DISEASES OF THE HORSE. 411 



stands at rest. After months of lameness the foot is found to be 

 shrunken in its diameter and apparent!}' lengthened; the horn is dry 

 and brittle and has lost its natural gloss, while circular ridges, devel- 

 oped most toward the heels, cover the upper part of the hoof. When 

 both feet are affected, the animal points first one foot, then the other, 

 and stands with the hind feet well forward beneath the bod}^ so as 

 to relieve the fore feet as much as possible from bearing weight. In 

 old cases the wasting of the muscles and the knuckling at the fetlock 

 become so great that the leg can not be straightened; and locomotion 

 can scared}' be performed. The disease generally makes a steady 

 progress without inclining to recover}' — the remission of symptoms 

 in the earlier stages should not be interpreted as evidence that the 

 process has terminated. The complications usually seen are ringbones, 

 sideboncs, thrush, contracted heels, quarter-cracks, and fractures of 

 the navicular, coronet, and pastern bones. 



Treatment. — But few cases of navicular disease recover. In the 

 early stages the wall of the heels should be rasped away, as directed in 

 the treatment for contracted heels, until the horn is quite thin; the 

 coronet should be well blistered with Spanish-fly ointment, and the 

 patient turned to grass in a damp lield or meadow. After three or 

 four weeks the blister should be relocated. This treatment is to be con- 

 tinued for two or three months. Plane shoes are to be put on when 

 the patient is returned to work. In chronic cases the animal should 

 be put to slow, easy work. To relieve the pain, neurotomy may be per- 

 formed—an operation in which the sense of feeling is destroyed in the 

 foot by cutting out pieces of the nerve at the fetlock. This operation 

 in nowise cures the disease, and, since it may be attended with serious 

 results, can only be advised in certain favorable cases, to be deter- 

 mined by the veterinarian. 



SIDEBONES. 



,A sidebone consists in a transformation of the lateral cartilages found 

 on the wings of the coffinbone into bony matter by the deposition of 

 lime salts. The disease is a common one, especially in heavy horses 

 used for draft, in cavalry horses, cow ponies, and other saddle horses, 

 and in runners and trotters, 



Sideboncs are peculiar to the fore feet, yet they occasionally develop 

 in the hind feet, where they are of little importance since they cause 

 no lameness. In many instances sideboncs are of slow growth and, 

 being unaccompanied by acute inflammation, they cause no lameness 

 until such time as, by reason of their size, they interfere with the 

 action of the joint. (Plate XXXII, fig. 4.) 



Causes. — Sideboncs often grow in heavy horses without any appar- 

 ent injury, and their development has been attributed to the over- 

 expansion of the cartilages caused by the great weight of the animal. 



