260 DISEASES OF CATTLE. 



uncommon in the horse, attacking the heels, the lips, or some other 

 inoculated part of the body, and is then easily transferred to the cow, 

 if the same man grooms and dresses the horse and milks the cow. It 

 may also appear in the cow by infection, more or less direct, from a per- 

 son who has been successfully vaccinated. Many believe that it is only 

 a form of the smallpox of man modified by passing through the system 

 of cow or horse. It is, however, unreasonable to suppose that this 

 alleged modified smallpox could have been transmitted from child to 

 child (the most susceptible of the human race) for ninety years, under 

 all possible conditions, without once reverting to its original type of 

 smallpox. Chauveau's experiments on both cattle and horses with the 

 virus of smallpox, and its inoculation back on the human subject, go 

 far to show that in the climate of western Europe, at least, no such 

 transformation takes place. Smallpox remains smallpox and cowpox 

 cowpox. Again, smallpox is communicable to a person who visits the 

 patient in his room but avoids touching him, while cowpox is never 

 thus transferred through the air unless deliberately diifused in the form 

 of spray. 



The disease in the cow is ushered in by a slight fever, which, how- 

 ever, is usually overlooked, and the first sign is tenderness of the teats. 

 Examined, these may be redder and hotter than normal, and at the end 

 of two days there appear little nodules, like small peas, of a pale red 

 color, and increasing so that they may measure three-fourths of an inch 

 to 1 inch in diameter by the seventh day. The yield of milk diminishes, 

 and when heated it coagulates slightly. From the seventh to the tenth 

 day the eruption forms into a blister with a depression in the center 

 and raised margins, and from which the whole of the liquid can not be 

 drawn out by a single puncture. The blister, in other words, is cham- 

 bered, and each chamber must be opened to evacuate the whole of the 

 contents. If the pock forms on a surface where there is thick hair it 

 does not rise as a blister, but oozes out a straw-colored fluid which con- 

 cretes on the hairs in an amber-colored mass. In one or two days after 

 the pock is full it becomes yellow from contained pus, and then dries 

 into a brownish yellow scab, which finally falls, leaving one or more 

 distinct pits in the skin. Upon the teats, however, this regular coiirse 

 is rarely seen; the vesicles are burst by the hands of the milker as soon 

 as liquid is formed, and as they continue to suffer at each milking they 

 form raw, angry sores, scabbing more or less with intervals, but slow 

 to undergo healing. 



The only treatment required is to heal the sores, and as milking is 

 the main cause of their persistence that must be done as gently as 

 possible, or even with the teat tube or dilator (Plate xxiv, Figs. 3 and 4). 

 It is essential to check the propagation of the germ, and for this pur- 

 pose the sore teats may be washed frequently with a solution of half 

 an ounce hyposulphite of soda in a pint of water. This will usually 

 check the inflammation and cut short the malady. 



