranous hernia before surgery

The risk of leaving the snake in this condition was that during the course of her life she may snag this fragile membrane protecting her heart and eviscerate herself or worse still puncture her heart. Although this risk was small, it would be safer to carry out a surgery now than always wonder and worry if she might do some damage and seriously injure herself, when pulling off her shed skin for example. I admitted her and set her up in our reptile ward in a heated vivarium to bring her body temperature up to preferred range. Once her temperature was correct I injected her with a combination of sedative drugs into the muscle in her back. I say I injected her, but actually I restrained her with a thick pair of gloves whilst my nurse Justyna gave her the injection. She was very feisty, strong, and objected to restraint, trying to bite the gloves. Obviously considering her potential to give a painful bite and possible envenomation we took great care at this stage. Rear fanged snakes are different to other venomous species in that they have modified salivary glands and teeth at the back of their mouth, with which they chew their prey in order to inject and subdue it. Therefore it would be difficult to get a dangerous bite  from a rear fanged species unless you allowed the snake to chew on you. Front fanged species can deliver a dry or wet bite from the front of the mouth with a rapid strike and minimal contact so are far more dangerous to work with and handle. After her injection we left her back in her hospital vivarium in the correct temperature to allow her to metabolise the drugs efficiently. Ectothermic or ‘cold-blooded’ animals such as reptiles rely on external temperature to control their biological functions and metabolic rate, so it is vital when treating ill specimens and indeed when undertaking anaesthesia and surgery to maintain their body temperature in the correct range so everything runs smoothly and drug dosages work effectively. After about a 20-30 minute induction period, now nice and relaxed after her sedation we removed her and placed her into an anaesthetic gas chamber so she fell further asleep and we could position and prepare her for surgery. She was maintained under anaesthesia by using a gas mask delivering a safe gaseous drug called Sevoflurane. Normally for a prolonged surgical procedure in a snake I would intubate the animal with a solid plastic or rubber tube placed into the windpipe or trachea for better control and access to her airway should she stop breathing for instance, but in the case of venomous species I prefer not to mess around in the mouth due to the risk of accidental envenomation. A correct sized mask with her head taped inside in place and sealing the entrance provides the next best option and is safer for all involved.

Snake anaesthesia preparing for surgery


Here’s a video link showing the heart visibly beating underneath the membranous layer of the abdominal wall defect:

Once Justyna prepped her with a surgical scrub and insulating layers to maintain her body temperature lying belly up on a surgical heat mat, I was ready to begin. I carefully dissected away the thin membrane covering her heart from the scales on either side of the deficit. I had to be extremely careful as this layer of tissue was so thin and the heart was literally beating against it directly underneath. Tiny blades and scissors were required, and I cut in time between the beats to avoid cutting at the moment the heart filled to maximum capacity with blood. Myself, Justyna and the veterinary student who is seeing practice with us this week to learn more about exotic pet medicine were all holding our breaths at times. Credit to the student Conor for taking the photographs while I operated by the way. Justyna found this anaesthetic very easy to monitor throughout as we were literally watching the heart beating throughout so she could record heart rate and strength with the naked eye for a change! Often we use sensitive probes to monitor heart rate through the body wall but not needed in this case.

And here is a video during the surgery when I had carefully dissected away the thin tissue revealing the heart beating underneath before I began to suture the defect closed:

Once the tissue had been separated away from the half sized scales lining either side of the lesion I set about suturing the hole back together, bringing the soft tissue of the internal body wall and the edges of the scales together to meet in the middle and form a tight seal which would heal and protect the heart and blood vessels underneath. I was quite happy with a neat and tidy job at the end. She was given a long acting pain medication and anti-inflammatory by injection, and a reversal drug for the sedatives given earlier and placed back in a clean dry cage with paper substrate to recover. We turned up the heat temporarily to boost her metabolic rate and aid her clearance of the anaesthetic drugs, and within 20 minutes she was groggy but wandering around her cage getting her bearings again. It always surprises me how tough these animals are. Reptiles have been around for millions of years and they really are quite resilient and remarkable in what they can withstand. Many of my clients fret and worry about anaesthetic risk in particular if their pet reptile needs a surgery for example. Although the general risk is higher than in dogs and cats I find them to be remarkably sturdy anaesthetic patients for the most part, so the risk is still quite low as long as you seek out an experienced and knowledgeable reptile vet.

Snake repair after closure


In terms of aftercare, she just needs to be kept clean and dry. No antibiotics were prescribed as it was a sterile op and good hygiene practices should prevent infection from here. Being a semi-aquatic species that likes to bathe in water, I’ve specified that she is not allowed a water dish in which she could submerge as the wound could act as an entry point for water and bacteria or other contamination into the body cavity if she submerged in the coming week or so. I will keep her in overnight and send her home tomorrow. So far she is making an excellent recovery. The sutures I placed are dissolvable over time and should slough off the next time she sheds her skin or possibly after that, so I just need to recheck her in a week to make sure the wound looks good, is healing well and is free of infection. Problem solved!

Snake in recovery

An Introduction to Amphibian Medicine

I recently gave a talk to veterinary students at the Royal Veterinary College Zoological Society in Camden, London which was also video linked to their Potter’s Bar/Hawkshead campus about amphibian medicine and why it is relevant, not only in private practice but also on a global scale in conservation and laboratory research. Below is the link to the presentation, which outlines some of the topics I discussed:

Any questions are welcome in the comments section. Feel free to share.

Thiamine (Vitamin B1) Deficiency in Garter Snakes

Neurological garter snake

Neurological garter snake

This week I was presented with a sub-adult red-sided garter snake (Thamnophis sirtalis infernalis), a North American species of snake which feeds primarily on fish and amphibians in the wild. In captivity these snakes are often fed on fresh or defrosted fish, as well as earthworms, live goldfish or other feeder fish such as minnows or guppies, and pinkies or baby mice.

The snake had suddenly shown a minor head tilt and by the following day was found turning upside down unable to right itself. The owner who is quite knowledgeable on reptiles brought it down immediately for me to examine as timing is of the essence in treating reptile patients. Often they hide signs of illness until a disease is quite advanced, due to being prey species in the wild, so the owner recognised the urgency of seeking veterinary treatment.

The most common differential or suspected diagnosis for a presentation such as this, a garter snake with neurological signs, is a thiamine (Vitamin B1) deficiency associated with captive diet provision.  A deficiency in this vitamin leads to inflammation and destruction of cells in the central nervous system resulting in symptoms such as head tilt or wobble, torticollis (twisting of the neck), opisthotonus (stargazing), nervous tremors, incoordination, convulsions, apparent blindness and death.

In the video link below on my Facebook account you can see how the snake was off balance and incoordinated, as well as ‘stargazing’ or throwing it’s head back over it’s body to the sky:

The issue with captive diets is that they often rely heavily on a single, readily available species of fish. Many fish species, both freshwater and saltwater, contain an enzyme called thiaminase which degrades thiamine or vitamin B1 from the diet. If such species are fed over long periods a deficiency in this vitamin occurs causing the clinical signs outlined above. There is some confusion as to the role of freezing and defrosting fish to feed to garter and other piscivorous or fish-eating snakes such as the water snakes (Nerodia spp.) as well as freshwater turtles and terrapins that rely heavily on fish based diets. In certain species of fish the naturally occurring thiaminases in the flesh are not destroyed by freezing, therefore when they are fed exclusively the thiamine in the diet is depleted and deficiencies occur. Some loss of thiamine in frozen defrosted fish can be prevented by defrosting the fish in hot water (80C for 5 minutes) which denatures the enzyme, although this has some disadvantages in that it can reduce the nutritional value of the food further. Some owners will add a vitamin B1 supplement to the food to counteract the depletion of thiamine. However, the best option for feeding fish to piscivorous reptiles is to feed fish species which have very little or no thiaminase enzyme in the first place. Many readily available and traditional food choices for garter snakes are poor choices due to their thiaminase content, feeder goldfish being a perfect example. Goldfish actually contain high levels of thiaminase despite being the most widely available feeder fish and most widely recommended for garter snake food!

The owner of the snake I treated this week fed frozen defrost Smelt to her garter snakes, along with fresh trout and salmon. All of her garter snakes were very healthy and thriving on this diet so there was some confusion and disappointment as to why I thought this one had succumbed to hypovitaminosis B1. It turned out that this particular animal was quite a fussy feeder compared to the other individuals and rarely accepted a meal of trout or salmon, but rather fed almost exclusively on the defrosted Smelt. Smelt is a readily available frozen feeder fish, which contains relatively low levels of thiaminase compared with many other sources such as mackerel, goldfish or whitebait, but if fed exclusively for long periods can result in the thiamine or B1 deficiency over time. My plan for treatment was to administer high dose injections of Vitamin B1 and monitor the response to treatment. A positive response to treatment with reversal of the clinical signs confirms the diagnosis in these cases. I gave two injections 3 days apart, the second of which was today and already the little snake is doing much better; more alert, responsive with normal coordination and mobility, and no longer twisting or flipping over. Only a very mild head tilt remained, which I anticipate will have disappeared once it comes back at the end of the week for the last vitamin injection. In severe or advanced cases the neurological damage can be too severe that the central nervous system particularly the cerebral cortex of the brain becomes necrotic and the animal fails to recover. Luckily in this case the vigilant owner brought the patient in in time to save it.

Garter snake recovered and moving normally

Garter snake recovered and moving normally

In future, I recommended Smelt should only be used as an occasional convenient source of food, not as a regular component of the diet. The owner will have to make efforts to introduce more variety into the snakes diet with earthworms, pink mice, feeder fish species that lack the thiaminase enzyme such as guppies and platies, or commercially available fresh and frozen fish species again that lack thiaminases such as trout and salmon and some other native freshwater angling species. It may be difficult to convert this fussy feeder onto new food sources, in which case the Smelt could be used to scent new foods until they are readily accepted.

Here is a video of the snake after three vitamin B1 injections a week later, moving much more normally, more alert and responsive than before:


For further reading on this topic have a look at these links:

Click to access gsnakecare.pdf


Renal Tumour in a Chameleon: A Case Study.

A one year old male Panther Chameleon presented to the clinic following a one week history of progressive hind limb weakness, loss of motor function, swelling of the left knee and sleeping with his back legs dangling from his branch. He was still eating although his appetite was reduced. His owner was very knowledgeable and experienced in keeping reptiles, and his husbandry and captive care sounded excellent when taking a full clinical history and appraisal. There had been no changes to his routine or care, and no known history of trauma. His left knee joint however was visibly enlarged and swollen compared with the right hand side.

Hind limb paresis unilateral swollen stifle

On clinical examination, the joint was swollen but didn’t appear painful on palpation. However he was demonstrating bilateral hind limb paresis, or loss of motor function. Gripping was much reduced in the back feet compared to the front, and he appeared much weaker on the pelvic limbs also. Similarly he was reluctant to bear weight on the left hind compared with the right. Sensory function was intact and present in all limbs. This examination allowed me to form a reasonable diagnosis of a neurological problem, most likely a spinal lesion in the lumbar region or an intra-abdominal mass placing pressure therefore impinging on the nerves in this area resulting in compression and subsequent loss of motor function. I should mention here that I had seen a photo of this chameleon on a forum I am a member of the previous day when the owner asked for advice. From a photo alone it would have been impossible for me to pinpoint the problem or give a reasoned diagnosis as I could when the animal was in the clinic and I could perform a full neurological examination. For this reason I would always warn owners to beware accepting an online diagnosis based on a photo alone. If in doubt, a vet visit with a reputable reptile vet is really worthwhile.

Hind limb paresis perching

I explained to the owner that based on the issues I was seeing, I suspected an abdominal mass was the worst case but highly likely scenario, so we decided an X-ray was the next step. I took a dorso-ventral view after giving the chameleon some anaesthetic gas to allow me to tape both legs in position so I could get the best image possible to compare the knee joints in the same position. The X-ray however showed a very serious and obvious problem quite apart from the swollen joint. The entire abdomen of the lizard was full of air and the internal organs were all compressed. Air on an X-ray is black, and in normal chameleons the lung shadows demarcated by free gas extend a little over halfway down the length of the abdomen. Chameleons are fairly unique in that they also have finger like extensions or air sacs extending very far back towards the tail end of the body which are lined with a very thin transparent tissue almost like cling film. Therefore this is very prone to rupture from trauma, infection or damage during surgery for example.

DV view

I took a lateral view to confirm the organs were compressed ventrally (towards the bottom or belly of the abdomen), which highlighted that in fact a lung or both lungs were ruptured and air had leaked into the free space within the abdomen. I was also curious to gain another view of the very dense whitish-grey mass in the caudal or tail end of the abdomen just before the pelvis, which was occupying the entire width of this section of the abdomen. Unfortunately, on the lateral view this corresponded to the site of the kidneys and confirmed my worst fear that a kidney mass of some description was responsible for the nerve impingement and neurological signs on presentation. The kidney mass may have been an abscess or a congenital problem such as hydronephrosis present from birth which was gradually causing a growth in size over time. Similarly it may have been a tumour but it was difficult to tell from X-rays alone. The swelling of the joint in the left knee could have been explained by trauma associated with reduced motor function, the assumption being that he injured it in the preceding days whilst dragging it behind him.

Lateral view

The prognosis based on a renal or kidney mass of that size no matter what the underlying cause was unfortunately quite grim, not to mention the issue of air within the abdomen causing breathing problems and compression of other vital organs. After lengthy discussion with an upset owner, it was decided that it would be fairest and most humane to put the chameleon to sleep and prevent further suffering. Any treatment or further diagnostics would have had to be very invasive and highly unlikely to bring a resolution to the problem. In order to bring a resolution to the case and for the sake of education, the owner kindly allowed me to open the abdomen following euthanasia in a post mortem examination to confirm my diagnosis of a renal or kidney mass, and ascertain the nature of the lesion. Sadly my suspicion of a renal tumour was confirmed; quite a surprising diagnosis in such a young animal you might say. However renal lymphoma, which is one of the more common cancers in reptiles, is unfortunately not exclusive to older animals as in many other cancers. Several other cancers are also reported in reptiles. In this case, the classification of the tumour would not affect the outcome of the case so I did not send any tissue samples for pathological classification. A very sad case, but the positives if any can be taken from it were that I and hopefully other veterinarians can learn from this little chameleon’s death. I’m therefore very appreciative to the owner for allowing me to write this up and share the case study.


PM findings labelled

Frog Enucleation: Eye Removal Surgery

Eye surgery

Eye surgery

Splat the albino horned frog (sometimes called Pacman frogs because of their large mouth and appetite!) somehow injured his eye, presumably by jumping into one of the furnishings in his vivarium. Unfortunately, the eyeball itself was ruptured and could not be saved so it had to be removed, or enucleated. Here he is in an anaesthetic bath containing dissolved anaesthetic drugs that he is absorbing through his skin.

2 Once anaesthetised, I also injected some local anaesthetic around the eye socket and behind the eye itself. He had earlier been given pain relief and antibiotic injections to ensure he was comfortable and to prevent infection. I carefully dissected out the eye from the underlying ocular muscles lining the eye socket. 3

Once the eye had been removed, I placed collagen implant into the socket and packed it well to prevent bleeding and allow the remaining space to fill in with new tissue as it heals. At this point we started to rinse Splat in order to start the process of recovery from his anaesthetic.


Here he is after the surgery having closed the eyelids with dissolvable suture material. Now it was time to recover him and wake him from his operation.


We placed him in clean, de-chlorinated water and irrigated him regularly whilst keeping him warm in order to dilute the anaesthetic residue in his skin and keep him maximally hydrated so that he could recover and wake from anaesthesia. He recovered well, and went home the next day having been given another pain relief injection and oral antibiotic drops for the owner to administer. Here’s hoping he will be fighting fit in no time!

The snake that became unstuck!

Crystal the Royal python got in a rather sticky situation, when she managed to tangle herself in some loose duct tape that was being used temporarily in her vivarium when her owners were installing new lights. Unfortunately in her bid to untangle herself she managed to rip the delicate thin skin on her neck and caused a full thickness laceration exposing the underlying muscle. Her owners were panicked and rushed her down to see me, travelling nearly 3 hours in traffic to get to the surgery. Luckily it was my turn to work the Saturday clinic that day and my afternoon wasn’t as busy as usual so we managed to see her quickly and fix her up before more damage was done.


Snakes and sticky tape do not mix

Here she is being given some anaesthetic gas and oxygen, after initially being given sedative drugs via intramuscular injection. At this point we couldn’t see the true extent of her injury, but knew it was bad. I was confident however that we would stitch her up and have her reasonably back to normal in no time. I took the opportunity while she was going under anaesthetic to administer pain relief and antibiotic injections to make her comfortable and prevent infection setting in.


Snake laceration wound

Once she was fully anaesthetised I used surgical spirit to dilute the solvent on the tape and peel it off bit by bit, taking great care not to allow any spirit to contact her delicate tissues underlying her scales or to cause further tears. After removing the tape the area was cleaned and disinfected and prepped for surgery, reducing contamination and minimising the risks of post-operative infection. She was kept on a warm heat pad throughout the procedure to enable her cold-blooded body to maintain it’s metabolism and process the anaesthetic and other drugs effectively. Reptile patients are unique in that all bodily functions rely on external heat from immune function, to heart rate and even breathing rate. Therefore it is vital that they are warmed throughout surgery and maintained in thermostatically controlled conditions whilst hospitalised and in recovery.


Suturing snake wound

I carefully sutured her skin back together taking care not to cause too much tension and not to invert the scale edges so that the wound could knit back together efficiently and heal quickly. Good surgical technique at this stage was critical to obtain a cosmetic and functional wound that would repair over the coming weeks without causing future problems with shedding skin for example.


A vet’s work is never done, even on a Saturday evening

Here I am hard at work on a Saturday afternoon whilst all my colleagues (apart from my nurse Sharon assisting on anaesthetic duties) were out in the back car park starting our end of summer barbecue, beers and wine in hand. Now there’s dedication, eh?!


Python in recovery hospital cage

After she was stitched back together I reversed her sedative drugs with another injection and set her up in a warm hospital cage on a heat pad to recover from her ordeal. By this point her meds ensured she would awake pain free within a couple of hours. Things are definitely slower in my reptilian patients compared with dogs and cats.


Snake wound sutured post-op

This was the finished handiwork post-operatively. I am happy to say she went home very alert and happy on the Monday morning to her relieved owners and will come back to visit me to remove her sutures in 4-6 weeks.

Cardiac Disease in Reptiles

I would like to share with you two interesting cardiac cases in reptiles which I encountered in the past, both causing heart failure but with different presentations, underlying disease mechanisms and outcomes. Cardiac conditions in reptiles are rarely seen, possibly due to under-diagnosis or not being presented frequently to specialist reptile clinics. This could also be due to various other illnesses and diseases causing the death of pet reptiles before they reach the grand old age when they are likely to present with cardiac failure.


In any case, I was very surprised to see both of the following cases within two weeks of each other, when in my previous three years of clinical practice I have rarely encountered such problems in reptile species. The first case was a 5 year old female Yemen Chameleon named Blossom. Blossom is an old girl for her species and has now laid 6 fertile clutches of eggs which is a great achievement in itself and a credit to her owners excellent knowledge and care for these specialist reptiles. Chameleons do not make easy pets, but especially females as they often get reproductive and metabolic problems. In fact, Blossom’s owner was concerned that perhaps this time around Blossom was egg-bound or unable to lay her next clutch as she was mated 10-12 weeks previously and had failed to lay any eggs. She was also quieter than usual, had a decreased appetite, was showing darker stress colouration, and her abdomen was becoming enlarged suggesting she may be gravid (carrying eggs).

When Blossom presented to the clinic her physical examination was unremarkable apart from a distended abdomen. I decided to take an X-ray to determine whether she was indeed gravid or egg-bound, or suffering from a condition called pre-ovulatory stasis whereby the ovaries produce multiple follicles but fail to ovulate and progress to laying a clutch of eggs. I was extremely surprised to find that the distended abdomen did not contain eggs or follicles but was full of fluid creating a grainy, diffusely opaque greyish appearance throughout the abdomen and obscuring the abdominal contents. The striking finding on the X-ray however was an enlarged perfectly spherical cardiac outline suggesting heart enlargement. More specifically this appearance indicated an accumulation of fluid in the pericardium or thin membranous sac that surrounds the heart rather than enlargement of the heart itself obscured within this fluid sac.

chameleon pericardial effusion A diagnosis of pericardial effusion was made, which has most likely resulted from primary cardiac failure due to old age and high metabolic stresses or demands throughout Blossom’s life. Secondary fluid accumulation in the abdomen called ascites has resulted from the failure of the heart to pump blood as effectively as normal. This inefficiency in the pumping mechanism leads to fluid pressure building up in the vessels leading to the heart and subsequently fluid leaking from the blood vessels into surrounding tissues and organs, eventually accumulating over time in the abdominal cavity. Other causes for pericardial effusion can include parasitic disease and infection but considering Blossom’s relatively bright demeanour, history, husbandry conditions and age these are unlikely causes in this case. Unfortunately for Blossom this does mean that she has congestive heart failure, which will inevitably worsen with time.

Treatment for congestive heart failure in reptiles is difficult and not a great deal of research has been carried out on the various drugs available in terms of efficacy and safety. The mainstay of treatment in such congestive heart failure cases where fluid accumulation is the most problematic clinical sign is the use of diuretic medications, which encourage elimination of excessive fluid from the body. Unfortunately, the risks of diuretic treatment in reptiles are higher than in mammals as they have a specialised renal system with a unique blood supply to the kidneys. This can therefore render them susceptible to dehydration and kidney failure on diuretics or other medications. Similarly, because treatment would involve injecting Blossom with medication 2-3 times daily, myself and the owner agreed that this would be unfair and cause her far more stress and pain than was humane considering chameleons make for stressful patients at the best of times. At present Blossom is doing well without treatment, so as long as she remains comfortable and her breathing is unaffected we will monitor her progress. I have suggested decreasing the temperatures in her vivarium to the lower end of her preferred optimum temperature zone, and also advised reducing her food intake. Both of these alterations in her husbandry are an attempt to decrease the metabolic demands on her cardiovascular system and hence try to prolong her lifespan as much as possible whilst keeping her comfortable. It will be interesting to see how long she remains healthy and bright, but sadly there may come a time where she dies of acute cardiac failure or we have to consider euthanasia when her breathing or quality of life is compromised. At this point the fact that Blossom has thrived, reproduced and lived beyond her natural lifespan in the wild to succumb to a geriatric disease rarely seen in captive reptiles is a credit to her owners excellent care.

Blossom Chameleon









The second cardiac case I saw was an old cornsnake, of unknown age due to being rehomed as a mature adult snake. I do not have as much background information for this case as it was seen by a colleague in my previous practice. The snake presented with lethargy and inappetance, having refused food for several weeks. The striking physical exam finding was a large firm swelling in the cranial third of the body corresponding to the site of the heart or possibly the stomach. X-rays (seen above and below) revealed a soft tissue opacity in this region suggesting one of either of these organs was grossly enlarged. Due to the appearance on the X-ray a foreign body ingestion in the stomach could be ruled out. Unfortunately the snake died in clinic so after discussion with the owner a post mortem exam was carried out which revealed the enlarged organ to be the heart. All three chambers of the heart were massively dilated to about three times their normal size and the ventricle was grossly thickened and enlarged. As an aside mammals and birds have four chambers of the heart compared to three chambers in reptiles and amphibians, and just two in fish!

Cornsnake DCM dissectionA diagnosis of dilated cardiomyopathy was made which lead to acute cardiac failure and death in this animal. If the snake hadn’t died this diagnosis would have been made by doing an ultrasound scan to determine what indeed the enlarged structure was. Another possibility I would have been concerned about in this case before seeing the X-rays was a parasitic infection called Cryptosporidiosis which can cause a large swollen stomach in infected snakes manifesting as a firm mid body swelling on physical examination. Again, the most likely cause of cardiac disease was degeneration of the heart and valves associated with ageing. If the snake had presented at an earlier stage of the disease treatment with cardiac medications may have been attempted but unfortunately in this case it was too late.

Cornsnake DCM Lateral 1I hope you found these case studies interesting, and if you have any questions or comments please feel free to ask in the comments section below. Similarly if you have any topics you would like me to write about in future let me know.