322 Cow Pox. 



Occasionally infection of such wounds may lead to the develop- 

 ment of severe ulcerations, which considerably retard the heal- 

 ing process. Frequently 30 to 40 days may be required in such 

 cases for recovery. Exceptionally a parenchymatous mastitis 

 may be associated with the eruption of pox. As the milk is 

 mixed with the secretion of the wounds it of course becomes 

 contaminated. 



In rare cases eruptions resembling those which occur on 

 the udder of cows may develop on the scrotum of male animals. 



A generalized pox eruption occurs only very rarely (Dupuis 

 observed it in two cases, Strebel in one instance). In such 

 cases the eruptions, which may reach the size of hazelnuts, 

 appear, associated with febrile symptoms, on the udder, also 

 on the inner surface of the thigh, on the croup, rump, chest, 

 neck and in the muzzle. (In Strebel 's case paralysis of the 

 stomach aiid intestines was observed in the later course of the 

 disease, and after a temporary improvement of 8 to 10 days, a 

 fatal peritonitis developed.) 



Diagnosis. The diagnosis of cow pox is based on the pres- 

 ence of roundish or oval vesicles containing a depression, in the 

 center. In some cases the spreading of the eruption to other 

 animals and a similar exanthema on the hands of the attendants 

 handling the affected animals, may reveal the nature of the 

 affection. The injuries and irritations which are usually caused 

 by the milking, may sometimes interfere with the establishment 

 of a diagnosis. 



It is possible to mistake the exanthema for that of foot- 

 and-mouth disease, but in this the vesicles do not develop from 

 nodules, they are larger and less uniform in appearance, and 

 similar vesicles are present in the mouth and in the interdigital 

 spaces of the affected animals in the stable. The benign, coital 

 vesicular-exanthema is readily recognized by the simultaneous 

 affection of the genital organs. Pustules may sometimes also 

 develop on the udder in rinderpest, but these findings are unim- 

 portant as compared with the other general and local manifes- 

 tations of the disease. 



The nature of the eruptions, which have been described by Ger- 

 man authors as "wind and stone pox," is as yet doubtful, nevertheless 

 the possibility does not appear to be excluded that they represent 

 abortive forms of true cow pox. According to description they form 

 hard nodules which develop on the lower part of the udder and on the 

 teats, and change into purulent vesicles. In doubtful cases the inocu- 

 lation of a calf would readily reveal the nature of the affection in a 

 short time. 



Ehrhardt described under the name of false cow pox (pointed pox, 

 variceUae) a stable disease of cows, in the course of which desquama- 

 tion of epithelium from the teats occurs, causing severe inflammation. 

 In one case the milker also became affected, his hand was greatly swollen, 

 and numerous vesicles up to the size of a pea appeared on his skin, 

 causing considerable pain. 



