8 June, [907.] 



Lameness in Horses 



379 



lateral cartilages Avhich latter are thereby ke]:)t continuously under siriiin. 

 To enable the cartilages to withstand this continuous strain Nature 

 strengthens them bv a deposition within their substance of bony matter o~ 

 rather b\ actually transforming them into^ bone. (See Figs. 49 to 53.) 

 The process In which this transformation takes pb.ce is an infiammatorv 

 c:ne and it is during the activity of the inflammation that lameness occurs. 

 The inflammation, once started, will continue as long as the cause con- 

 tinues to act ; and hence, except the horse is rested and shod flat so as 

 to give frog pressure, the bone formation goesi on and tlie sidebone continues 

 to grow larger. In support of the contention that calkin-shoeing is the 

 chief cause of sidebone it may be added that it is not until draught horses 

 are shod and put to work on the roads that the conditions develop. As 

 long as the\- remain unshod or are kept to ploughing or other work on soft 

 ground (even if shod) sidebones are never formed. 



Another cause likely to induce inflammation of the lateral cartilages 

 w hereby sidebones mav result is external \-iolence or injury such as max be 

 sustained bv cart-horses bv the dropping of the cart stiafts when unyoking 

 in such a manner as to hit the sides of the feet. Stepping on the inside 

 of one foot with the other font or treads from other horses often produce 



\ 



V. 



Fu 



Shovvinj; variet\- in sliape ot sidebones. (After Hayes. 



su<-h an injur\-. and ( ajitain Haves has recorded that horses sliipped fron 

 Australia to India often develop sidebone as a result of injury sustained 

 ii\ the tread of other horses when over-crowded on board ship. 



Symptoms. — The natural elasticity or springiness on pressure of the 

 cartilages at the coronet on the inside and outside of the foot is lost, an:', 

 instead, a hard unyielding bony enlargement may be felt. The absence of 

 springiness may be best ascertained when full weight is sustained on the 

 foot by thumb pressure applied in the manner described at page 156. Tn 

 some rare cases the lameness precedes the formation of bone and, bemg 

 inflamed, the part will be hot to the touch a;nd pain will be evinced on 

 pressure. During progression the animal moves with a short stilty stejj 

 and has a tendency to stumble from an attempt to 4avoid shock on the heels. 

 " Going on the toe " is marked and is evidenced by the wearing away of 

 the shoe at the toe. 



Treatment. — Rest is necessary. With the object of relieving the ten- 

 sion on the lateral cartilages bv getting the frog to come to the ground and 

 so assist in weight bearing the shoe should be removed; or, if the frog is 

 well developed a bar shoe should be put on so as to get frog pressure. 



