Q: My friend has been told by a retired vet that her mare might have wave mouth. What is this, and is it serious?
A: First, let me describe a wave mouth. A horse has 24 cheek teeth in total that run in rows of six - six in the upper jaw, both sides, and six in the lower jaw, both sides. These rows of six teeth are also called the ‘arcades’, and although they consist of six separate teeth, they are used as one large grinding surface. The arcades should run level from front to back, with a slight natural angle, so that when you look in the mouth, the inner edge of the lower teeth sits slightly higher than the outer edge, and visa versa in the upper arcades. In a wave mouth, if you feel the teeth from front to back, instead of the regular angle, they are like a roller coaster, with a series of convex and concave changes, hence the name 'wave'. A wave mouth can develop for a number of reasons, such as the size and shape of the horse’s head, missing teeth or impacted teeth, and often leads to an inefficient grinding surface within the mouth, preventing the horse from eating correctly.
In the case of your friend's mare, the desired outcome is to correct the wave, rebalancing the horse's mouth by reducing the high areas of teeth within it. However, certain factors should be taken into account before any action is taken. If the mare is an older horse and managing to eat well, to reduce the wave completely may be taking away valuable tooth crown and therefore the grinding surface that may already be running out. In this instance, it may be wiser to correct the wave gradually over time to see how her mouth adjusts. The severity of the wave - that is how much the teeth differ from a normal, even mouth - can also effect the treatment. A very severe wave mouth that prevents a horse from eating and is, in effect, blocking the natural grinding action of the mouth, must be corrected to allow the horse to use its teeth in the correct manner and start eating again.
My advice to your friend would be to have her mare’s teeth checked again and work out the best method of correction. A slight wave mouth now could lead to abnormal wear on her teeth and far greater problems further down the line.