FRACTURES OF THE HUMERUS. 
501 
II.—FRACTURES OF THE HUMERUS. 
Though fractures of the humerus are as a whole uncommon in animals, 
they nevertheless occur with some frequency in dogs, in which one or 
other condyle breaks away from the lower end of the humerus. Peuch 
has seen double-sided fracture of the humerus in horses. Fracture 
occasionally follows muscular exertion, as in rearing, or even in trotting. 
Horses at grass may be kicked on the arm. Drosse saw fracture of the 
“ outer and upper protuberance of the humerus ” (ridge), and removed the 
piece of bone ; recovery occurred in fourteen days. Six or seven weeks later 
the animal stumbled and broke the humerus in the direction of its length. 
Fig. 190, — Fracture of the humerus. (Hodder’s case.) 
Fractures of the diaphysis of the humerus are commonest in cattle and 
dogs, and are produced by external violence, kicks, collisions, treads, or 
accidental falls ; occasionally in horses by the animals being suddenly 
wheeled round whilst being ridden. The figure shows the humerus of a 
horse which ran away and came in collision with a wall. 
Fractures of the condyles are caused by treads, notably in dogs, though 
similar cases have been seen in horses. Sometimes the external, some¬ 
times the internal condyle is broken off in consequence of the supporting- 
leg making a violent rotary movement, or the free leg being excessively 
ad- or ab- ducted. In dogs such fractures are produced by awkwardly 
jumping or falling from a chair or table. Of twenty-six fractures of the 
humerus in dogs treated by Stockfleth, seven were through the diaphysis 
and nineteen through the condyles. 
As a rule, diagnosis of fracture of the diaphysis offers no difficulty. 
There is severe pain both when the animal stands on the limb and when 
it moves ; swelling and abnormal mobility and crepitation when the scapula 
is fixed ; the other bones of the limb are found intact. In such cases there 
can be no doubt. It is more difficult to detect fracture of the condyle. 
Sometimes the disconnected condyle is movable, and there may be crepi¬ 
tation ; diagnosis is easiest in the dog. On account of the anatomical 
