MORBID ANATOMY 



457 



ed with reddened areas deprived of the superficial layer of the 

 skin and are very tender. The healing, however, goes on 

 quite rapidly. The milk is said to be somewhat changed in 

 appearance and unfit for making butter or cheese. These are 

 the main symptoms accompanying the uncomplicated cases of 

 foot and mouth disease. In all such cases recovery is usually 

 rapid and complete. In certain other cases, however, compli- 

 cations arise which are not only injurious but may be fatal. 

 Thus the mouth lesions may be accompanied by nasal catarrh 

 or pneumonia. The feet may become very much swollen and 

 the inflammation and suppuration extend to the tendons and 

 bones, resulting in the loss of the hoof. Such cases are usual- 

 ly fatal. As a result of the general affection young calves may 

 succumb to a secondary inflammation of the stomach and 

 bowels and older animals may abort or suffer from inflamma- 

 tion of the udder. 



The duration of the disease \-Q uncomplicated cases varies 

 from lo to 20 days. When complications occur either with 

 the regular course or as sequelae the duration becomes indefi- 

 nite. The mortality varies with the severity of the attacks, 

 the age and condition of the animals and the treatment. 

 Ordinarily the mortality is not high, excepting in very young 

 animals. 



S 363. Morbid anatomy. The tissue changes found at 

 post-mortem vary to a marked degree. There are in certain 

 cases hyperemia and edema, catarrh of the nares and mucosa 

 of the lungs and dilatation of the heart. There may be fatty 

 degeneration and hemorrhagic infarcts in the heart muscle. 

 In other cases there is severe gastro- enteritis with intestinal 

 hemorrhage. In the stomachs of cattle oval reddish areas 

 which ultimately form ulcers appear. These often become 

 confluent. The involved portion of the mucous membrane 

 becomes thickened. The areas of necrotic tissue in which the 

 ulcers appear become surrounded by a reddish line of demar- 

 cation which, in the healing process, forms a cicatrix. The 

 lesions on the mucous membrane rarely extend deeper than 



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