DISEASES OP CATTLE. 13-: 



color of the udder. True cow pox always shows these phe 

 nomena, but awkward milking, incorrect treatment and manj 

 other circumstances often conspire to change its appearanci 

 and defer the cure. The number of the spots, as well a; 

 their size, varies. In some cases only a few, and in other; 

 thirty, forty or even more appear. Sometimes they becomi 

 no larger than a pea, while at others they reach the size 'oJ 

 a dime. Frequently eruptions of different sizes are founc 

 on the same animal, but they rarely appear simultaneously 

 Their appearance is generally gradual, and the last ma; 

 not be developed until one or two weeks after the first 

 For this reason the udder may be covered with eruptions ii 

 all the different stages of their development. In man; 

 cases, especially if many and large tumors are present, th 

 udder is more or less sensitive and swollen, which may b 

 caused by the fact that the cow cannot be milked at all, o 

 only partially. No other symptoms of disease except th 

 local ones are perceived, and the animal appears to be pei 

 fectly healthy. Rarely a fever makes its appearance, an( 

 then the cow eats little or not at all, does not chew the cue 

 and yields less and thinner milk than usual. These symj 

 toms are present only from a few days before the eruptio: 

 appears to its complete development, and they always dis 

 appear when the tumors dry up. The cow pox is most frc 

 quent in the middle period of life and in the first few month 

 after calving ; but it has been observed on cows two year 

 old, which had never calved, and in old cows that ceased t 

 give milk. The disease appears in all countries, and tope 

 graphical position or climate seems to exercise no perceptibl 

 influence. Thedisease is of more frequent occurrence in sum 

 mer than in winter. Everything tending to produce a rus' 

 of blood to the udder, the change from poor and scanty t 

 copious and nutritious food, and the more plentiful secre 

 tion of milk after calving, facilitate its development. 



12 



