248 THEORY AND PRACTICE 



and in the mare. The eruption is a simple blister called a 

 phlyctena. This occurs in the male sometimes on the body of 

 the penis. The period of inoculation is from 24 hours to 3 days. 

 The lips of the vulva swell as large as the wrist. In the stallion 

 the sheath swells. The disease is transmissible from one animal 

 to another by coition. No special constitutional disturbance is 

 produced. The disease is self-limiting and if copulation ceases 

 recovery will take place in 5 to 10 days. 



Treatment. — Give cool laxatives and mild stimulants. For a 

 local application use sulphate of zinc (5 grains) to the ounce of 

 water. Bathe the parts three times a day. This disease is also 

 known as coital exanthema. 



MALIGNANT POX. 



Malignant pox is known as dourine or equine syphilis. The 

 disease was brought to this country from France. In 1817 it was 

 known in Prussia; in 1821 in Hungary; in 1836 in Italy. It has 

 never been known in Belgium or England. The special pathology 

 of this disease was gotten from Tanhoffer. 



Etiology. — The trypanosoma equiperdum is the specific para- 

 site causing the disease. It is a single-celled animal parasite. 

 This parasite was discovered in South Africa in connection with 

 the tsetse fly disease and sleeping sickness. The lesions resemble 

 syphilis in the human, but the two are different. Syphilis is 

 transmissible from parent to off-spring in the human but dourine 

 is not in the horse. A syphilitic stallion cannot impregnate a 

 mare. If a syphiHtic mare should conceive she will abort or 

 else the foal will be born dead. 



Semeiology. — The elevated plaques on the body and pustules 

 on the penis and vulva are the first noticeable indications of the 

 disease. These ulcerate. They may occur on the glans penis 

 and are accompanied by the swelling of the sheath. In the mare 

 the vulva swells, and turns out, exposing the clitoris to view. 

 The appetite is poor and the animal becomes lazy. If the disease 

 occurs in an acute form, it will kill ; if it is chronic, in the course 

 of a month or so the animal begins to be wabbly in his hind parts. 

 Sometimes the ulcers heal and are replaced by others. After a 



