Exanthema of the Udder 969 



lesions upon the teat and udder cause a purulent infection, which 

 furnishes a supply of highly virulent pus, ready to induce infec- 

 tion at any time that it may chance to find entrance through the 

 teat canal into the milk cistern and thence into the milk canals. 



The source and character of the infection of the cow pox is 

 unknown. In some cases, however, it is traceable to vaccination 

 in man. The milker may have been vaccinated, or may have 

 handled the vaccination wounds in children or others who have 

 been vaccinated, and thus may bear the disease, upon his hands, 

 to the teats of the cows while milking. Once the affection has 

 gained entrance into a dairy stable, it is readily transmitted by 

 the hands of the inilkers from one cow to another. 



The handling of cow pox in dairy cows is chiefly prophylactic, 

 and consists of the application of the fundamental rules of disin- 

 fection. So far as is practicable, the affected cows should be 

 isolated from the sound ones, and should be milked last. If the 

 disease exists in a dairy stable, the hands of the milkers should 

 be thoroughly disinfected before and after the milking of each cow. 

 In our j udgment the best disinfectant for this purpose is corrosive 

 sublimate, because of its efficiency and absence of odor. 



Ift Jfl -fi 'I^ ■T» 'I* 



We meet from time to time, in various localities, with other 

 forms of exanthema of the teats and udder. 



In the vicinity of Ithaca, N. Y., there has prevailed from time 

 to time a disease having the general clinical characters of an in- 

 fection. So far as we have been able to observe, the disease is 

 unaccompanied by the formation of vesicles, pustules or other 

 lesions to definitely identify it with cow-pox. At first there 

 appear small inflamed areas in the skin of the teat or contiguous 

 parts of the udder. Later the areas become hemorrhagic, and 

 finally necrotic, when they dessicate, turn black and constitute 

 a large scab, which is exceedingly hard, tough and adherent. 

 The number of these necrotic areas is usually Hmited to from 

 two to five or six upon the entire udder and teats. They vary 

 in size from oLe-quarter to one-half inch, or even more, in diame- 

 ter. Ordinarily the disease pursues a comparatively benign 

 course ; but the diseased areas are sensitive and painful, so that 

 the cow resists being milked. In some cases the disease is fol- 

 lowed by a very destructive streptococcic mammitis, which usu- 

 ally leads to the permanent destruction of the affected quarter 



