STUD FARM DIARIES

It started out as a roughened patch along the outside of the mare’s ear. It was originally thought to be fly or gnat irritation. Gnats, especially, love to gather on the ears of the horses in pasture and bite them along the ear’s edge. However, after a while, a white, thickened plaque began spreading out from the edge. It was just a flat, sort of warty-appearing area without hair. Soon it became a swelling in the ear. Could it be that the swelling was a result of the mare rubbing her irritated ear? Could be. But the more probable culprit was a sarcoid tumor.

Whenever anyone uses the word “tumor” people start to get excited. However sarcoid tumors are rarely life-threatening and are the most common tumor found in horses. A study published in 1998 suggested that Arabians, Quarter Horses, and Appaloosas were more likely to develop sarcoids than either Thoroughbreds or Standardbreds.

There are various forms of sarcoid tumors and they are thought to be caused by a bovine (cattle) papilloma virus. The virus, BPV, Types 1 and 2, have also been found in several fly species,