214 COMMON AILMENTS OF CATTLE 



very slowly from animal to animal, but will spread readily by 

 the hands of the milker. Cow-pox is very closely associated 

 with human small-pox. 



Cases of cow-pox have been reported to occur in cows that 

 had been milked by persons affected with small-pox. Young, 

 healthy calves are used for the production of small-pox vaccine. 



Cause. — The cause of cow-pox has not yet been determined. 

 It is thought to be due, however, to germs (bacteria) which are 

 ultra-microscopic, too small to be seen by aid of the microscope. 



Symptoms. — Cow-pox is usually accompanied by a slight 

 elevation of temperature. This condition is not, however, 

 always constant. The age of the cow is an important factor in 

 making a diagnosis, as the disease affects chiefly young cows. 

 The milk flow may or may not be decreased. The eruptions of 

 the vesicles (blisters) occur on the teats and the adjoining- 

 parts of the udder. The development of the pocks are divided 

 into well-marked characteristic stages. The first stage of the 

 eruption consists of pink-colored pimples about the size of a 

 pea. The pimple subsequently changes into a blister which 

 contains a sticky, whitish fluid. The blisters on the teats vary 

 in form, while the ones on the udder are circular and show a 

 depression in the center. The blisters vary in size, some meas- 

 uring as much as one-half to one inch in diameter. When the 

 pocks occur on the surface covered with long hair, they do not 

 form blisters, but discharge a straw-colored fluid which cements 

 the hair and forms a brownish-yellow mass. The blisters ma- 

 ture about the tenth day and then dry up into a dark brown 

 crust which drops off a few days later, leaving a scar. Many of 

 the pocks are ruptured during milking, causing the frequent 

 formation of angry-looking sores which heal slowly. Only in 

 rarer cases does the disease affect other parts of the body. 



Treatment. — Local treatment is all that is required. A 

 separate attendant should be provided to care for the diseased 

 animals. They should be milked carefully so that the blisters 

 will not become ruptured. The persistent sores may be washed 

 with mild antiseptic solutions. The attendant should keep his 

 hands and arms washed with an antiseptic Application of zinc 

 oxide ointment to the ruptured pocks will be beneficial. 



