BONE SPAVIN. 269 



While spavin is forming, there is always lameness, and that frequenrly to a very 

 great degree : but when the membrane of the bone has accommodated itself to the 

 tumour that extended it, the lameness subsides or disappears, or depends upon the 

 degree in which the bony deposit interferes with the motion of the joint. It is well 

 known to horsemen, that many a hunter, with spavin that would cause his rejection 

 by a veterinary surgeon, stands his work without lameness. The explanation is this : 

 there is no reason why an old bony tumour on the outside of any of the bones of the 

 hock, free from connexion with the next bone, and from any tendon, should be at all 

 injurious ; as, for instance, one immediately under e or/, p. 286 : but, from the com- 

 plicated nature of the hock, it is difficult, if not impossible, to be quite sure of the 

 place, or extent, from inspection, of the tumour ; and, besides, the disposition to throw 

 out bone covered by the tumour, may continue and extend to the joint. The surgeon, 

 therefore, cannot be perfectly safe in pronouncing a bone spavin to be of no conse- 

 quence. Horses with exceedincjly large spavins, are often seen that are only slightly 

 lame, or that merely have a stiffness in their gait at first starting, but which gradually 

 goes off after a little motion ; while others, with the bony tumour comparatively 

 small, have the lameness so great as to destroy the usefulness of the horse. There is 

 always this peculiarity in the lameness of spavin, that it abates, and sometimes dis- 

 appears, on exercise ; and, therefore, a horse, with regard to which there is any sus- 

 picion of this affection, should be examined when first in the morning it is taken from 

 the stable. 



If the spavin continues to increase, the bony deposit first spreads over the lower 

 wedge-bones, /, page 386, for these are nearest to its original seat. They are capa- 

 ble of slight motion, and share in every action of the joint, but their principal de- 

 sign is to obviate concussion. The chief motion of the joint, and that compared 

 with which the motion of the other bones is scarcely to be regarded, is confined to 

 the tibia a, and the astragalus h, and therefore stiffness rather than lameness rnay 

 accompany spavin, even when it is beginning to affect the small bones of the joint. 

 Hence, too, is the advantage of these bones having each its separate ligaments and 

 membranes, and constituting so many distinct joints, since injury may happen to 

 some of them, without the effect being propagated to the rest. When the bony de- 

 posit continues to enlarge and takes in the second layer of bones — the larger wedge- 

 bones e — and even spreads to the cuboid bones on the other side, the lameness may 

 not be very great, because these are joints, or parts of the joint, in which the motion 

 is small ; but when it extends to the union of the tibia a, and the astragalus b — when 

 the joint, in which is the chief motion of the hock, is attacked — the lameness is 

 indeed formidable, and the horse becomes nearly quite useless. 



Spavined horses are generally capable of slow work. They are equal to the greater 

 part of the work of the farm, and therefore they should not be always rejected by the 

 small farmer, as they may generally be procured at little price. These horses are 

 not only capable of agricultural work, but they generally improve under it. The 

 lameness in some degree abates, and even the bony tumour to a certain degree dimin- 

 ishes. There is sufficient moderate motion and friction of the limb to rouse the ab- 

 sorbents to action, and cause them to take up a portion of the bony matter thrown 

 out, but not enough to renew or prolong inflammation. It cannot be said that the 

 plough affords a cure for spavin, but the spavined horse often materially improves 

 while working at it. 



For fast work, and for work that must be regularly performed, spavined horses are 

 not well calculated ; for this lameness behind produces great difficulty in rising, and 

 the consciousness that he will not be able to rise without painful effort occasionally 

 prevents the horse from lying down at all ; and the animal that cannot rest well can- 

 not long travel far or fiist. 



The treatment of spavin is simple enough, but far from being always effectual. 

 The owner of the horse will neither consult his own interest, nor the dictates of hu- 

 manity, if he suffers the chisel and mallet, or the gimlet, or the pointed iron, or arse- 

 nic, to be used ; yet measures of considerable severity must be resorted to. Repeated 

 blisters will usually cause either the absorption of the bony deposit, or the abatement 

 or removal of the inflammation of the ligaments, or, as a last resource, the heated 

 iron may be applied. 



The account of the diseases of the hock is not yet completed. It is well known 

 that the horse is frequently subject to lameness behind, when no ostensible cause for 

 25 3 m 



