An adult male horse has 44 permanent teeth and a mare between 36 and 40. Until they are about 5 years old they will be on their first set of teeth, known as their deciduous teeth, by 5 they should have their permanent adult teeth in.

About 18 million years ago the teeth in fossilised skeletons of horses changed as they adapted to an abrasive diet. The surface of the molars changed becoming more complex and better suited for chewing grasses and other tough plants. Their teeth also began to grow taller, laying the evolution for the modern horse’s teeth.

Constantly growing?

We often say that horse’s teeth grow constantly. However horse’s teeth have finished growing once their permanent teeth are in place, but they are around 12cm long and gradually erupt from the gums, around 0.3cm per year. Their abrasive diet means that their teeth wear down gradually over time, and so this eruption means that their teeth do not wear down completely until they are much older. The problems are that the constant wear on the upper surface of the teeth can lead to sharp edges and uneven wear, which can lead to a whole host of issues.

Problems that may stem from dental issues and signs to look out for

• Dropping food out of their mouth when they’re eating
• Difficulty in chewing or excess salivation
• Losing weight, or just poor general condition
• Undigested food in their manure
• Resisting the bit, head tossing, bit chewing, or anything that makes you think that they are uncomfortable with the bit in their mouth.
• Really badly smelling breath
• Swelling anywhere around their face and mouth
• Discharge from the nose,
• Traces of blood in their mouth
• Any major change in behaviour that makes it seem like they’re in pain.

Even if your horse is showing no symptoms of discomfort some learn to live with a degree of pain, so it’s worth getting a regular check up on their teeth.

Poor teeth means poor diet and a poor diet can lead to all of the above and digestive disorders such as colic.

Does being at pasture make a difference?

Short answer, yes. The longer answer means looking at the evolution of the horse and how they have adapted to nature. A horse at pasture will use the incisors to tear at the grass and the molars to grind it down. In a field of pasture there will be soft bits and places where the grass grows a bit tougher, there may even be a tasty shrub or two that they have a chew on. This full range of jaw movement and different wearing means that the teeth are more inclined to wear evenly. Added to this that a grazing diet normally needs a whole lot more chewing that a pellet or cubed diet and you can see why horses out in the pasture tend to have fewer problems. In fact that a pellet or cube diet can actively inhibit the normal chewing pattern, and can lead to problems with their teeth and jaws.

Some specific dental problems

• Dental caps; retained deciduous teeth after their permanent teeth have erupted.
• Molar hook; A result of a misaligned upper and lower jaw, so that the upper jaw lies ahead of the lower jaw. Meaning the 2nd molar of the upper jaw and the rear portion of the last molar on the lower jaw don’t have an opposing surface to wear against. The uneven wear as the tooth continues to erupt can form hooks.
• Parrot mouth; this congenital condition means the upper jaw is longer than the lower jaw meaning hooks can develop on the upper and lower molar teeth.
• Abnormality due to lack of wear, leading to the teeth needing to be shortened and smoothed.
• Broken teeth, gum infections, dental infections,
• Enamel points; these develop on the outer edges of upper molars and inner edges of the lower molars. This happens when there is an incomplete overlap of the upper and lower molars and uneven wear on the grinding or biting surfaces during side to side chewing.

What will the dentist do?

A good dentist should give your horse a once over to make sure that your horse is healthy and sound. As the list above shows poor teeth will lead to a whole host of other conditions. After this the visit may follow along these sort of line.

1. Checking the face for swellings or obvious problems.
2. Manipulating the jaw to check it will move front back and side to side with a free range of movement.
3. Floating the first two premolars, that can be with or without the gag to hold open the horse’s mouth. Some nervous horses may find having the first work done without the gag is more soothing.
4. The dentist will go on to float the other teeth to provide an even surface for them to chew it is probable that they will give the horse breaks every 5 minutes or so.
5. Incisor alignment to ensure that the angle between the incisors is correct and the horse has the correct range of movement.

Do I need to do anything before the visit?

Most horses only have hands near their mouths if they are getting a treat or the bit in their mouth. You might need to get them used to the idea that people will be handling them around their mouth, start by touching the front of their nose. Do they try and nibble or chew your hand looking for a treat. Try and work with them so you can touch their lips without them reaching to chew or lick you.

Older horses and their teeth

Sadly since the horse’s teeth don’t carry on growing, rather they erupt, meaning that eventually there is no more teeth left to erupt. Older horses are more likely to develop hooks on their teeth and prone to a condition known as choke, where they literally choke or gag on their food due to poorly chewed food. This poor chewing can also lead to colic and laminitis, for older horses checks up are more vital than ever.

But the end of their teeth doesn’t have to mean the end of their life as they would in the wild, different diets and specialist senior food can help them in their twilight years.

There is an old saying, ‘No feet, no horses.’ Well what’s true for the feet is true for the teeth, and as with their feet regular checks and specialist care can leave your horse pain free for a long and happy life.