319 



forming tbe office of retentiou unaided. Local treatment by batlis and 

 fomentations will do the rest. It may be months before there is any 

 mitigation of the lameness. 



Fracture of the sesamoid hones. — This lesion has been considered by 

 veterinarians, erroneously, we think, one of rare occurrence. We be- 

 lieve it to be more frequent than has been supposed. Many observa. 

 tions and careful dissections have convinced us that fractures of these 

 little bones have often been mistaken for specific lesions of the numer- 

 ous ligaments that are implanted upon their superior and Inferior parts, 

 and which have been described as a " giving way " or " breaking down " 

 of these ligaments. In our 2^ost mortem examinations we have always 

 noted the fact that when the attachments of the ligaments were torn 

 from their bony connections minute fragments of bony structure were 

 also separated, though we have failed to detect any diseased process of 

 the fibrous tissue composing the ligamentous substance. 



From whatever cause this lesioji may arise, it can hardly be consid- 

 ered as of a traumatic nature, no external violence having any apparent 

 agency in producing it, and it is our belief that it is due to a peculiar 

 degeneration or softening of the bones themselves, a theory which ac- 

 quires plausibility from the consideration of the spongy consistency of 

 the sesamoids. The disease is a peculiar one, and the suddenness with 

 which different feet are successively attacked, at short intervals and 

 without any obvious cause, seems to prove the existence of some latent 

 morbid cause which has been nnsuspectedly incubating. It is not pe- 

 culiar to any particular class of horses, nor to any special season of the 

 year, having fallen under our observation in each of the four seasons. 

 The general fact is reported in the history of a majority of cases that it 

 makes its appearance without premonition in animals which, after en- 

 joying a considerable period of rest, are first exercised or put to work, 

 though in point of fact it may manifest itself while the horse is still idle 

 in his stable. A hypothetical case, in illustration, will explain our 

 theory : 



An animal which has been at rest in his stable is taken out to work 

 and it will be presently noticed that there is something unusual in his 

 movement. His gait is changed, and he travels with short, mincing 

 steps, without any of his accustomed ease and freedom. This may con- 

 tinue until his return to the stable, and then, after being placed in his 

 stall, he will be noticed shifting his weight from side to side and from 

 one leg to another, continuing the movement until rupture of the bony 

 structure takes place. But it may happen that the lameness in one or 

 more of the extremities, anterior or posterior, suddenly increases, and it 

 becomes evident that the rupture has taken place in consequence of a 

 misstep or a stumble while the horse is at work. Then, ui)on coming to 

 a standstill, he will be found with one or more of his toes turned up — he 

 is unable to place the affected foot flat on the ground. The fetlock has 

 dropped and the leg xests uxion this part, the skin of which may have 



