354: HEALTH AND DISEASE 



SPEAIN OF THE BACK SINEWS 



The accidental overstretching and rupture of the fibres composing the 

 tack sinews is of common occurrence, and is usually designated break- 

 down. 



The structure most frequently implicated in this accident is a short 

 ligament (fig. 366), which proceeds from the upper and back part of the 

 canon-bone, and joins the flexor pedis or main tendon of the leg about 

 three inches below the knee. The seat of injury is invariably at the point 

 of union of the two parts. 



Horses of the heavy breeds and others engaged on the turf are specially 

 liable to the mishap in consequence of the severity of their work. 



Causes. — Horses light of bone, and whose sinews lack size and 

 strength, are more predisposed to this disease than others of stouter 

 build, as are also those with big, heavy frames and small limbs. The 

 exciting causes are heavy draught, slipping and sliding on smooth pave- 

 ment, and severe efforts in galloping and jumping, particularly under cir- 

 cumstances of fatigue, as at the end of a quickly-run race or steeplechase, 

 when the muscles are tired and the weight of the body is forcibly thrown 

 on the passive structures. 



Symptoms. — As a result of this accident an enlargement mostly makes 

 its appearance in the course of the tendons, about three inches below the 

 knee. It is sometimes small and hardly perceptible, while at others it may 

 reach the size of a walnut, or even larger, and extend a considerable 

 distance downwards. When pressed, the horse winces and lifts the leg 

 sharply from the ground. The part, moreover, is hot and inflamed. In 

 standing, the heel of the foot is slightly raised, or the leg may rest on the 

 toe. The amount of lameness will depend upon the severity of the strain. 

 In progression the horse moves short, and imposes the weight maiidy on 

 the front part of the foot to relieve the injured part from traction. 



Treatment. — In this connection it is important that the injured 

 structure should, as far as possible, be placed in a state of rest. For 

 this purpose the ordinary shoe will require to be removed at once and 

 replaced by one having a thick or wedge heel. Hot fomentations should 

 then be applied for an hour or two, and followed by the continuous use 

 of hot flannel bandages to the leg. A dose of physic and absolute quiet 

 must also be enjoined. 



When the inflammation and pain have been in a large measure reduced, 

 hot fomentations may be changed for cold water irrigation and cold linen 

 bandages. It may be that in slight cases these, with a short period of rest, 



