FOOT AND MOUTH DISEASE 439 
epithelium of the mucous membrane caused by a serous exudation. 
There is no deeply rooted inflammation of the mucous membrane or 
corium; the sore simply consists in the laying bare of the surface of 
these parts and it has a natural tendency to heal quickly. 
The tissue changes reported on 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. In 
cases which lead to sudden death, the most pronounced change is 
usually found in the heart muscle. This condition has been carefully 
studied in cattle by Jost and Zschokke and in pigs by Hebiger. They 
find an extensive myocarditis which can be noted by the yellowish 
streaks which are shown on the heart. In pigs Heebiger describes an 
Fic. 102. MICRO-PHOTOGRAPH OF HEART MUSCLE SHOWING DEGENERATION AND 
LEUCOCYTIC INFILTRATION (Zschokke). 
“albuminoid” degeneration of the myocardium. These changes in 
the heart seem to be characteristic of this type of the disease. There 
may be associated with the primary heart lesions congestion and 
cedema of the lungs. The mucous membrane of the stomachs and 
intestines may be dark red and numerous hemorrhages are sometimes 
found. Ulcers or erosions up to an inch in diameter may be present 
on the mucous membrane of the pharynx, rumen and abomasum. 
Ulcers of a nature similar to those found in the stomach occur in the 
intestines. 
On the feet inflammations may follow the simple vesicles about the 
coronet. These may extend deep into the tissues, pass under the hoof 
and cause it to slough off, extend into the bone producing necrosis or 
