352 ACUTE GENERAL INFECTIOUS DISEASES 



great effusion); (c) pneumonia centralis (sudden dyspnea 

 with rise in the temperature during the course of the disease) ; 

 (d) hemorrhages (epistaxis, bloody pleural exudate) ; (e) tem- 

 perature continues high for over a week or is remittent in 

 character; (/) diarrhea; {g) lung gangrene; (h) brain symp- 

 toms. 



Treatment. — See Pneumonias of the Horse. 



PURPURA HEMORRHAGICA. PETECHIAL FEVER. 



Definition. — Purpura hemorrhagica is an acute, non- 

 contagious disease the result of a toxemia usually developing 

 as a sequel to a specific infectious disease. It is charac- 

 terized by marked edematous swellings of the head and limbs 

 and petechias in the mucous membranes and internal organs. 



Occurrence. — ^Frequent in the horse. Cases are said to 

 occur in the ox and the dog. The disease usually is seen to 

 follow in the wake of an outbreak of influenza or strangles, 

 individual cases during convalescence developing the symp- 

 toms which typify the condition. It may also be a 'sequel to 

 other debilitating diseases, especially if the patient has been 

 kept in unsanitary surroundings and poorly nourished. It is 

 rare in horses under two years old, but may attack aged 

 individuals. 



Etiology. — Purpura in horses, as noted, is a secondary dis- 

 ease, and is probably always associated with a hidden pus 

 pocket or an area of necrosis somewhere on or in the body of 

 the animal attacked. It is, therefore, most apt to follow dis- 

 eases or conditions attended by pus formation or necrosis 

 (strangles, pharyngitis, empyema of facial sinuses, suppura- 

 tive tooth diseases, internal abscesses, old castration wounds, 

 necrosis of the skin) . The disease is not transmissible either 

 by inoculation or blood transfusion; there are no specific 

 organisms found in the blood. Very probable, therefore, is 

 the theory that toxins, originating in a primary pus or necrotic 

 focus, absorbed by the blood, in time intoxicate the animal 

 the resistance of which has been lowered by disease, unhy- 

 gienic environment and poor food. While the blood itself 

 seems to suffer little change in physical properties, the 



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