TUBERCULOSIS OF DOGS AND CATS 621 



Pathogenesis.— Most of the cases no doubt result from 

 association with tubercular human beings, or contact with 

 infected rooms, etc. It may also result from ingesting meat 

 containing the bacilli. 



Pathology.— Two distinct types are found on necropsy: 

 (a) Pulmonary form, and (6) digestive form. 



(a) In the pulmonary form the lungs show caseous foci, 

 or small miliary nodules. A chronic, indurative broncho- 

 pneumonia or a chronic interstitial pneumonia is frequently 

 found. Adhesions are common between the lungs and 

 parietal pleura. Aside from these lesions there are very often 

 present edema and emphysema of the lungs, bronchitis and 

 bronchiectasis. The pleura often shows evidence of a serous 

 or serofibrinous pleuritis with considerable fluid present in the 

 thoracic cavity; or in other cases a dry, granular adhesive 

 pleuritis in which the parietal and visceral pleura are adherent. 

 Numerous small nodules are often found on the pleura. The 

 bronchial lymph glands are more or less enlarged. 



(b) The intestinal lesions are mainly in the mesenteric 

 lymph glands, which are enlarged ; the walls of the intestines 

 show miliary tuberculosis, particularly on the serous covering ; 

 the liver usually presents similar lesions. The spleen and 

 kidneys often show miliary tuberculosis. The cadaver in 

 general shows evidence of cachexia and emaciation. 



Symptoms.— The disease usually runs a chronic course the 

 symptoms developing gradually. General emaciation is 

 apparent in spite of a fairly good appetite, the animals become 

 easily exhausted, are dyspneic (lung form), and weak. After 

 emaciation begins to be a prominent symptom, the form of the 

 disease, whether pulmonary or intestinal, will assert itself. 

 The pulmonary form is characterized by a short, dry cough, 

 which later becomes moister and is accompanied by a dis- 

 charge of a mucopurulent secretion which in most cases is 

 swallowed. The respirations grow labored; dry or moist 

 rales are heard on ausculation. Percussion reveals areas of 

 flatness, and usually hydrothorax. An atypical fever is 

 present during the course of the disease. In the intestinal 

 form the symptoms of chronic intestinal catarrh are most 



