400 DISEASES OF CATTLE. 



Diagnosis. — The recognition of this affection should not, as a rule, 

 be difficult, especially when the disease is known to be in the vicinity ; 

 in fact, the group of symptoms forms a clinical picture too decided 

 to be doubted. The combination of high fever, vesicular inflamma- 

 tion of the mouth, and hot, painful, swollen condition of the feet, 

 followed in 24 to 48 hours by the appearance of numerous small 

 vesicles varying in size from that of a pea to that of a hazelnut on 

 the udder and feet and in the mouth should prevent any serious or 

 long-continued error in the diagnosis. However, in the inoculation 

 of calves we have a certain and final test. In 24 to 72 hours after 

 inoculation the calves present the characteristic vesicles. Such in- 

 oculation should be practiced, however, only by officials who are 

 properly authorized to deal with contagious diseases. 



Differential dia/jnosis. — It can be asserted positively that no dis- 

 ease of cattle closely simulates the symptoms of the eruption of aph- 

 thous fever on the lining membrane of the mouth. Cowpox or horse- 

 pox may be accidentally transmitted by inoculation. But the erup- 

 tion in the " pox " goes on to the development of a pustule, Avhile in 

 foot-and-mouth disease the eruption is never more than a vesicle, 

 even though the contained fluid may become turbid. 



The inoculation test in the case of cowpox does not respond with 

 fever and erujjtion for at least 10 days, and often longer. 



In mycotic stomatitis or inflammation of the lining membrane of 

 the mouth the entire buccal cavity is inflamed, and in a few days the 

 croupous membrane forms, peels off, and exposes a raw, bleeding 

 surface, while the thin skin between the toes may also be inflamed. 

 The 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, charac- 

 teristically, the hoof, together with the absence of infection in the 

 herd and the complete negative character of inoculation of calves, 

 distinguish 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 

 extending entirely around- the limb and forming a distinct line of 

 demarcation 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 



