A sore mouth stopped Bunter from eating
Bunter the three year old rabbit had stopped eating. He was normally an enthusiastic nibbler, chewing grass as he hopped around the lawn, and tucking hungrily into the bowl of rabbit muesli that his owner put out for him every morning.But suddenly, for no particular reason, his appetite evaporated. He still hopped around the garden, but he wasn't nibbling any more. He sat waiting for his breakfast bowl, but instead of tucking into it, he crouched beside it, just looking at the food.
His owner, Beth, brought him to see me straight away. This was such a radical change in behaviour that she knew there had to be something wrong with him. But what could it be? He was still bright eyed, active and strong. Why had he suddenly gone off his food?
As a vet, the first thing to do when presented with a sick animal is to listen to the owner's account of what's happened. After Beth had explained to me how Bunter was behaving, I already had a hint about what was probably going on with him. To be thorough, I checked him over physically, running my hands over his body, feeling for any lumps or sore areas, listening to his heart and lungs with a stethoscope, and taking his temperature. As I had expected, everything was normal, so I moved on to the part of the examination that I felt was most likely to give me an answer. I asked Beth to hold Bunter while used a special type of scope to look inside his mouth. I found exactly what I expected to find: Bunter had developed sharp spurs on the edges of his teeth, and these had scraped along the side of his tongue, causing a nasty laceration.
Dental disease is astonishingly common in rabbits, and it's probably the most common reason for healthy, bright, active rabbits to stop eating. There are three main reasons why it's so common.
First, pet rabbits live very different lives to their wild cousins. Wild rabbits spend most of their lives hopping around meadows and hillsides, chewing grass that's often in short supply. They spend so much time doing this that their teeth are almost continually active. This means that the teeth are continually been worn down, as the top teeth grind against the bottom teeth. Rabbit teeth continue to grow throughout the whole life of the rabbit, but the rate of wear is matched to the rate of growth, so they tend to stay at the ideal level. It's very different for pet rabbits like Bunter. While he does graze on grass, he gets extra calories from his rabbit muesli, so he doesn't depend completely on grazing, and he doesn't need to spend so much time doing it. This means that his teeth are not ground down as much as they ought to be. They grow too long, and then start to curve and distort.
The second problem is that pet rabbits have metabolic complications that result from the combination of too much food and not enough sunshine. This area is not fully understood, but calcium metabolism is a subtle balance between Vitamin D (produced by the body when exposed to sunshine) and calcium and phosphorus (consumed in the diet). When the balance goes out of kilter, the teeth start to grow crookedly.
The third reason for dental issues in rabbits is genetic: pet rabbits seem to have been bred to have a predisposition to developing crooked teeth that develop spurs. Again, this is an area that has not been properly investigated and explained.
The result of these three factors is that rabbits in early middle age, like Bunter, are very prone to dental disease caused by crooked teeth with sharp edges. The mouth is an interesting mix of hard objects (teeth) and soft tissues (gums, the tongue, and the lining of the mouth). It only "works" as long as the teeth stay in perfect alignment with one another. If the teeth are squint, they impinge on the soft structures, causing pain and injury.
The good news is that this is a problem that can be treated effectively. I had to give Bunter a short general anaesthetic, and I then used a long metal file to rub off the sharp protruding spurs of teeth. After doing this, I went on to file the edges of all of his teeth, so that by the time I'd finished, he had a perfectly lined-up set of dentition. I also had to give him pain relief: the laceration on his tongue would take a few days to settle down and it was sore.
I sent Beth home with a feeding syringe: Bunter wouldn't want to eat properly for a couple of days, but he needed nutrition to keep him going. Beth used the syringe to feed him a liquidised form rabbit food. She was able to avoid the sore part of his tongue as she gave it to him, and it was obvious that he was enjoying this special food. He pressed his mouth against the syringe, almost like a baby lamb suckling a bottle of milk. He had always been hungry, but the problem had been that when he chewed food, the sharp spur had been digging into his tongue. Now that this wasn't happening, he was able to enjoy the nutrition that he needed.
There is some bad news: rabbits like Bunter are almost certain to need repeated sessions of tooth filing. The sharp spurs come back after three or four months, and the edges of the crooked teeth need to be filed smooth again. With luck, he'll live into his old age, but only if he keeps coming back to see me, the rabbit dentist.