FOOT-AND-MOUTH DISEASE 381 



Diagnosis.— In typical cases, during the vesicular stage 

 of the eruption, the diagnosis-is not difBcult. The presence of 

 vesicles, the foot lesions, the rapid spread of the contagion 

 and the ease with which it may be transmitted artificially 

 characterize the disorder. 



Diiring the early stages (before the eruption) and at the 

 end of a sporadic outbreak (vesicles healed or only secondary 

 changes present) the diagnosis can be extremely difiicult. 



Foot-and-mouth disease may be confused with various 

 forms of stomatitis in cattle, none of which are contagious 

 but some of which are attended with vesicle formation. The 

 most important are the following: 



(a) Traumatic Stomatitis ("tooth cuts") presents lesions on 

 the bars, lips and dental pad. There is no vesicle formation 

 and the wounds have sharp borders and are deep. 



(6) Mycotic Stomatitis of Cattle, a non-contagious foot and 

 mouth affection widespread in the United States. Vesicles 

 rarely appear and are never well developed. The mouth 

 lesions are more ulcerous in character than in foot-and-mouth 

 disease and are more apt to involve the deeper structures. 

 There is more swelling of the limbs but no vesicles occur at the 

 coronets. A peculiar reddish-brown coloration of the muzzle, 

 udder and teats is considered characteristic by some authori- 

 ties. The disease cannot be transmitted by inoculation and 

 does not affect sheep or swine. Often only a few animals in 

 a herd are attacked. 



(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 laut a necrosis of the mucous membrane, 

 yellow-gray patches developing in the mouth (cheeks, 

 tongue). 



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

 digital space which may later induce suppurative pododerma- 



Digitized by Microsoft® 



