THB SESAMOIDS.] M ODERN VETERI N AR Y PR ACTI CE. [tub sesamoids. 



THE SESAMOID RONES. 



Sesnmoids is the wiuno ^ivcii to tlioso bones 

 wlvicli are situated at the baek part of the let- 

 lock joint, and are attached, at the upper end 

 or point, to the suspensory ligament, the llexor 

 tendons passing in a concave groove between 

 the two, in their passage to the pastern and 

 coUin-bones. They ta!ce their name from their 

 resemblance to maize, or wliat is perhaps 

 better known as Indian wheat. They have a 

 peculiar elastic movement. Every step the 

 liorse takes, and more especially in the fast 

 trot or gallop, they partially descend, on hia 

 putting his foot to the ground. This is easiest 

 seen in long-pasterned horses, where the fetlock 

 — hair — almost seems to touch the ground. If 

 the animal is over-weighted, this will be dis- 

 tinctly observed. 



The inelastic connection which these bones 

 have below, to the head of the large pastern 

 bone, and the decided elastic connection they 

 have above to the suspensory ligament, clearly 

 show how easy they may be partially, if not 

 altogether dislocated. This is more ready to 

 happen on the inner side, in consequence of 

 the superincumbent weight being thrown on 

 that side when the other foot is in the air, or, 

 to speak more plainly, off the ground. 



The action of the sesamoids being back- 

 wards and downwards, the upper end of the 

 elastic attachment expands ; and this expan- 

 sion, driven to excess, either by over-weight, 

 heavy ground, or when the animal is at the 

 top of his speed, brings the non-elastic attach- 

 ment below into such violent action, that the 

 bones become incapable of contending with it. 

 The consequence of this is, that the liga- 

 mentous attachment is ruptured. This is not 

 an unfrequent case ; for in racing as well as in 

 hunting, the horse sometimes makes a sudden 

 drop, which, in many instances, is taken for 

 what is termed "breaking down;" but it is 

 no such thing. It is the rupture of a portion 

 of the lower attachment of the sesamoid bones, 

 principally on the inner side — when this side of 

 the fetlock joint will appear much larger than 

 the outer. If the hand is passed down the leg. 



over the part, pressing gradually aa it is moved 

 down, the seat of partial dislocation will at 

 once bo discovered, not only by the projection 

 of the upper end of the bone, but by tho 

 ))aiti whicli tho horse will show ht:nMo!f to bo 

 Builering on pressing tho most prominent part 

 of the bone. 



This accident has occurred, and tho inflam- 

 mation run BO very high, that the whole of 

 the leg, up to tho knee, has been swollen to 

 such an extent, that the disease has been taken 

 for strain in the back sinews, when, iu fact, it 

 entirely arose from this partial dislocation of 

 one of the sesamoid bones. 



The curative treatment of this disease always 

 involves a considerable space of time ; although 

 the time might be very much shortened if per- 

 sons discovered the part affected at once. All 

 liniments, or blisterings, will never perma- 

 nently remove it, though they may relieve it ; 

 but when the horse is brought into use again, 

 he becomes lame. On this account recourse 

 must at once be had to firing; not in a partial 

 manner, but it must be extended a little above 

 the bifurcation of the suspensory ligament — 

 say about an inch, and as far as half-way down 

 the large pastern bone. Fire all round the 

 leg completely; then lay lightly on it — 



Cantharides 

 Host's Lard . 



4 drachms. 

 2 oz. 



Take the necessary precaution to prevent tho 

 animal either rubbing or biting the leg. "Whilst 

 he is in the stable, give him bran mashes cold, 

 and 



Cape Aloes 4 draclims. 



Ginger 1 do. 



^lix, to form a ball, with soap. 



If he should be costive, which is sometimes 

 the case, repeat the medicine before he has a 

 run at grass, which he ought to have in about 

 nine days after the firing. The accompanying 

 explanatory engraving, showing a section of 

 tho foot, its bones and ligaments, with the 

 appearance of the hoof in a healthy and 

 diseased state, will greatly assist the reader in 

 obtaining a knowledge of tho anatomy of that 

 important member of the horse. 



185 



