VARIOLA 135 



VARIOLA (Cow Pox) 



This disease, in cattle, runs a mild course in nearly 

 every instance and, in this country, may be looked 

 upon as being confined almost wholly to the udder. 

 Now and then a case occurs in which the animal shows 

 slight systemic derangement. 



The disease affects sometimes only a few animals in 

 a herd; at other times none escape the infection. This 

 feature is probably influenced to a great extent by the 

 sanitary or insanitary methods of milking in vogue on 

 different farms. 



The first symptom is soreness, or tenderness, evinced 

 when the cow is milked. The teat or teats feel hot 

 and slightly swollen. Soon after this, nodules develop 

 on the teats and on the udder of about the size of peas, 

 usually. In a day or two these become vesicles of a 

 bluish or purplish color. The vesicles break down, 

 leaving under them the characteristic pox ''pit," show- 

 ing granulations. The tissues immediately around the 

 pit are injected and tender. Soon the pit becomes 

 covered with a scab, which drops off in four or five 

 days, and the disease has run its course. 



If the milking is not done in a cleanly and gentle 

 manner while the pit is yet uncovered, extensive ulcers 

 sometimes form. 



The vesicles do not all appear at the same time and 

 several Aveeks may elapse before any one cow is en- 

 tirely free from lesions. The infection frequently is 

 contracted by the persons doing the milking. Pim- 

 ples, which break down and end in scab formation, 

 appear on the hands and wrists. They heal kindly and 

 usually cause no other trouble. 



