biSEASES OP RESPIRATORY ORGANS 16d 



possible to clinically diagnose hydrothorax until the advanced stages. 

 There will be difficult respiration, and if the thoracic wall is not too 

 thick a splashing sound may be noted synchronous with the heart- 

 beat. An exploratory puncture with a small hypodermic needle will 

 usually result in the discharge of serous fluid. 



Treatment. — Temporary relief may be obtained by withdrawing 

 the fluid from the cavity, but permanent results cannot be expected 

 until the primary causative factor has been removed or overcome. 



HEMOTHORAX 



Hemothorax is a condition of the escape and accumulation of blood 

 in the thoracic cavity. It is not a recognized clinical entity, par- 

 ticularly in relation to swine, yet it does occur, and is sometimes 

 observed by inspectors of meat-food products. 



Etiology. — This condition is observed in swine that have been 

 transported to market, and the affected swine at the time of autopsy 

 show evidence of having been injured, probably while in transit. 

 The injury may be a puncture, wound, or a contusion. 



Lesions. — Accumulation of blood in the thorax characterizes this 

 condition. The blood may be coagulated, but it usually remains in 

 the fluid state until the thorax is opened. The quantity of blood 

 Vfill depend upon the nature of the injury and the length of time 

 clasping after its infliction. If the hemorrhage is of long standing, 

 pigmentation of the pleura may be the only evidence remaining. 



Symptoms. — The majority of animals affected with hemothorax 

 show no symptoms. There may be paleness of the visible mucous 

 membranes, weakness of the animal, and difficult breathing due to 

 compression of the lung, but these symptoms are evident only in 

 those cases in which the hemorrhage is extensive. 



Treatment. — Medicinal treatment is of no value. 



PNEU M OTHORAX 



This is characterized by the accumulation of air in the thoracic 

 cavity, a condition extremely rare in swine. The usual cause of 

 the conditioji is injury in which the lung tissue is lacerated. The 

 injury most frequently consists of fracture of a rib occasioned by 

 improper handling in transportation. 



The principal lesion observed consists of the primary injury. The 

 thorax is found to contain air, and tlie lung is compressed. 



