INFECTIOUS DISEASES OF CATTLE. 385 



previous history of the case; the failure of the vesicles, if any appear, 

 to spread extensively; the absence of vesicular eruptions on other 

 portions of the body, notably the udder and teats, and, characteris- 

 tically, the hoof, together with the absence of infection in the herd 

 and the complete negative character of inoculation of calves, distin- 

 guish between the local disease named and foot-and-mouth disease. 



The lesion resulting from ergotism may be differentiated from those 

 of foot-and-mouth disease by the lack of eruptions in the mouth and 

 by the location of the disease at the tips of the ears, end of the tail, 

 or upon the lower part of the legs, usually below the knees or hocks. 

 The lesion of ergotism does not take the form of pustules or blisters, 

 but manifests itself first as a swelling about the ankle, which later 

 may slough and circumscribe the limb, forming a deep crack extend- 

 ing entirely around the limb and forming a distinct line of demarca- 

 tion between the healthy skin above and the diseased below. The 

 absence of ulcerous sores on the coronet and between the claws, 

 together with a healthy condition of the membranes of the mouth 

 and the knowledge that the lesion upon the limb in question extends 

 uninterruptedly around it, should point conclusively to a diagnosis 

 of ergotism and to the exclusion of all fears of foot-and-mouth disease. 



In foul foot or ground itch of cattle the inflammation of the skin 

 and toes is general and not in certain spots as in foot-and-mouth dis- 

 ease ; the mouth remains unaffected, and the presence of the disease 

 may be traced to filth and poor drainage. 



The severer forms of the disease might be confounded with certain 

 general diseases. Where gastro-intestinal symptoms predominate 

 acute gastric catarrh or inflammation of the intestines might be 

 thought of. Involvement of the lungs might lead to a diagnose of 

 acute congestion of the lungs or pneumonia. The distinction is 

 apparent in these diseases by the lack of vesicular eruption on the 

 mucous membrane or skin, and also by lack of evidences of infection 

 in the herd or neighboring animals. 



Prophylaxis. — The measures to be adopted to prevent the spread of 

 the affection must take into consideration the highly infectious nature 

 of the disease, its ease of dissemination, and the liability of the virus 

 to live a saprophytic life for long periods. Great care should there- 

 fore be observed in keeping healthy animals unexposed to the con- 

 tagion. When an outbreak occurs in a community the owner should 

 make every effort to keep other animals from coming in contact with 

 his diseased cattle. This especially applies to dogs, cats, goats, and 

 poultry, which usually have access to the stables and barnyards and 

 in this way furnish excellent means for disseminating the infectious 

 principle. He should be equally particular in prohibiting any person 

 from coming onto his premises, especially an attendant or owner or 

 other person in any way connected with cattle. Such a herd may 

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