Most pet owners are familiar with the dental cleaning recommendations for their pets. Taking a dog or cat to the vet for a "dental" is so much like what humans go through, apart from the general anesthesia, that even the tools used are similar: the scaler, the polisher, and even the radiographic equipment are all virtually identical to what is hanging in the human dentist’s office. Dogs and cats can even get root canals! But what about our larger animal friends? Who brushes your horse’s teeth?
In the horse world, dental care is a world apart from what goes on in the small animal clinic. For horses, dental care focuses on filing their teeth, not cleaning them. The reason for this lies in the nature of the horse itself. Being herbivores, horses (and other grazing animals like cattle and goats) are hypsodonts, meaning they have teeth with a lot of crown that continually grows to make up for the constant wear when grazing. This is in contrast to brachydonts, like humans, dogs, and cats, whose teeth do not undergo nearly the amount of grinding and therefore do not continually grow over their lifespan. It is also this continuous growth that makes it a fairly simple task to roughly estimate a horse’s age by his teeth.
As an anatomical rule, a horse’s upper jaw (maxilla) is slightly wider than his lower jaw (mandible). As the horse ages and his teeth continue to grow, the outside edges of the molars in the maxilla begin to grow sharp edges, as do the inside edges of the molars in the mandible. These edges inevitably lead to open sores in the mouth that never get a chance to heal.
Sometimes, if an older horse loses a back molar, the unopposed molar on the opposite jaw will grow like crazy because it has nothing to grind against. Every once in a while you’ll open an older horse’s mouth and it’s like a mountain range in there, with a Mt. Everest molar in the back poking gnarly holes all over the place. This is the reason one of the top recommendations to making sure your older horse is healthy is regular dental checks. Bad teeth are the number one reason older horses have trouble keeping on weight, especially in the winter.
The act of filing down these pointy edges is called floating, and the rasps used are called floats. To find out about a horse’s dental history, your doctor would normally ask, "When was the last time your horse was floated?" Although this sounds like an attempt to ford your horse across the Mississippi River, it actually refers to a routine veterinary procedure!
So how do we float horse teeth? Two words: proper sedation. There are wonderful tranquilizers on the market now that are safe and easy to use (especially for short, weakling vets like me) to subdue a one thousand pound animal. This sedation will not make the horse lie down, but rather stand still (albeit wobbly) and usually allow his mouth to be held open with a demonic-looking device called a mouth speculum while the vet takes a good look around and then begins to file down any sharp edges (called "points") that she finds.
There are two types of dental floats used in practice: the hand float and the power float. The hand float is the traditional rasp that is drawn against the offending tooth by pure muscle-power alone (click here to see the hand float). As you might imagine, this is tough work. The power float is much more awesome (click here to see the power float). Muscle-power is replaced by an electric power tool that makes a disc-shaped rasp spin and do the work for you.
The goal of floating is not to smooth out a horse’s teeth. The tooth’s irregular surface is required for the efficient grinding of roughage, such as grass and hay. Floating is only used to file off the sharp points in order to prevent damage to the soft tissue of the cheeks and tongue.
Due to the nature of the horse’s diet, we usually don’t worry about gingivitis and periodontal disease, like we do with dogs, cats, and humans. One of the nice things about being an herbivore!