Dourine  

Dourine is a contagious chronic parasitic disease that affects equine species. The incubation period ranges from several weeks to several years. Clinical symptoms vary depending on the virulence of the strain, the nutritional status of the horse, and stress factors. The most prominent symptoms include swelling of the genital organs, facial paralysis, and incoordination.  

Facts About the Disease:  

Transmission occurs directly from one animal to another during mating.  

No natural reservoir of the parasite is known other than infected horses.  

The causative agent, Trypanosoma, differs from other trypanosomes in that it is rarely detected in the blood.