322 ACUTE GENERAL INFECTIOUS DISEASES 



to all lobular pneumonias, especially foreign body, medicinal, 

 or hypostatic. 



Course. — When the pneumonia assumes the lobar type with 

 mild pleuritis the course is about two weeks. If, however, 

 the lobular form of pneumonia with pronounced bilateral 

 pleuritis is present the course is prolonged for weeks, with 

 remissions and exacerbations, either ending finally in death 

 or leaving the patient permanently wind-broken (pleural 

 adhesions; roaring). (See Lobular Pneumonia.) 



Prognosis. — The mortality is 1 to 4 per cent. The following 

 factors are important in the prognosis; they are all grave 

 symptoms: (a) Heart paralysis (rapid, empty pulse, venous 

 pulse) ; (b) extent of pneumonia and pleuritis (bilateral with 

 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 sequela to a specific infectious disease. It is characterized 

 by marked edematous swellings of the head and limbs and 

 petechise 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 sequela 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 



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