92 PRACTICE OF EQUINE MEDICINE. 



ing gruel in a pail, and when the animal is left alone he will often 

 suck it up, 



Tetanine (anti-toxine) has been used with varying success, but 

 up to the time of writing it cannot be relied on. Probably in the 

 near future it may be improved so as to produce the desired effect. 



4. CONSTITUTIONAL DISEASES. 



PURPUEA H^MOERHAGICA. 



Name the synonyms. 



Purpura, petechial fever of horses, dropsy, anasarca, morbus 

 maculosus, scarlatina. 



Define Purpura. 



This is a constitutional disease, having its origin in the blood 

 and capillaries, and characterized by petechial spots on the mucous 

 membranes, and by swellings under the shin, the result of sanguine- 

 ous effusion. 



What is the pathology? 



Extravasations of the blood from the vessels are found in the 

 interstices of the various organs, as the lungs, spleen, kidneys, and 

 the subcutaneous tissue; there is a Jelly-like mass, and the blood is 

 darker than normal and more fluid. 



Similar conditions exist on the skin and mucous membranes, 

 associated with hemorrhage on the free surface. 



Give the aetiology of this affection. 



It may occur as a primary disease, but is seen mostly as a 

 secondary condition. 



The real cause is not well understood, and, although probably 

 due to bacteria, one fact is obvious — that it follows debilitating 

 conditions, as influenza, strangles, pharyngitis, intestinal catarrh, 

 suppurative lymphangitis, pneumonia, pleurisy. Many cases, how- 

 ever, make their appearance without previous sickness. 



Embolism and thrombosis are said to be causes; also, a dis- 

 ordered condition of the vasomotor system. Bad drainage, dark, 

 damp stables, poorly ventilated, seem to favor its development. 



