LAMENESS AND DISEASES, ETC. 177 



retained in their places, become bulged or sprung forward. 

 {Compare Fig. 72 with perfect knee of skeleton, Fig. 2.) 



In many cases the formation of the animal, such as undue 

 length of limb from the knee to fetlock, is a natural predisposi- 

 tion to weakness at knee ; also, abnormal presentation at time 

 of foaling where knees are doubled under the body, may produce 

 a similar tendency. 



Young horses subjected to an excess of hard pulling before 

 they are seasoned or matured, are most liable to iujure their 

 knees in this manner. Care should therefore be taken in work- 

 ing: them that their limbs are not overtasked while under the 

 age of seven years. 



Horses employed in constant " up-hill "' work, where the 

 stress upon the knee is continued and severe, or in sufi'ering 

 them to stand in stalls where the slope is considerable and the 

 floor hard, necessitating exertion in the muscles of the leg, and 

 keeping the ligaments constantly in a tense state, will expose 

 them to a deformity in their knees, by their leaning or bowing 

 out in consequence of the ligaments and tendons becoming 

 weakened. When the proper angle of the foot is destroyed, as 

 is most usually produced by improper shoeing, such as having 

 high toes and low heels, causing the lower pastern to bear down 

 upon the navicular bone, which in turn presses back against the 

 flexor perforans, will produce an over distension of the muscles ; 

 and similarly, sore or bruised heels will cause a constant leaning 

 forward on the knees to relieve the pressure on other parts, and 

 thus produce this defect ; or, should the foot even be properly 

 pared, and the shoe then applied be thick at the toe — the heels 

 of the hoof being low — the efiect of always ascending would be 

 the same, and result in the malformation of which we treat ; or, 

 if the shoe is too short — indeed, any mode of shoeing that will 

 unbalance the foot, may cause the knees to spring forward. 



"When the disease becomes chronic, and the ligaments and 

 tendons so much relaxed as to be no longer able to respond to 



