OF VETERINARY MEDICINE. 83 



effusion into the pleural cavity, i. e., providing adhesions do not 

 form. This effusion is called hydrothorax — water in the chest. 

 The lungs float up until the animal cannot breathe and he dies 

 from asphyxia. If the extent of oedematous pleura is not too 

 big, and the inflammation subsides before the chest is more than 

 one-third full, absorption will take place and the animal will re- 

 cover. 



The special pathology of pleurisy is just as typical as in any 

 other inflammation. All fatal cases of pleurisy die in the second 

 half of the third stage. If the animal goes on to the fourth 

 stage, the stage of absorption, he recovers. 



Hydrothorax is dangerous or not according to the amount 

 of serum in the chest. Its quantity depends upon the extent of 

 the inflammation and its severity. In most cases the liquid in 

 the cavity is serum, but it may be purulent and the condition 

 is called euipyema. Empyema is much more serious than hydro- 

 thorax. 



Symptomatology. — Pleurisy is ushered in with rigor which 

 is more or less severe. As a rule it is less severe than the chill 

 of bronchitis or pneumonia. The coat of the animal is staring 

 and he has a rise of temperature. The congestion of the first 

 stage is painful ; the horse is restless, he paws, gets up and down, 

 and sweats. These symptoms are often mistaken for those of 

 colic. This m»istake does no harm except that it delays the 

 proper treatment. This stage lasts a few hours when the horse 

 becomes more quiet, he is disinclined to move and breathes with 

 care. His pulse is increased and begins to get hard ; ribs are 

 fixed ; abdominal muscles contracted, producing a line to the 

 point "f the elbow. This depression is called the pleuritic line, 

 which as a rule we do not get in any other disease. 



As further symptoms w^e find the elbows turned out; ears 

 drooping and cold ; legs cold and the expired air cold. The horse 

 breathes as little as he can because it is painful, and the air does 

 not reach the vesicles. Auscultation reveals friction sounds over 

 the affected part, like two dry surfaces rubbing together. If you 

 force the fingers between the ribs, it will cause pain and the 

 horse will flinch and grunt. If you move him he will grunt. This 

 grunt in acute diseases always indicates pleurisy in the horse; 



