INFLUENZA, OF THE HORSE 321 



of infectious pneumonia in no way influences the susceptibility 

 to influenza infection. 



Necropsy. — On postmortem, where the disease has assumed 

 a typical form, the lesions are those identified with 'fibrinous 

 or even hemorrhagic pneumonia, with a marked tendency to 

 gangrene. The extent and distribution of the inflammation 

 varies. In some cases the pneumonia is of the lobar, in others 

 the lobular type. The exudate is usually of a hemorrhagic 

 character. Yellowish-gray areas of necrosis throughout the 

 lung tissues are commonly noted, appearing as encapsuled 

 pus centres or gangrenous foci. 



The pleuritis is serofibrinous; the thorax may contain 

 several gallons of serous exudate. Adhesions between the 

 lung and chest wall (adhesive pleuritis) is a common finding. 

 Empyema of the thorax may be present. 



In the gastro-intestinal tract appear evidence of catarrh 

 and, especially in the small intestine and cecum, inflamma- 

 tory thickenings and ulcerations. 



Symptoms. — Infectious pneumonia of the horse is charac- 

 terized by pneumonia and pleuritis. The pneumonia may 

 assume either the lobar (benign) or lobular (malignant) type. 

 (For details refer to the chapter on Pneumonias of the Horse.) 



Complications. — The most dangerous complications are: 

 (a) Parenchymatous degeneration of the heart characterized 

 by tumultuous heart beat and a rapid, arrhythmic, weak 

 pulse, (b) Nephritis distinguished by scantiness of urine 

 (anuria) and albuminuria, (c) Septicemia, usually following 

 pulmonary gangrene, and recognized by continued high fever, 

 chills, rapid, irregular and weak pulse, and exhaustive diar- 

 rhea, (d) Paraplegia is rarely noted, but is usually a fatal 

 complication, (e) Paralysis of peripheral nerves (facial, re- 

 current) which may persist for several weeks. (/) Swellings 

 of the limbs and pendent parts of the body, seen especially 

 in the latter stages, are troublesome, (g) - Tendinitis and 

 tendovaginitis, (h) Founder, (i) Abortion, (j) Decubitus. 



Diagnosis. — Usually not difficult. Infectious pneumonia 



cannot be differentiated from sporadic lobar pneumonias if 



such occur in the horse. Every case of lobar pneumonia, 



therefore, should be isolated. Obviously this does not apply 



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