INFECTIOUS DISEASES OF CATTLE. 455 



extreme weakness and emaciation, constant lying down, with stiffness 

 and marked difficulty in standing. 



The disease frequently extends to the nasal cavities, producing a 

 thin, yellowish or greenish yellow, sticky discharge which adheres 

 closely to the borders of the nostrils. Their edges also show caseous 

 patches similar to those in the mouth. Sometimes the nasal passage 

 is obstructed by great masse3 of the necrosed exudate, thus causing 

 extreme difficulty in breathing. "When the caseous process involves 

 the larynx and trachea there result cough, wheezing, and dyspnea, 

 together with a yellowish mucopurulent expectoration. 



When life is prolonged three or four weeks, caseous foci may be 

 established in the lung, giving rise to all the signs of a brcncho-pneu- 

 monia. Many of these cases are associated with a fibrinous pleurisy. 

 The invasion of the gastrointestinal tract is announced by diarrheal 

 symptoms. This disease principally attacks sucklings not over 6 

 weeks of age, but calves 8 and 10 months old are frequently affected, 

 and several cases in adult cattle have been reported to this office. 



In its very acute form many of the cases run their course in from 

 five to eight days. In these the local lesions are not strongly marked, 

 and death seems due to an acute intoxication. In other enzootics 

 the majority of the affected animals live from three to five weeks. 

 These are the cases that occasionally present the pulmonary and intes- 

 tinal symptoms, and sometimes develop also caseonecrotic lesions in 

 the liver. 



Ordinarily eases show no tendency to spontaneous cure. Left to 

 themselves they die. On the contrary, if taken in hand early the dis- 

 ease i3 readily amenable to treatment. In the latter event the pros- 

 pects of recovery are excellent. 



Differential diagnosis. — Necrotic stomatitis may be differentiated 

 from foot-and-mouth disease by the fact that in the latter disease 

 there is a rapid infection of the entire herd, including the adult cattle, 

 as well as the infection of hogs and sheep. The characteristic lesion 

 of foot-and-mouth disease is the appearance of vesicles containing a 

 sercus fluid upon the mucous membrane of the mouth and upon the 

 udder, teats, and feet of the affected animals. In necrotic stomatitis 

 vesicles are never formed, necrosis occurring from the beginning and 

 followed by the formation of yellowish cheesy patches principally 

 found in the mouth. Mycotic stomatitis occurs in only a few animals 

 of the herd, chiefly the adult cattle, and the lesions produced consist 

 of an inflammation of the mouth and lips and of the thin skin between 

 the toes, followed in a few days by small irregular ulcers in the mouth. 

 This disease appears sporadically, usually in the early fall after a dry 

 summer, does not run a regular course, and can not be inoculated. 



Prevention. — Prophylaxis should be carried out along three lines: 



(1) Separation of the sick from the healthy animals. 



(2) Close scrutiny and thorough disinfection once or twice daily for 



