Ten thousand bedraggled horses last week limped in herds through the San Carlos Indian reservation, an arid section of Arizona. They searched for water but found death. No one owned them, or wanted to own them. They were scrawny, bigheaded beasts, physically degenerate. Practically every one of the 10,000 was infected with dourine.
Dourine is a genital disease peculiar only to horses. It swells their groins and eventually paralyzes their hind quarters. The cause of the disease is a trypanosome, brother of the trypanosome which causes human sleeping sickness and distant relative of...