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DADDS VETERINARY MEDICINE AND SURGERY. 



Thoeough-pin. 



The seat of tliorougli-pin is between the popliteous (fig. 2) and 

 the point of the hock, near where the tendon is severed, as shown 

 in the accompanying engraving. The disease is called thorough- 

 pin, simply because the fluid contained in the bursal sac can be 

 squeezed from one side to the other. 



VIEW OF SOME OF THE DEEP-SEATED MUSCLES IN THE REGION OF THE HOCK AS» 8TIF».«. 



Explanation.— 1, Popliteous; 2, Flexor pedis accessorius ; 3, Flexor metatarsi niagnufl; 

 4, The tendon, common both to the flexor metatarsi and extensor pedis ; 5. The groove 



"* which the extensor plays. 



Symj^toms. — The disease is similar to bog spavin and wind -galls; 

 namely, enlargement of a synovial sac. It seldom if ever lames 

 a horse, yet, when large, is apt to interfere with the free action of 

 the joint. 



In former years it was customary to open thorough-pins by 

 means of a lancet, in view of evacuating the fluid ; but many fatal 



