The other week I was able to snap a couple of pictures of some dental pathology found on dental float. As mentioned before, the equine tooth is designed to grind and wear down overtime. This natural process works very well and allows them to chew roughage like grass and hay for many years. I could go on and on about the incredible design of the equine tooth, but today I would just like to highlight what happens when abnormalities are present in the mouth. Just like anything in life, no system is perfect and no individual is perfect. These tiny imperfections in the way a horse chews or how their teeth are aligned compound over time and can lead to large abnormalities that affect not just their ability to chew, but can also cause discomfort. This is beyond the "sharp points" that will inevitably develop in all horses, due to the natural design of the mouth. In the first image you will see what we refer to as a "hook". This hook is in the "rostral" or front part of the mouth on the 2nd premolar. The 1st premolar would be referred to as the "wolf tooth" and is not present in this horse. Not all horses have a wolf tooth, and those that do, often have them extracted due to their lack of function and potential to cause discomfort in horses who wear a bit and bridle. This large hook seen in this image forms due to the top row of teeth being set a little bit further forward than the lower row of teeth. Because the lower row of teeth does not wear against the full surface of the upper tooth, a large portion of the tooth up front becomes longer than the rest of the premolar. In some instances this can become extreme to the point it contacts the opposing gum line. The size of this hook likely developed over several years without dental care. As you can imagine if the top row of teeth is set further forward than the lower row, then the lower row will have the same issue with the tooth in the back. This was the case in this horse that it had a large hook in the back on the lower row as well. When floating down large abnormalities, care is taken by the veterinarian to take the tooth down at an appropriate degree. Just as these abnormalities are not formed overnight, they often cannot be fixed overnight. The equine tooth has multiple pulp chambers, which if become exposed from excessive floating, will cause the horse discomfort and potentially compromise the health of the tooth. If the overgrown portion of the tooth contains a pulp chamber, only about 3mm can be floated off at a time. Some horses may need floated every 6 months to take down the abnormality gradually and get ahead of the process causing abnormal wear. This is also another good reason to have regular scheduled dental care so that such large abnormalities do not get a chance to form.
The 2nd image shows a missing tooth between the 2nd and 4th premolars. You can tell that the loss of this tooth was not recent because the 2nd and 4th premolars have migrated closer together. Also, if you could see the lower row of teeth you would see that the 2nd premolar on the lower jaw was mildly overgrown due to lack of wear from having no opposing premolar. This is an older horse who was last floated about 10 months ago. This horse is also missing its first molar on the lower row of teeth which has led to the overgrowth or "step" of the opposing upper 1st molar. Because this horse has known missing teeth and dental problems he will always have abnormal wear in his mouth and needs at minimum yearly dental floating, and potentially floating every 6 months so that the teeth with no opposing molar or premolar can be kept in check at small increments. Another problem which is hard to visualize in this photo, is that the last molar is worn to the gum line. This is an older horse and the last molar has reached the end of functional "crown" (or tooth above the gum line), and the 2nd to last molar is also shortening and running out of crown. Horses have a large tooth which slowly "erupts" from the gum line overtime. They don't continually "grow" teeth. When that tooth has worn down, there is no more tooth to give. Horses can and will run out of tooth if they live long enough. Due to the large amount of pathology in this older horse's mouth, managing his diet and regular dental care is going to be a very important part of keeping him healthy.
