80 PRINCIPLES OF VETERINARY SURGERY 



purulent infection, and septicsemia are among the conditions 

 that may result from them. 



SYMPTOMS. — The clinical pictures produced by throm- 

 bosis will of course vary according to the location, the extent 

 of the obstruction, and the character of the infection if any 

 exists. The choking up of the blood vessels of the skin "of 

 the heels of horses following virulent infections and resulting 

 in a circumscribed gangrene of the integument is an example 

 of the effects of -thrombosis of strictly bacterial origin. 



Thrombosis in animals always produces severe pain in 

 the affected region. When a radial,- brachial, tibial, ferrioral 

 or iliac vessel is the seat of the obstruction, the leg becomes 

 oedematous and extremely painful to the touch; and' very 

 grave systemic disturbances immediately follow. If the ob^ 

 struction is wide-spread death will often result from pain and 

 exhaustion before the co-lateral circulation is sufiUciently 

 augmented to offer adequate compensation. When the acute 

 stage is survived and the clot is replaced with connective tis- 

 sue, the pain may only appear during exercise, and then 

 pi-omptly subside with rest. Smaller arteries of the legs may 

 become the. seat of thromboses and cause very excruciating 

 pain without producing any swelling. If buried deeply in the 

 muscles palpation may fail to locate the seat of the lesion in 

 spite of the excruciating pain. In the acute case, and also 

 during seizure in the chronic case the leg will support little or 

 no weight, the respirations will be augmented, and the body 

 bathed with perspiration. 



A certain well known race-horse began to show signs of distress in' one 

 hind leg after each work-out of one-half to one mile. During rest and dur- 

 ing short runs nothing abnormal was noticeable, but with each long run a 

 marked lameness developed with great regularity. With each seizure there 

 was trembling, perspiration, distress and severe lameness in the left hind leg. 

 The horse was treated in different joints of the legs during two years, at 

 the end of which time an effort to speed him provoked the very same symp- 

 toms, unpalliated and unaltered. An examination of the iliacs through the 

 rectum revealed a hard formation at the aortic quadrification, and absence 

 of perceptible pulsations in the left external iliac. The left internal iliac 



