INFECTIOUS DISEASES ol9 



Microscopic examination of a section of one of tlu-se areas reveals a 

 central mass of tissue debris composed of disintegrating and de- 

 stroyed cells which do not stain. SuiTounding the necrotic area is 

 a zone made up of leukocytes, damaged tissue cells, and considerable 

 nr.mb'ers of Bacillus necrophorus filaments arranged in bundles. The 

 surrounding tissue evidences a severe reaction by hyperemia, and the 

 presence of large numbers of leukocytes and a few Bacilli necro- 

 phorus. 



Necrobacillosis assumes many different forms, the most common of 

 which are necrotic stomatitis, enteritis, rhinitis, pneumonia, hepatitis, 

 splenitis, vaginitis, and dermatitis. 



NECROTIC STOMATITIS 



Necrotic stomatitis is probably the most common form of necro- 

 bacillosis. It is of frequent occurrence in suckling pigs. 



Lesions and symptoms. — The inflaimmation usually begins at the 

 margins of the gums. The successive changes in the affected areas 

 are as follows : The surface is red or bluish red, becomes tumefied, 

 is very sensitive, and bleeds easily. Two or three days later the 

 area becomes yellowish white or even brown in color and of a mushy 

 consistency, and usually sloughs, leaving an eroded surface which 

 is covered by a coagulated necrotic tissue and appears as a diph- 

 theritic membrane. The surrounding tissue becomes red, tumefied, 

 and sensitive. The disease process gradually extends and ultimately 

 becomes confluent, forming large eroded areas. A similar process 

 frequently affects the lips simultaneously. 



The affected pigs frequentlj' attempt to nurse, but the gums are so 

 sensitive that they obtain little nourishment. Pigs may transmit 

 the disease to the teats of their mother by nursing. There is saliva- 

 tion and champing of the teeth. Upon inspection the foregoing 

 lesions are observed and a peculiar disagreeable odor is also noted 

 which may permeate the air and be recognized at a considerable dis- 

 tance. As tlie disease progresses the discharged saliva becomes bloody 

 and contains shreds of tissue. 



The course of this disease varies from a few days in the acute form 

 to several weeks in the chronic form. 



Diagnosis. — The identification of necrotic stomatitis is not difficult 

 if the typical necrotic lesions are observed and the peculiar offensive 

 odor is recognized. 



Treatment. — In the early stages the treatment of the cases may be 



