334 PARASITES OF THE DOMESTIC ANIMALS 



ine has appeared at various times within certain Hmits in the United 

 States. 



Infection. — Dourine is a pecuhar trypanosomiasis in that there is 

 no intermediate carrier of the trypanosome specifically responsible for 

 it. Like the spirochete of human syphilis, it is inoculable by contact, the 

 infection usually occurring during the act of copulation, though reported 

 cases of the disease in geldings and in mares which have never had the 

 stallion would indicate that its transmission is not entirely by copulation. 

 It may be artificially transmitted to horses and to other susceptible 

 animals, as dogs and rabbits, by inoculation with blood from animals 

 affected. Sexual intercourse is, however, by far the most common means 

 of natural infection, the trypanosome reaching the blood by penetrat- 

 ing the intact mucosa of the genital tract. 



Symptoms. — The symptoms of dourine as given by John R. Mohler 

 (Bureau of Animal Industry, Bulletin No. 142, 1911) are, with some 

 omissions, here quoted. 



"There are many variations in the symptoms of dourine, and this is 

 particularly true of the disease as it occurs in this country. Two dis- 

 tinct stages may be noted which vary somewhat from those described 

 in textbooks, but probably no more than could be expected when 

 differences of climatic conditions and methods of handling are taken 

 into consideration. 



"The first stage chiefly concerns the sexual organs, and therefore 

 differs somewhat in the male and female. In the second stage symptoms 

 indicating an affection of the nervous system are more prominent and 

 are not dependent on the sex of the animal. 



"Following a variable period of incubation of from eight days to two 

 months, there is seen in the stallion an irritation and swelling about 

 the penis first noticed in the glans. This swelling extends throughout 

 the organ, and the penis may be continually protruded and frequent 

 ei-ections noticed. The edematous swelling also involves the groin, 

 with enlargement of the adjacent inguinal glands, and extends forward 

 along the abdomen. In a few days small vesicles or blisters appear on 

 the penis, which break, discharging a yellowish serous fluid and leaving 

 irregular raw ulcers. Where primary ulcers are in proximity to each 

 other there is a marked disposition to coalesce, a large raw surface with 

 irregular border resulting. The ulcerative process may form a wound 

 extending almost entirely around the penis. The ulcers show a tendency 

 to heal rapidly, leaving white cicatrices which are permanent. In some 

 cases the urinary meatus is very red and swollen, and according to some 

 observers, especially European, more or less thick catarrhal exudate 

 is discharged from its oriface. This condition, however, has been rarely 

 seen in cases in this country, a more or less continuous dripping from 

 the urethra of a yellowish serous-like discharge alone being present. 



