316 DISEASES OF THE IIOESE. 



the animal is not worth a long and uncertain treatment, a competent 

 veterinarian should be engaged to perform double neurectomy, high 

 or low, of the plantar nerves, or neurectomy of the median nerve as 

 indicated by the seat of the lesion. 



SIDEBONES. 



On each side of the bone of the hoof — the cofRnbone — there are 

 normally two supplementary organs which are called the cartilages 

 of the foot. They are soft, and though in a degree elastic, yet some- 

 what resisting, and are implanted on the lateral wings of the coffin- 

 bone. Evidently their office is to assist in the elastic expansion and 

 contraction of the posterior part of the hoof, and their healthy and 

 normal action doubtless contributes in an important degree to the 

 perfect performance of the functions of that part of the leg. These 

 organs are, how^ever, liable to undergo a process of disease which re- 

 sults in an entire change in their properties, if not in their shape, by 

 which they acquire a character of hardness resulting from the de- 

 posit of earthy substance in the intimate structure of the cartilage, 

 and it is this change, when its consummation has been effected, that 

 brings to our cognizance the diseased growth wdiich has received the 

 desigTiation of sidebones. They are situated on one or both sides of 

 the leg, bulging above the superior border of the hoof in the form of 

 two hard bodies composed of ossified cartilage, irregularly square in 

 shape and unyielding under the pressure of the fingers. 



Cause. — Sidebones may be the result of a low inflammatory condi- 

 tion or of an acute attack as well, or may be caused by sprains, bruises, 

 or blows; or they may have their rise in certain diseases affecting the 

 foot proper, such as corns, quarter cracks, or quittor. The deposit of 

 calcareous matter in the cartilage is not alwaj^s uniform, the base of 

 that organ near its line of union with the coffinbone being in some 

 .cases its limit, while at other times it is diffused throughout its sub- 

 stance, the size and prominence of the growth varying much in 

 consequence. 



Symptoms. — It would naturally be inferred that the degree of 

 interference with the proper functions of the hoof which must result 

 from such a pathological change would be proportioned to the size of 

 the tumor, and that as the dimensions increase the resulting lame- 

 ness would be the greater in degree. This, however, is not the fact. 

 A small tumor while in a condition of acute inflammation during the 

 formative stage may cripple a patient more severely than a much 

 larger one in a later stage of the disease. In any case the lameness is 

 never wanting, and with its intermittent character may usually be 

 detected W'hen the animal is cooled off after labor or exercise. The 

 class of animals in Avhich this feature of the disease is most fre- 



