754 Diseases of the Genital Organs 



This parasite constitutes an exception to the general rule 

 in the trypanosomic group of diseases, in that it is not 

 transmitted from animal to animal by the bite of an insect. 



Symptoms. The period of incubation following natural 

 infection is not definitely determined and varies considerably 

 in different cases. Generally there appear some physical 

 signs of disease in from eight to ten days after exposure, 

 but these may not be very marked and may pass unnoticed 

 by an inexperienced observer. 



The symptoms of the disease may be divided into three 

 important groups : the local lesions of the genital organs and 

 the contiguous parts ; those of the skin and other mucous 

 membranes than that of the genital organs; and the symp- 

 toms which emanate from the central nervous system. The 

 local symptoms in the genital organs are the first to appear 

 after infection and usually the last to disappear in case of 

 recovery. 



In the stallion there usually appears, eight to ten days sub- 

 sequent to infection, a swelling of the penis and prepuce, 

 with some degree of protrusion of the penis, still covered by 

 the prepuce. The prepuce shows a tense, elastic swelling 

 and has a smooth, glistening appearance. If the urethra is 

 exposed to view, its meatus will be found swollen, dark red, 

 and intensely injected. From it exudes a small amount of a 

 thin, dirty, muco-purulent discharge. As the disease pro- 

 gresses, the tumefaction of the prepuce and penis increases 

 and extends to the sheath and scrotum, which may eventually 

 become enormously swollen and remain in an indurated con- 

 dition for one to two years or more. The animal gradually 

 becomes less able to retain the penis in its position, and the 

 swollen organ protrudes farther and farther out of the 

 sheath, sometimes extending entirely out of the prepuce and 

 hanging flaccid and fully exposed. The discharge from the 

 urethra may become somewhat ichorous and, with the gen- 

 eral soiled condition of the penis and surrounding parts, 

 may lead to ulcerations and erosions upon these. Later in 

 the course of the disease, the weakened condition of the 

 tissues of the pari may lead to purulent infection and the 



