116 DISEASES OF THE SALIVARY GLANDS 



cations will often produce it. Lead when given in large doses 

 will sometimes cause acute parotitis which may result in a 

 chronic induration of the gland. Inflammations of the 

 mucous membrane of the mouth from chemicals will reflexly 

 and by absorption produce an inflammation of the glands. 

 Obstruction of the ducts from chemical action or from other 

 causes of stomatitis often leads to a chronic parotitis. From 

 the retention of the secretions, the glands become enlarged 

 and hard and may resemble tumor formation. 



Infectious.— The disease sometimes appears in the form 

 of an epizootic which no doubt is caused by a specific organ- 

 ism. A diplostreptococcus has been isolated from the gland 

 and from Steno's duct during such epizootics. Other organ- 

 isms have also been found but as yet none of them has 

 proved specific. During the course of infectious diseases 

 (distemper, etc.) the parotid is frequently infected resulting 

 in an acute inflammation. Parotitis occurs as a secondary 

 disease in pharyngitis, stomatitis and other local inflamma- 

 tory conditions. Chronic parotitis results from repeated 

 acute attacks or from obstruction to the ducts. 



Pathology.— The acute parotitis in the early stages begins 

 with a swelling, congestion and serous infiltration of the 

 interlobular connective tissue. Later small abscesses develop 

 which become confluent forming one large abscess. In chronic 

 parotitis there is a thickening of the connective tissue and 

 atrophy of the glandular substance which produce a hard, 

 fibrous condition (indurative parotitis). 



Symptoms.— The acute infectious parotitis begins with a 

 swelling in one or both glands, with a collateral edema in the 

 surrounding tissues. The swelling usually develops rapidly, 

 is very painful to the touch and changes the appearance 

 of the head and neck. The head is held away from the 

 affected side or if bilateral is extended. The temperature 

 is elevated (103°-105° F.), the animal shows depression, 

 partial or complete loss of appetite, and mastication is slow 

 and careful. The saliva is usually increased in quantity and 

 runs from the corners of the mouth in strands. In a few 

 days abscesses develop, producing a fluctuating enlargement 

 which discharges reddish colored pus when opened. In 



