by Charlene Strickland
Equine dentistry is a specialized area, but one with which all horse owners should be acquainted as your horse’s teeth affect his well-being, both in ingesting food and responding to the pressure of a halter or bit.
First, let’s discuss the basic anatomy and development of the teeth. Like humans, horses first have baby, or deciduous teeth. Permanent teeth replace these temporary ones at specific ages.
Throughout the horse’s life, teeth grow to counteract the continual wear through thousands of hours of grinding feed. In fact, horse’s teeth continue to erupt into the animal’s 20s.
You’re familiar with your horse’s front teeth, or incisors. As an adult, he has 12 of these: six on the upper jaw and six on the lower jaw. Behind the incisors are gums with no teeth, with the lower gums called the bars of the mouth.
Behind the bars and in the horse’s jaw are at least 24 cheek teeth, including 12 premolars and 12 molars. On the upper jaw, he has three of each on each side, matched on the lower jaw. With these teeth, hidden in the dark back of the horse’s mouth, the horse chews grass, hay, and grain.
The horse may have two to four additional first premolars, called the wolf teeth. Because these may cause problems when a bit pulls tissue against the tooth, these are usually extracted.
Excluding wolf teeth, the horse will have 36 teeth. A male horse, stallion, or gelding, also grows four canines. These pointed, conical teeth erupt behind the incisors.
The young horse develops permanent teeth up through the age of five. Often, this eruption of teeth changes a horse’s behaviour, which trainers notice during the animal’s schooling sessions.
“The young horse could have 16 teeth coming in at once, and we often ask the two- or three-year-old to do a lot at that time,” says Dr. Leon Scrutchfield, of Texas A & M University. “Therefore, it’s not unforeseen that the animal can have trouble eating and with performance.”
Even if a young horse doesn’t show teething pains, he might have caps says Scrutchfield. A cap is a deciduous tooth that doesn’t fall off as the permanent one erupts.
“A cap has a flat, level surface, and is much different from a permanent tooth. Most caps come off on their own, but some have long root spicules. When that root spicule comes off, it sticks the horse in the gum.”
Horses rarely suffer from tooth decay. However, a horse aged two or older will develop sharp points on the sides of his cheek teeth. “The horse will grind his teeth by moving the lower jaw laterally,” says Scrutchfield.
“The upper arcades (chewing surfaces) are much wider apart than the lower arcades. He never quite wipes out these sharp points that develop on the inside of the bottom teeth with the outsides of the upper teeth.”
These sharp enamel points can irritate the tongue and the insides of the cheeks, even causing ulcers in the cheeks.
“They can look like daggers,” says Scrutchfield. “Anything over the horse’s nose will push the cheek into the points – even pulling him around with a halter can cause the horse some misery.”
The horse can develop points on both upper and lower cheek teeth. Some horsemen believe that only older horses develop points, but Scrutchfield points out that two-year-olds can have problems too.
Floating the Teeth
Floating the teeth (also called rasping or grinding) smooths the points so the teeth are smooth and level. Examining the teeth, your veterinarian or dental practitioner may first smooth the sharp edges of the canines of a male horse. These teeth grow taller as the horse ages, and horses can snag them on fences. They also tend to accumulate tartar.
When floating, Scrutchfield first shapes the canines short and blunt to avoid problems, and also for safer dental work on the cheek teeth.
He then floats the teeth of the upper arcade, rounding and polishing the tops and sides of the teeth. As in any sanding task, this involves first a file with a rougher abrasive surface, then a smoother file for the polishing.
Watch your veterinarian perform this task. He’ll insert the file into the horse’s open mouth, and slide it forward and back. He has to exert a certain amount of pressure to smooth the points, while peering into the darkness of the interior of the horse’s mouth.
In the horse’s jaws, each upper tooth opposes its lower counterpart. A missing tooth or retained cap affects how the horse chews. A youngster that loses a baby tooth due to injury may not develop normal permanent teeth, as each tooth has to push against its mate.
Teeth that aren’t in occlusion (meeting) continue to grow taller in the mouth. Your equine practitioner will have to grind this tooth regularly, or it can grow so tall that it presses into the gum.
Jaw alignment also often creates dental disorders, says Scrutchfield. For example, a horse with a slight overbite won’t wear tooth surfaces level.
“For him to slide his jaw laterally to grind feed, he has to open his mouth a little. That will separate the cheek teeth when he drops his lower jaw down. With the teeth cut off level and smooth, he can slide his lower jaw either direction without separating the back cheek teeth.”
The horse with a parrot mouth also requires regular dental treatment. Here, the upper incisors grow long, not hitting the lower. This also forces the animal to open its mouth to use its jaw laterally. The practitioner’s job is to shorten the incisors, both upper and lower, to help the horse chew more efficiently.
Routine Checks & Exam Prep
Scrutchfield advises owners to check their horse’s teeth occlusion on a regular basis. Move the lower jaw laterally, and listen for grinding sounds.
You can also look straight on. As you move the lower jaw, the angle on the table surface of the cheek teeth should separate the incisors after about a half-tooth movement.
During dental procedures, the horse must cooperate; he must stand still and not move his head or bite the practitioner. Some veterinarians use a mouth speculum, a device that holds the jaws apart. Others apply a twitch, a common restraint for medical treatments.
You can help prepare your horse for dental care. Train him to accept your examining his teeth. Many horses seem to enjoy the sensation of your rubbing your finger across their gums, above the top incisors.
You can also feel the cheek teeth for points. Slide your finger into the corner of the mouth and feel the sides of the teeth. Keep your finger along the cheek, not between the upper and lower rows of teeth. You might hold the tongue to one side with your other hand, to prevent the horse from biting.
Just as with humans, regular dental examinations are a must for equines and can add up to three to five years to your horse’s life. Problems with riding and feeding can all be related to trouble with horses’ teeth. And, in the end, it’s always easier to prevent – rather than correct – problems through routine examinations and procedures.
