horse lost baby tooth
Q. My long yearling Dutch Warmblood mare knocked her tooth out so severely that it had to be removed by my vet. We’re not sure how she did it but I thought that, since it’s a baby tooth, it would be fine (like the kindergartner who knocks out a front tooth and just needs to wait for the adult tooth to grow in). However, I’m coming to understand that it might be different for horses. What is the long-term prognosis for a young horse losing a tooth prematurely?

—Laura, Seattle, Washington

A. The traumatic, premature loss of a deciduous incisor (or “baby tooth” as you’ve referred to it) can be problematic in any species and, in fact, may be urgent in horses. Missing teeth in horses generally lead to malocclusions (misaligned bite) or pathologic (disease-causing), but functioning, occlusal (chewing) patterns. Fracture of the incisive bone (the part of the upper jaw adjacent to the incisors) and incisive portion of the mandible (lower jaw) is the most common fracture of the horse’s skull, and I see it mostly in “mouthy” colts and less often in fillies.

In the case of your filly, the deciduous mandibular central incisor tooth probably dislocated from the surrounding alveolar bone, or tooth socket, when your filly put her teeth on a hard object and pulled back. The bony tooth socket most likely broke outward, toward the lip. Because horses usually shed this baby tooth when the permanent central incisor erupts at 2 1/2 years (30 months), the root was most likely becoming very thin and also broke when the accident occurred. Your veterinarian chose to extract the tooth for this reason, so as not to allow an infection to develop. What remains to be seen is whether the developing permanent tooth bud, which is near the baby tooth, was also damaged. Hopefully it was not, and the tooth will develop and erupt normally. At the very least, I would expect the permanent tooth to erupt a bit prematurely and asynchronously (not at the same time) from the adjacent permanent central incisor due to the lack of a baby tooth in the permanent tooth’s eruption tunnel.

Crowding may occur should the baby teeth on either side of the missing tooth drift toward the midline. In this case, your veterinarian can perform careful odontoplasty to remove any dental tissue impeding the permanent incisor’s eruption. The occluding tooth in the maxillary dentition will also require attention, as it will erupt unimpeded downward into the void of the missing baby tooth.

Your veterinarian will need to take periodic radiographs to assess the developing permanent tooth prior to its scheduled eruption. If the tooth bud was damaged, the developing permanent tooth will either never develop or develop in a misshapen way. It may even form a cyst within the bone that may expand and damage adjacent teeth. The radiographs above demonstrate the problematic, incomplete, misshapen development of a tooth in a case such as yours.

Serial radiography will help your veterinarian decide how to best use interventional dental procedures to help this filly attain the most normal, functioning dentition possible.