712 
DISEASES OF THE HOCK. 
fracture was caused by mounting a cow, and in the calf, by falling into a 
ditch. The same causes which produced rupture of the Achilles tendon 
may of course lead to fracture of the os calcis. 
The symptoms and course closely resemble those of rupture of the 
Achilles tendon, which in this fracture also loses its lower point of 
insertion, though fracture of the calcis is generally more painful than 
rupture of the tendon. The broken fragment is drawn upwards by the 
tendon, and the animal is totally unable to stand on the limb, which 
collapses. All the joints are excessively flexed, particularly the tarsus. 
In moving, the limb is lifted and the metatarsus and phalanges dragged, 
the tendo Achillis appearing relaxed. Crepitation is sometimes heard, 
whilst in compound fractures splinters of bone may possibly be detected 
in the wound. 
In horses and oxen treatment is rarely successful, but in small animals, 
which offer some chance of recovery, it may be attempted. Union is 
rendered difficult by the displacement of the fractured parts consequent 
on the pull of the Achilles tendon, by their defective nutrition, and by 
the inability of large animals to stand continuously on the other hind 
leg, though Brauer says he completely cured oxen in four weeks by 
applying a plaster bandage. Detroye reports a similar case in a steer : 
the lameness completely disappeared after a time. Haase likewise 
reports union in the horse, though the case lasted from twelve to fourteen 
weeks. It would be interesting to attempt the reunion of fractured os 
calcis in the dog or other small animal by screwing the fragments 
together with silvered wood screws, or by pegging with ivory pegs. This 
particular operation does not seem to have been attempted hitherto. It 
would demand perfect technique, but appears, a priori , within the range 
of possibility. 
The prognosis, therefore, depends, firstly, on the degree to which 
the fragments are displaced (sometimes dislocation is minimised by the 
insertion of the flexor pedis perforatus) ; and, secondly, on the length 
of time during which the animal can stand on the other foot without 
laminitis setting in. Compound fractures may generally be looked on 
as incurable. 
Treatment is in general similar to that in rupture of the Achilles 
tendon. In these cases also it is important to fix the hock-joint in as 
complete extension as possible. Plaster bandages are useful for small 
animals. 
(b) Fiactuie of the astiagalus is also rare \ it follows forced rotary 
movement of the limb whilst the animal s weight is upon it, or whilst 
it is fixed to the ground. A heavy cart-horse was seen to produce this 
fracture by suddenly turning round. A case of Furlanetto’s in a cow 
was caused by falling into a ditch. 
