Case Study: Follicular stasis & secondary impaction in a Uromastyx lizard

Uromastyx 1

This Uromastyx lizard presented to me almost two weeks ago for constipation, having not defaecated in several days which was highly unusual for her. She was extremely bright and well, with a good appetite and no other changes in behaviour. There was no obvious mass or obstruction on abdominal palpation which may have indicated a blockage, foreign body or tumour although her abdomen was quite distended. After discussion with the owner it was decided to trial conservative treatment by giving her a liquid paraffin enema and feeding her more at home on her food. Unfortunately as she was so stubborn and strong I failed to convince her to open her mouth to pass a stomach tube to give liquid paraffin directly. Strong little lizard!

She came back several days later having still not passed any significant amount of faeces, so I decided to perform an X-ray to visualise her internal abdomen and find out what was wrong. The X-ray revealed that she was impacted with opaque white, gritty sand material visibly transversing the mid abdomen in her intestine. I was also quite suspicious of the large greyish spherical masses occupying her abdomen as they looked like they may have been ovarian follicles.

Uromastyx 2

I hospitalised her to allow me to pass liquid paraffin directly each day with the aid of some anaesthetic gas so I could open her mouth without causing undue stress or damage, and repeated the X-ray two days later. She had by now stopped eating and although she was still very lively we needed to know whether the impaction was resolving with medical management or would we need to be more aggressive with treatment. She had produced some small amounts of faeces whilst hospitalised so I knew it was a partial obstruction most likely rather than a complete blockage. I tested her faeces for parasites as sometimes intestinal worms can cause sluggish gut transit and impaction issues but she was negative for any parasites. The clinical picture didn’t fit very well though in that the impaction had not moved or progressed. It was in the same location and if anything appeared denser and more compact. More importantly, the abdomen itself was now less inflamed so gave a clearer view of the suspected follicles. It was decided to perform an exploratory surgery to spay her to treat the follicular issue as well as trying to sort out the impaction.

Upon opening her abdomen and carefully inspecting the contents, it was obvious what had happened. She had produced lots of large mature ovarian follicles in preparation for breeding. This condition is known as pre-ovulatory egg binding or follicular stasis, and is life threatening if left untreated. In this case one of the large follicles had looped over a length of intestine, pulling on it therefore causing compression. Food material and some loose ingested substrate which normally would have passed out in the faeces then accumulated upstream of the rogue follicle that was weighing down the intestine. I managed to pass the offending follicle back through the intestinal loop it had become entangled in and proceeded to remove both ovaries and follicle masses. There were 14 in total and they were proportionally the largest ones I’ve ever removed from a lizard. After the pressure was off the intestine I could massage and break up the impacted material and ‘milk’ it down the intestine. I decided not to open the intestine at this stage as was confident she would now be able to pass the offending material. There would have been a huge infection risk of opening the intestine in any case. Here are the offending follicles attached to each ovary which I removed:

Uromastyx 3

I reversed her sedative drugs and took her off the anaesthetic gas to recover, after giving her some warm subcutaneous fluids to replace blood and fluid loss during the surgery. She recovered remarkably well, and was kept in overnight for post-operative monitoring. She was discharged the next day with instructions to house her in a sterile vivarium with paper substrate while her wound is healing. When she came back for post-op check the other day she was full of energy and very bright. Her owners were a little taken aback to see the size and number of follicles that had to be removed! Here she is in recovery and later happily posing with her bounty at the post-op check:

Uromastyx 4

Uromastyx 5

Hopefully she will have no further reproductive problems now her ovaries have been removed. I say ‘hopefully’ as when spaying lizards there is always a small chance some ovarian cells could be left behind and regenerate. The anatomy means that it can be tricky to place ligatures between the ovaries and surrounding structures without causing damage or catching some ovarian tissue in the ligature itself. On one side of the abdomen the ovary lies in close proximity to a large vein and on the other the adrenal gland. So it is a technically challenging operation, but one that brings great satisfaction when it results in a successful outcome.