Veterinary Dentistry: Auckland Zoo
Meet Itika. She’s a lovely zebra at the Auckland Zoo. Like the more common horse, zebras are browsers and grazers and have hypsodont dentition.
Hypsodont species, including most grazers, grind their teeth down against their opposing teeth on the rough feed and grit they pick up with it, but their teeth are designed for that. Their teeth, once the roots develop, continue to erupt until the animal runs out of tooth…for a horse, that’s somewhere in their 30’s.
Horses, in particular, have been bred for thousands of years for things other than good teeth. Because of this, we've selected genetically for horses with suboptimal bites, and consequently, we must help them by performing odontoplasty, or “floating their teeth.”
Their teeth should be checked at least every year, under normal circumstances.
“Floating” includes removal of sharp enamel points by grinding, either by hand or with special motorised floats, preferably with constant water irrigation, like your dentist would use.
The edges and teeth most commonly floated include the outsides of the top (maxillary) teeth and the inside on the lower (mandibular) teeth to prevent or correct “malocclusions”, or abnormal bites, which usually allow the formation of sharp overgrowths which cut into the equid's cheeks or tongue.
Thankfully, zebras have had natural selection to weed out those with poor occlusion. For example, those zebras which couldn't chew properly didn't get enough nutrition, therefore they weren't as healthy as their mates and couldn't run as fast from predators…and thus didn't live to reproduce.
Result: better teeth in the gene pool of zebras overall.
Itika, as an aging zebra, needed some special dentistry and I was fortunate to be asked to work with her and her amazing crew of veterinarians, veterinary students and zookeepers. Everyone knew what their role was and it went like clockwork. Fantastic. She was up and around before she knew it.
Zebras at many zoos are left “wild” as much as possible, and are not tame enough to be haltered and treated like a horse, so they need a general anaesthesia for any hands-on treatment.
We minimise the time these animals must be down under anaesthesia for their safety. Here you see Itika propped up on her chest with hay bales to assist her breathing and comfort.
The towel taped over her eyes is to prevent visual stimuli from startling her and waking her up until we are finished, and she is recovered sufficiently from her anaesthesia to safely stand.
The aluminium mouth speculum helps keep her mouth open and lets me see, with the help of my head lamp and flushing the mouth before we get in there, what pathology I can find to help repair. After that, it helps keep my arms from being broken if she chews!
Fantastic crew at the zoo!
Thank you to Vanessa Marsh for taking these lovely photos and to Kate Orgias for allowing me to post these photos of Itika and the crew. Thank you to Nathalie and her fantastic crew of zookeepers at Auckland Zoo Pridelands for your awesome help and friendly smiles.
Go see these lovely animals at the zoo, everyone!