350 ACUTE EXANTHEMATOUS INFECTIOUS DISEASES 



(c) Ergotism. — Ergotism produces gangrene of the distal 

 portions of the extremities (feet, ears, tail), the necrotic parts 

 sloughing. Blisters are not common and when present not 

 well marked. This poisoning is not contagious and cannot be 

 transmitted artificially from animal to animal. It occurs 

 only among cattle which have eaten ergot-of-rye. 



(d) Necrotic Stomatitis.— -Nearly always seen in calves 

 ("calf diphtheria") and pigs ("sore mouth"). There is no 

 vesicle formation but a necrosis of the mucous membrane, 

 yellow-gray patches developing in the mouth (cheeks, 

 tongue). 



(e) Foot-rot of Sheep. — A contagious disease of the inter- 

 digital space which may later induce suppurative pododerma- 

 titis, tendovaginitis, open joint, etc. There are no vesicles 

 and the disease spreads slowly through a flock. 



(/) Foul-in-the-feet of cattle due to filthy stables and barn- 

 yards does not affect the mouth; there are no vesicles and no 

 contagion. A malignant type of foul-in-the-feet due to the 

 necrosis bacillus and appearing in cows soon after parturition 

 or in advanced pregnancy, assumes the form of a necrosis of the 

 interdigital space which may involve the deeper structures 

 (matrix, tendon sheaths, tendons, joints) . It is attended by 

 fever when secondary infection is present. The mouth is not 

 involved. 



The indications which point to foot-and-mouth disease in 

 a recently recovered animal are: Pytalism (usually profuse); 

 yellow cicatrices or areas on gums and dental pad; small red 

 spots and erosions in the gums and borders of the muzzle. 

 These traces are said to persist for several weeks. 



Course. — In most outbreaks the course is benign. Indivi- 

 dual vesicles usually heal in five or six days, but as they do not 

 all erupt at the same time, the duration is often extended two 

 or three weeks. The mouth lesions heal more rapidly than 

 do those of the feet. As all animals are not infected simul- 

 taneously, an outbreak will last in a given barn one or two 

 months. 



In calves (under two months) the course is more rapid and 

 fatal (toxemia, septicemia, pyemia, gangrenous pneumonia, 

 heart muscle degeneration) leading to death in three or four 

 days. 



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