754 
DISEASES OF THE METATARSUS. 
DISEASES OF 
I.—DISEASES OF THE TENDONS AND TENDON SHEATHS 
IN THE TARSAL AND METATARSAL REGIONS. 
In the horse, the tendon sheaths, both in the hock and metatarsal 
regions, sometimes become distended, producing conditions of great 
practical importance. * Amongst the most important are— 
(a) Distension of the tendon sheath of the flexor pedis perforans 
produces a swelling on the inner and posterior surface of the hock-joint. 
The sheath begins somewhat above the inner malleolus, passes down¬ 
wards over the capsule of the joint, with which it sometimes communi¬ 
cates, then becomes somewhat flattened, and follows the course of the 
tendon, to appear at the posterior surface of the joint, about two inches 
below which it ends (fig. 279 , b). 
Disease of this sheath is rather frequent in the horse, and occasionally 
produces a hemispherical swelling as large as a child’s head. Sometimes 
it attacks both legs simultaneously, without causing much lameness 
(fig. 282 ). It may in time decrease and even entirely disappear, especi¬ 
ally under proper treatment. In other cases, the portion of the sheath 
lying at the back of the hock-joint becomes enlarged, and may be 
mistaken for curb, for which reason it has been called curb-gall, or soft 
curb. 
In other cases acute inflammation sets in. Bruises and injuries may 
cause septic tendo-vaginitis, accompanied by severe lameness and high 
fever, which sometimes prove fatal. The condition is even more 
dangerous if inflammation extend to the joint (see “ Wounds, Ac., of 
the Hock-joint ”), or produce necrosis of the flexor pedis perforans 
tendon, followed by rupture. Aseptic inflammation of this sheath is 
often caused by drawing heavy loads, and is therefore commonest in 
draught-horses. 
Prognosis. Infectious inflammation of this tendon sheath forms no 
exception to the general rule, and prognosis is therefore unfavourable, 
though cases have been seen to recover. The higher the fever and the 
greater the pain, the less probable is recovery. In aseptic disease, the 
degree of lameness is a fairly safe guide. Occasionally the local 
inflammation becomes so intense that the animal rests the leg con¬ 
tinuously, and throws so much weight on the other foot as to induce 
laminitis; but this is rare, and more frequently the animals are able to 
work, despite considerable swelling. Complete absorption can scarcely 
be expected, though in exceptional cases it occurs in three to six 
months. 
Treatment depends on the nature of the injury. Wounds near 
