If you are reading this blog post, then you probably already know that capybaras are the world’s largest rodent. Most of you know that rodent teeth keep growing, and that’s one reason why they chew everything up: they are keeping their teeth sharp. Even the molars keep growing, though everyone seems to forget about rodent molars. It’s the incisors, those big upper and lower front teeth, that remind us that we are looking at a rodent.

Baby Gidget: everything but the teeth

If humans lose a baby tooth, an adult tooth grows in to replace it. If humans lose an adult tooth, we’re done: it doesn’t grow back. We have to get a pretend tooth to fill the gap. So if rodents lose a tooth, it’s no big deal, is it? They just grow back. Well, yes and no. Dobby broke his upper incisors, and they grew back, right? Sometimes, things go terribly wrong. Rodents (and rabbits) can get overgrown teeth that poke into their gums and get in the way of eating. Usually they can be trimmed and eventually they may straighten out. But I am talking about terribly wrong, like if the upper incisors refuse to grow pretty and curved, and just make crazy shapes and don’t poke out of the gums in a predictable way. That’s what happened to our friend Gidget.

Dobby shows off his formidable chompers.

Compare Dobby’s fractured, but robust teeth with Gidget’s funky shaped teeth:

Dobby’s upper incisors show up like a uniform, solid curve. The lower incisors line up with the uppers at the cutting surface.

Gidget’s upper incisors show as a conglomerate of wiggly lines above the palate. Her lower incisors have grown too far, there being no uppers to meet and sharpen them.

Rodents have a “tooth bud” from which the tooth forms and grows. Capybaras are born with eyes open, fur, and teeth (like guinea pigs) so they are ready to graze with the herd. The teeth should grow out of the tooth bud with a uniform curve. The enamel is harder at the front (the tooth you can see), softer enamel behind (behind the tooth, in the mouth), so that the upper and lower incisors sharpen each other to razors with each bite. Gidget’s lower incisors are overgrown, but relatively normal. Her uppers look oddly misshapen, like noodles. There was no way for the upper and lowers to work together like scissors for cutting grass.

Gidget is a typical spoiled pet capybara, enjoying a leisurely bath.

We waited and waited, but it soon became clear that the upper incisors were never going to form correctly. And without the uppers, the lowers would eventually cut into her upper palate, unless she had regular tooth trimming. This would have to be done under anesthesia each time, can you see the dollar signs start to glow and chant voodoo spells to the accompaniment of drums along the Amazon? Gidget would have to have both upper and lower incisors removed. It was going to be very expensive, even if her owner could find a veterinarian willing to perform exotic dental extractions.

Gidget the capybara, looking perky after her surgery.

Rodents who have had their incisors removed do surprisingly well, especially when they have attentive owners. She should be fine and her recovery is going well. I started a Go Fund Me to help with Gidget’s veterinary bills. I will write up her procedure for the ROUS Foundation with more technical photos. The ROUS Foundation will follow her case, but unfortunately, we will probably never know why her teeth didn’t form correctly. It doesn’t seem to be diet-related or the result of any kind of typical vitamin deficiency. This kind of anomaly can happen with any kind of pet, but veterinarians who will treat capybaras are rare. Responsible pet ownership can be an expensive proposition.