EQUUS CONSULTANTS

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Theories range from “waking up” a body by taking in more oxygen or cooling off the brain in a warm environment. Yawning has been observed in nearly all vertebrates, included fish and birds, but is more likely be seen in dogs and horses.

When yawning is a sign of fatigue When yawning is a sign of fatigue in horses, it is usually accompanied by other signs, such as listlessness or dozing. A horse who is yawning but is otherwise alert may be doing so for other reasons.

Yawning can be a stress response. Although it hasn't been studied specifically in horses, the stress-yawn is a well-documented phenomenon in dogs. It's not the sort of stress that requires a call to the veterinarian, however, but more a low-level everyday matter. For instance, a horse may yawn before being tacked up in anticipation of work or after a ride in an "I'm glad that's over" sort of way. Some horses yawn immediately after being

loaded into a trailer and others yawn while waiting to be turned out. There is a theory that yawning facilitates a shift between emotional states and the sympathetic and parasympathetic nervous system.

Yawning is contagious (you may even be yawning while reading this), and horses probably yawn in response to seeing other horses, or even humans, yawn. Research in dogs found they were more likely to mimic yawns of their owner than a stranger, suggesting it was an empathetic and emotional reaction.

Finally, yawning is sometimes a sign of trouble. Sores or injuries in a horse’s mouth can cause him to yawn. Repetitive yawning can be a sign of liver disease in humans and horses, but this is very rare. If you’re worried about why your horse is yawning, do a quick check of his vital signs and overall demeanor and check in with your veterinarian.

Yawning has been observed in nearly all vertebrates, including fish and birds.