​Look At Their Teeth

By Gaye DeRusso
 
Looking at horse’s teeth to figure out the age can be very intimidating. First because you have to open their mouth and then usually grab their tongue so you can keep it open long enough to  see all those teeth. You need to look at many things, not just one thing to determine their age. So, it is not just a quick look. You need to look at the size, length and angle of the teeth, the shape, Galvayne's Groove, color, cups, stars, and hooks. Then also know that if the horse was stall bound and fed hay, they usually look younger and if grazing on sandy surfaces, they may appear older due to wear. Then make your estimate. This takes some time to do it well, so if see someone just look at the groove and tell you it’s age, know that you need to check yourself to get a better estimate. 
 
It  is a good idea to look at your own  horse's teeth every once in a while, even if you know its age. Sometimes they get things like bark or sticks and even rocks stuck in between their teeth or even in the roof of their mouth. Sometimes the hay will have fox tails in it and those can get stuck in between teeth and their gums. You also want to make sure your horse has a healthy mouth, as they get older, some will get loose teeth, or crack a tooth and some will get a dental disease called EOTRH (Equine Odontoclastic Tooth Resorption and Hypercementosis). It  is a syndrome in older horses resulting in disease and destruction of incisors and canine teeth. The roots of the teeth begin to be resorbed and the body can start to buildup calcified tissue on the roots of the teeth. It is a painful condition, and the horse may need teeth pulled so best to know early on or if you are buying a horse. So, when looking at their teeth also pull up the lips and look above and below the tooth to see the condition of the gums and if they are starting to get EOTRH. 
 
When I look at horses to buy, I always open their mouth and look at their teeth and I can tell you it’s not always pretty in there because some horses have never had their teeth done, some are missing teeth, some have foreign objects in there and some have EOTRH. So best to know what you’re dealing with. 
 
Not all vets are good at aging a horse from teeth. The honest ones will tell you that. There are so many things to look at and consider when aging from the teeth. Shape, length, size, angle, color, wear, galvanized groove, hooks, cups, and stars. So even though we like to think vets are great at it, not all of them are and it’s a skill that needs to be acquired. The more they age horses the better they get, the less they have aged horses,  or  they do not  do it often they will not be as  good. 
 
I did a test to  one vet one year to prove it to my clients. I pulled out the same horse 3 different times he came to look at other horses. He gave me 3 totally different ages and I looked at my clients, like I told you so. 
 
So, if you really need to age  horses it is best to learn yourself and then if needed, find a vet who does it a lot and if you want to test yourself or them, age some horses with papers to see if you and your vet are close to what is true. 
 
Oh, and before I forget Papers!! I can't tell you how many horses I have seen with papers that are not that horse. In fact, I saw one on Facebook headed to Europe and she wanted to ask about the breeding lines. The papers said the horse had a blaze, and the horse was completely black no blaze that she had bought. So, check your papers and make sure they match your horse. If it says socks and your horse has none of course they are not his papers. So just because you’re buying a horse with papers does not mean they are their papers.
 
Ok so let’s just cover some basic simple rules to help guide  you on teeth aging. And you must take them all into account not just one thing. You look at it all and then put the findings together to get the estimate of age. 
 
Most horses will have all their permanent teeth by age 5.
 
It is easy to tell a younger horse's age but gets harder as they get closer to 15. 
 
Horse’s teeth that graze vs being stalled will appear older due to the wear. Horses that graze on grass with sandy ground will wear their teeth flatter.
 
Canine teeth erupt between 4-6 years old but mostly in geldings and stallions, mares rarely have them. So, if no canine teeth, the horse is usually under 6 but if it has canine then it is 4 years or up. 
 
Angle of the teeth
 
Younger horses  have more upright teeth, like our teeth and older horses have more angled teeth like a bird’s beak. So, if teeth are upright, it is usually a young horse, if they are starting to angle then usually about 10-12 and if a lot of angle closer to 20. 
 
Color
 
As horses get older their teeth can get darker and or yellow. So, if the horse’s teeth are angled and yellow closer to 20. 
 
Length
 
Young horses have shorter teeth, older horses will have longer teeth. So long in the tooth as they say means closer to 15 and up.
 
Galvayne's Groove 
 
This is on the outer incisor. It is a dark line that comes down the tooth as the horse ages. Starts at 10, so you will see a small mark. When it's half way down the horse is close to  15. When the line is all the way down the tooth the horse is close to  20. The top of the line disappears at 25, so nothing at top but there will be a line half way down to the bottom. At 30 the line is usually gone or almost gone. Look at both sides of the horses outside incisor as they may not be the same and take an average.
 
Age 10
At top   
                                    
Age 15                                     
Half way down
 
Age 20 
All the way down
 
Age  25
Disappears at top, starts half way down to the  bottom
 
Age 30 
Disappears 
                  
 
Shape
 
The oval to round shape - age of five to nine. Round to triangular shape - age range of 10-15 and triangular to rectangular 16-20 age range.
 
Oval to round - 5-9
 
Round - 10-14
 
Triangle -15
 
Rectangle-20
 
Cups
 
This is on the grinding surface of the tooth and appears as an indented area with a dark center in the middle of each tooth. The cups appear in the permanent teeth, so a horse will have them around age 5 and the cups will disappear as they get older. They disappear from the bottom central incisors at 6, the intermediates at 7  and corners at 8. So, they start to disappear from the lower front teeth, then the teeth right next to those and then the ones more on the sides.
 
The top incisors lose their cups after the bottom teeth. So don't forget to look at the top teeth. So central  top teeth lose the cups at 9, then the top intermediate teeth at 10 and then the corners at 11. So, they disappear from the 2 front upper teeth at 9, then the teeth next to those at 10 and the ones on the side at 11.
 
So, by age 12 or older all the cups are gone and when you open the mouth you will not see any cups, but you will see stars.
 
Stars
This is a yellowish spot that appears more toward the front of the teeth so toward the lips. The stars over time will move  toward the middle of the tooth. They start as a rectangular appearance and then turn round and move toward the middle of the tooth as the horse gets older. It appears in the central (front ) incisors at 8, the intermediates at 9 and corners at 10. 
 
Hook
There’s a hook that can form at the rear of the top corner incisor, which can also help in telling age. It appears around age 7 and disappears around age 9. It will then reappear at age 11 and may stay through the mid-teens.
 
In conclusion remember there are many things to look at not just one. You may have to look at one thing at a time and write it down and then add it all together to get the best estimate of age. Some vets, trainers and owners are great at aging horses and others are not. It is a skill, and it can be a fun skill to acquire.