Echinococcus granulosus hydatid cysts in the livers of two horses.

This research focuses on the post-mortem examination of two horses, imported from Europe to the USA, in which hydatid cysts caused by the Echinococcus granulosus parasite were found in their livers, although their health problems were not related to these cysts.

Case Reports

• The first case involved a 21-year-old Thoroughbred stallion, imported from Ireland eight years before the study but initially born in France. Symptoms and clinical examinations suggested the horse had a pituitary tumor. A histopathological examination confirmed a pituitary adenoma and also revealed a hydatid cyst caused by Echinococcus granulosus in the liver. However, this cyst was determined not to be the cause of the horse’s health problems.
• The second case was a 12-year-old Thoroughbred mare and her aborted fetus found dead in a pasture. The cause of death was suspected to be lightning strike, supported by the presence of severe burn marks on the horse’s limbs and singed areas along the back. The mare had been imported from Ireland three years before the study.

Necropsy Findings

• For the first horse, necropsy revealed various abnormalities including shaggy hair, crusty dry skin, atrophy of both testicles, vegetation of the aortic valves, enlarged adrenal glands and pituitary gland with a tumor and a cyst in the liver. Microscopic changes were determined to be secondary to the pituitary tumor or normal aging phenomenon.
• For the second horse, necropsy findings related to the cause of death were not described in the given abstract.

Implications

• The main implication of this study is that Echinococcus granulosus, a parasite normally found in dogs and livestock but can infect humans, can also infect horses.
• These findings suggest the need for further studies to understand the pathogenic importance of hydatid cysts in horses and possible transmission risks to humans.