LAMENKSS: ITS CAUSES AND TREATMENT. 353 



than has been supposed. Many observations and careful dissections 

 have convinced us that fractures' of these little bones have been often 

 mistaken for specific lesions of the numerous 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 my post-mortem examinations I 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. 



Cause. — From whatever cause this lesion may arise, it can hardly 

 be considered 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 acquires 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 at- 

 tacked, at short intervals and without any obvious cause, seems to 

 prove the existence of some latent, morbid cause which has been unsus- 

 pectedly incubating. It is not peculiar 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. 



Symptoms. — The general fact is reported in the history of most 

 cases that it makes its appearance without premonition in animals 

 which, after enjoying a considerable period of rest, are first exer- 

 cised 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 continue 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, upon com- 

 ing 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 rests upon this part, the skin of 

 which may have remained intact or may have been more or less exten- 

 sively lacerated. It seldom happens that more than one toe at a 



36444°— 16 ^23 



