The schematic representation on the
left shows that the upper and lower incisors match properly but the length
of individual molars varies greatly creating a bite which resembles a wave.
Because of the uneven bite the feed moves much less efficiently up towards
the back of the mouth as it is being chewed. That is the reason horses
with this condition eat more slowly than other horses. Weight loss
can also be a factor. Wavemouth can be caused by retained caps (milk
teeth) at a young age and is subsequently made worse by the development
of overbite. Wavemouth is also
frequently caused or aggrevated by badly distributed excessive filing of
the molars. Filing is quite a delicate operation and needs to be done accurately.
The illustration shows one example of wavemouth; there are many variations
of this abnormality.