PURPURA HEMORRHAGICA— PETECHIAL FEVER 323 



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 

 walls of the bloodvessels, especially the capillaries, become 

 porous or rupture, allowing the blood to escape into the sur- 

 rounding tissue. Thus smaller petechia? or more extensive 

 ecchymoses are produced. From the larger veins the transu- 

 dation of serum leads to the characteristic swellings. 



Symptoms. — Petechia? in the mucous membranes of the 

 head. The hemorrhagic spots vary in size from a hemp seed 

 to a bean. Sometimes on the nasal mucosa (septum and 

 turbinates) the areas assume the form of stripes or striations, 

 the membrane being swollen. The petechia? have a purple 

 color. Sometimes ulceration is noted. There is nasal dis- 

 charge of a yellowish or reddish serum or fluid blood. In 

 the eyelid conjunctivitis is present with petechia? and slight 

 sanguineous discharge. The mucous membranes of the 

 mouth, though more rarely, may also be involved. 



Swellings of the skin usually appear with the petechia? or 

 follow in a day or two. These are often at first isolated, flat- 

 tened, urticaria-like tumefactions from the size of a pigeon's 

 egg to that of a grapefruit, and larger by confluence. They 

 are firm or edematous on palpation. More common, however, 

 are diffuse swellings of the lower portion of the head, ventral 

 part of the thorax and abdomen, udder, prepuce, or scrotum 

 and limbs. In the regions of the nostrils and lips they com- 

 monly begin and rapidly extend upward toward the eyes. 

 The swellings are firm, and, especially at the flexion of joints, 

 the overlying skin cracks open and a yellow, viscid, serous 



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