122 Surgical Diseases and Surgery of the Dog 



garded as an indication of the existence of tuberculous nodules, in 

 which case the animal becomes a menace to its kind, and possibly 

 to the human race. Tuberculin should always be injected to con- 

 firm the suspicion. Inoculation tests may also be made on rabbits 

 and cavies, but no reliance is to be placed upon them in case of a 

 negative result, for the reason that old effusions are sometimes 

 completely sterile, while the nodules may contain large numbers 

 of bacilli. 



A not infrequent sequel to pleurisy is atelectasis or pulmonary 

 collapse, caused by peripheral compression of the lung proceeding 

 from pleural or pericardial effusion. The presence of the fluid 

 interferes with the inspiration of air, and the pressure gradually 

 forces out the residual air in the alveoli. It is usually confined 

 to part of a lung, but may involve the whole. 



Treatment. At the outset of the disease counterirritation in 

 the form of mustard plasters should be applied, and the costal and 

 sternal regions protected by a flannel chest jacket. After effusion 

 has taken place medical measures are directed towards producing 

 purgation and diuresis and sustaining the heart. The fluid is 

 best removed by thoracentesis, and this operation should always be 

 resorted to when dyspnea is intense. 



Purulent Pleuritis. This disease is always of pyogenic ori- 

 gin through accidental penetration of microorganisms (staphy- 

 lococci and streptococci) into the pleural sacs. Delafond regarded 

 traumatism as a frequent cause. A violent blow, such as by the 

 hoof of a horse or by the horn of an ox, resulting in fracture of 

 one or more ribs, may so enfeeble the resisting power of the tissues 

 as to permit of incursions by microorganisms. Another manner 

 in which the disease may originate is through perforation of the 

 esophagus by foreign bodies, such as animal or fish bones. In one 

 instance Siedamgrotzky found an ear of wheat in the left pleural 

 sac, the channel of entry of which could not be determined in 

 spite of careful search. In another, Weber found a spikelet of 

 rye which had perforated a bronchus. Leclerc saw a fatal purulent 

 pleurisy caused by the discharge of pus from an abscess in the 

 lung resulting from the presence of a briar thorn. Cancerous 

 tumors are also productive of purulent lesions. 



Symptoms and Diagnosis. The symptoms are fever with a tem- 

 perature of about 105° F., profound prostration, arched back, a slight 



