Rabbit Malocclusion

This week I had one of my regular patients in for a dental procedure, Jack, a 5 year old Netherland Dwarf rabbit who weighs less than 1kg! Unfortunately for Jack he suffers from malocclusion of his incisor teeth which means that they grow in the wrong direction due to the conformation of his skull. Dwarf breeds of rabbit are particularly prone to this problem due to selective breeding for smaller size and rounder faces.  Because rabbit’s teeth grow continuously throughout their lives, if they are misaligned and not constantly wearing or grinding against one another when eating coarse fibrous foods then they will overgrow and can cause big problems.

Jack has been coming to the clinic for a long time (every couple of months at least) to have his incisors or front teeth trimmed. His lower incisors extend out of the mouth in front of his upper incisors instead of being tucked behind like in a normal healthy rabbit, therefore they become massively overgrown and one in particular that doesn’t come in contact at all with the corresponding tooth in his upper jaw gets so large it looks like a large tusk protruding from his mouth!

Up to this point Jack tolerated trimming of the teeth whilst awake with our electronic dental burr to bring his incisor teeth back to a normal length. Occasionally after dental exams we would give him sedation so we could burr and sharp spurs that were forming on his rear teeth or molars also as he would not tolerate this conscious, nor would we be able to see what we were doing in his tiny mouth without dental gags and a sleepy patient.

It was decided after the last treatment that because the trimming is becoming more frequent as he ages, and his risk for anaesthesia is also getting higher with age that this week we would attempt to remove these incisors once and for all. His molars have also been getting worse with time and it may be exacerbated by the fact he is finding it difficult to eat at times when his incisors get too long again. This is a bit of a tricky operation and not without risk, so we didn’t undertake it lightly. Rabbits tend to do very well without their incisor teeth however as they are mainly used for grasping and cutting long fibre food. The lips however are very prehensile and work well to grab food and bring it into the mouth in the absence of these teeth. I was confident we would get him through the operation safely so the benefits appeared to outweigh the risks in this case. Below you can see the pictures of him before, during and after the procedure. I’m happy to say he came back today and his mouth is healing fine. Hopefully we have resolved his problem for the long term, although there is a small chance the sockets can occasionally regrow an entire new tooth. You will see in the photos one of the teeth cracked as it was very brittle and unfortunately some of the root was left behind, so we will remove this one at a later date when it protrudes from the gum line.

BEWARE: If you are squeamish one or two of the photos do show blood so don’t scroll down if you are sensitive to such images.

Before

Here’s Jack awaiting his operation, proudly showing off his ‘tusk’. We anaesthetised him using an injectable combination of drugs so that we had free access to his mouth and didn’t require an endotracheal tube.

Overgrown Incisor

Incisor lateral view

Massively overgrown lower incisors.

Lower incisors removed

Having removed his lower incisors with specialist rabbit dental equipment, the crooked upper incisors now needed to be removed to prevent them overgrowing. Rabbits actually have 6 incisor teeth, not four as most people assume. Behind the upper pair of incisors are a small pair of peg teeth against which the lower incisors shear and wear in rabbits with normal dental alignment.

Incisors extracted

Here are the 6 incisors after extraction. You can appreciate how long and curved the roots are compared to the crown, which makes it a technically difficult operation to extract them. Unfortunately the top incisor on the right hand side in this photo was very brittle and cracked both at the crown whilst gripping it and at the root during extraction. It is in two fragments in this photo. This one will undoubtedly grow back and have to be removed again in full at a later date.

 

 

 

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