1006 DISEASES OF THE HOCK. 



probably depends on the acute inflammation which follows assisting 

 union of the diseased surfaces, and not, as Abildgaard and Lafosse 

 thought, on their producing relaxation of the tendon, and preventing 

 it pressing on the diseased joint. Division of the tendon is, therefore, 

 of much less importance than the production of an acute inflammation 

 of the bursa, which extends to neighbouring structures. Dieckerhoff's 

 method is very simple, and quiet horses may be operated on standing. 

 Restive or dangerous animals are cast, with the affected limb lower- 

 most. A twitch is applied, the horse is placed against the wall with 

 the sound limb lifted as in shoeing, and the operator then passes a 

 probe-pointed bistoury into the bursa of the diseased limb. After 

 making sure that the bursa is really opened, the animal is placed 

 in the stable. No after-treatment seems necessary, except to remove 

 excessive granulations by suitable caustics. The wound generally 

 cicatrises in three weeks, and after a further interval of a fortnight 

 the horse can be put to work. 



In many cases this method is successful, but vet others recovery 

 does not occur, while in a certain, though small, proportion acute 

 inflammation of a joint develops, and proves fatal. If in making 

 the incision the operator cut too deeply, which is sometimes un- 

 avoidable, and alight on the boundary between the scaphoid and 

 cuneiform bones, the joint is opened, and purulent arthritis readily 

 follows. It is, therefore, well not to make the incision too far back. 

 Dieckerhoff recommends the centre point between the anterior and 

 posterior borders of the hock. 



The bursa can also be opened with a rather sharply-pointed 

 pyriform cautery. It seems of no importance which method is 

 adopted, though in using the firing-iron care must be taken not to 

 open a joint. The larger the exostosis, the less the danger. 



By bearing in mind that union depends chiefly on the formation 

 of exostoses around the joint, and that the articular surfaces them- 

 selves can only grow together after extensive destruction of the 

 articular cartilage, the reason for seeking to produce extensive bony 

 deposit will be apparent. 



Periosteotomy is the surest method of effecting this, and has been 

 widely recommended in the treatment of spavin. The operations 

 recommended do not differ in any essential point. Peters' method 

 gives excellent results : — The horse is cast on the diseased side, and 

 by a cord passed round the corresponding front limb, the upper hind 

 leg is drawn far enough forward to clear the seat of operation. The 

 hair is then cut away from the inner surface of the hock-joint, midway 

 between its anterior and posterior borders, to the extent of about 



