The normal parotid salivary glands are large, lumpy-feeling glands that lie right behind the jaw bones, in a vertical line from the base of the ear to the jugular groove.
In grazing horses, these glands may become obviously enlarged, a condition known as parotiditis. This is thought to be an allergic response to an allergen (probably pollens) at pasture.
When horses are taken off pasture, the swelling decreases. Usually, horses with parotiditis are normal otherwise. The swelling of the glands does not seem painful or bothersome. In some cases, the veins of the face may stand out or bulge. This is caused by the swollen parotid glands that press on the jugular and its tributary veins, damming the blood back up into the face.
Other Diagnoses Considered
Treatments May Include
Prognosis & Relevant Factors
Prognosis is good and, in many cases, horses can be returned to pasture later without recurrence.
I Might ObserveRelated Observations
QUESTIONS TO ASK MY VET