DISEASES OF THE RESPIRATORY TRACT 5 1 



In the early part of the disease friction sounds, 

 caused by the dry, inflamed membranes rubbing 

 against each other, are heard on placing the ear 

 against the chest walls. Later the collection of 

 fluid around the lungs may deaden all lung sounds 

 toward the lower part of the chest. In this stage 

 of the inflammation, if the fluid forms in large 

 amounts, the respirations become very labored. 



The symptoms are mild if the pleurisy is local- 

 ized — that is, only a part of the membrane inflamed. 

 A lameness in both front limbs and stiffness in 

 moving about are the most noticeable symptoms in 

 this form of the disease. 



In chronic pleurisy the hog is usually very weak 

 and depressed. It is frequently seen lying on its 

 side, and unable to get up and walk about. The 

 inflammation may extend to the heart and its cov- 

 erings, and the symptoms of these diseases are 

 manifested. 



The course of acute pleurisy is one or two weeks. 

 The chronic form may run a course of several 

 weeks. The prognosis is very unfavorable. 



Lesions. — The serous membrane is thickened 

 and inflamed. Its surface is roughened and cov- 

 ered with membranous growths and fibrous bands 

 that attach the lungs to the chest walls. The lat- 

 ter condition is a constant lesion in old, chronic 

 inflammations. In the exudative form of the dis- 

 ease (hydrothorax) more or less fluid is present in 

 the chest cavity. This may be yellowish or reddish 

 in color and hold in suspension fibrous flakes or 



