Ear mange in horses.

This study investigates a condition in horses characterized by severe ear itching, identified as being caused by small, white mites called Psoroptes. The condition is more common in yearlings, particularly those bred on stud farms, and treatment with gamma benzene hexachloride was found to be effective in eradicating the parasites.

Research Benchmarks

• Investigation of a pathological horse condition manifesting as extreme ear itching
• Macroscopic identification of small white mites in the horse’s ear
• Microscopic confirmation that the mites are of the species Psoroptes

Key Observations

• The horse displays intense irritation, holds its ears at unusual angles, frequently attempts to scratch its ears and rub the base of the ear on firm objects, and it commonly lowers its head below the normal level.
• The issue is notably more prevalent in yearlings, specifically those reared on stud farms. This suggests that the condition may be transmitted by mares on these farms, however, the mares do not appear to suffer the same levels of discomfort.
• The types of horses observed to be affected by this condition include Thoroughbreds, Standardbreds, and Hunters.

Treatment and Follow-up

• All the studied horses were treated with gamma benzene hexachloride. The treatment procedure involved administering drops of this preparation into each ear daily for a week.
• After treatment, examination of most horses did not reveal remaining parasites. However, some horses continued to display irritation for some duration.
• Possible reasons for persistent irritation include the residual waxy ear secretion or the emergence of mites from eggs that the medication did not affect. As such, periodic treatment may be required to completely eradicate the parasites from the horses’ ears.