384 DISEASES OF CATTLE. 



serious illness in human consumers. The milk obtained from cows 

 suffering with foot-and-mouth disease is not readily converted into 

 either butter or cheese, but remains thick, slimy, and inert in spite of 

 churning and attempts at curdling. The ulceration of the interdigital 

 tissue may extend to the ligaments of the fetlock or produce disease 

 of the joint or bone. Pregnant animals may abort. In pigs, sheep, 

 and goats the lesions in the foot are most common, but both forms 

 may be observed or only the mouth lesions. 



When the disease has become fully established it will be found that 

 the duration of the attack will vary greatly with different animals. 

 From ten to twenty days are usually required for the recovery of the 

 normal appetite and spirits in mild outbreaks, while the return to a 

 full flow of milk, in the case of milch cows, is. seldom witnessed before 

 the arrival of the following season. 



In the malignant type of the disease it requires from three months 

 to a year for an animal to recover. The mortality is not great, gen- 

 erally about 1 to 3 per cent, but in severe outbreaks it may reach 5 

 per cent. It is more fatal in young animals that have been fed on 

 infected milk, and produces death in from 60 to 80 per cent of these 

 cases as a result of gastro-enteritis. 



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

 be difficult, especially when the disease is known to be in the vicin- 

 ity ; in fact, the group of symptoms form 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 twenty-four to forty-eight hours by the appearance of 

 numerous small vesicles varying in size from that of a pea to that of 

 a hazel nut on the udder and feet and in the mouth should prevent any 

 serious or long-continued error in the diagnosis. However, in the inoc- 

 ulation of calves we have a certain and final test. In twenty-four to 

 seventy-two hours after inoculation the calves present the character- 

 istic vesicles. Such inoculation should be practiced, however, only by 

 officials who are properly authorized to deal with contagious diseases. 



Differential diagnosis. — 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 eruption 

 in the "pox" goes on to the development of a pustule, while 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 eruption for at least ten 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 inembrane forms, peels off, and exposes a raw, bleeding sur- 

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



