628 OSSIFICATION OF THE LATERAL CARTILAGE. SIDE-BONE. 
after severe exertion, but tends to disappear with rest. Complete 
recovery is, however, very rare once the disease has become well 
developed. 
Diagnosis is seldom difficult, the character of the lameness being 
often sufficient, provided there is no other disease of the flexors or 
chronic navicular disease. The swelling is less to be relied on. Thus 
exostoses sometimes occur on the sesamoid bones, particularly on their 
lateral surfaces, without causing a trace of lameness, and, from their 
symmetrical appearance in both limbs, often give the impression of 
being congenital. Before delivering a prognosis, it is best to thoroughly 
examine the flexor tendons, and to make sure whether the fetlock-joint 
can be fully flexed. 
Treatment. During the stage of acute inflammation, and particu¬ 
larly when the flexor tendons exhibit recent swelling, the animal should 
be rested, and the fetlock-joint, as far as possible, fixed by a firmly 
applied bandage, which may be moistened with warm water, or, in case 
of great pain, with a continual current of cold water. Good results 
sometimes follow firing and blistering, though six to eight weeks’ rest 
is then necessary. Old-standing cases are not often benefited by such 
treatment. Neurectomy is the only means of removing lameness ; and, 
considering the seat of disease, it is better to divide the median than the 
plantar nerve. 
YIII.—OSSIFICATION OF THE LATERAL CARTILAGE. 
SIDE-BONE. 
The term side-bone is applied to a condition in which the lateral 
cartilages of the foot become partially or entirely ossified. The wings 
of the pedal bone are prolonged backwards and upwards by two plates of 
cartilage about a quarter of an inch thick and approximately rhomboidal 
in shape, each of the faces being some three inches in length (see 
figs. 245 and 246). They are only found in solipeds. Under the action 
of the body-weight the plantar cushion, to which they are attached, 
alternately expands and contracts, and so long as the cartilages remain 
normal they respond to this movement. When ossification commences, 
however, movement in the anterior portions is limited, and the posterior 
sections of the cartilage, which usually resist disease for the longest 
period, tend to be excessively displaced at each step. This aggravates the 
already existing inflammation in the anterior parts, and causes pressure 
on the sensitive structures of the back of the foot, producing well-marked 
lameness. For this reason the disease is often progressive, and is much 
more serious in animals with upright, narrow heels, where the horn 
cannot yield, than in the opposite formation. 
The entire cartilage does not always become ossified, however; nor do 
