Terminal sterility in a Friesian bull naturally infected with chronic scrotal cutaneous streptothricosis (Kirchi ).

Some seminal characteristics of a Friesian bull were routinely studied during a period of 25 months. At the 8th month, the bull had natural infection of cutaneous streptothricosis. Lesions were scattered on the body, legs, and scrotum (Figures 1,2,3). Lesions became conspicuous on the scrotum at the 18th month; until this period, the seminal characteristics were normal and unaffected by the disease (Table 1). Monthly treatments with long-acting terramycin injectable solution commenced as soon as lesions were noticed until the animal died. No improvement was noticed; lesions became pronounced particularly on the bull's scrotum (Figures 2,3). Semen collection was suspended for about five months while the bull was transferred to the veterinary clinic for continued treatment. Six months after lesions became conspicuous on the entire scrotal wall (Figures 2,3), several ejaculates were collected weekly within six weeks at the rate of two or three samples per trial. The ejaculates were watery, clear, transparent and contained no spermatozoa because spermatogenesis had stopped and the bull had become sterile.