418° VETERINARY SURGICAL THERAPEUTICS. 
In some cases, if there is np displacement, the bone has kept its 
form, direction and normal length, the application of the contentive dress- 
ing may be made at once. But these cases are rare: ordinarily it is. 
necessary to modify the position of the fragments. With certain fractures, 
where the displacement has taken place in the thickness of the bone, re- 
duction is made with the animal standing; by pressures made upon one- 
end, while the other is held firm, the normal relations are reéstablished. If 
displacement is more marked, if it necessitates difficult manipulations, it 
is prudent, after the application of a temporary bandage, to cast the 
animal. The muzzled dog should be kept on a horizontal table. 
Reduction is simple if the ends are angular; it is more complicated if’ 
they are displaced in their length, overlap each other; then, there is. 
shortening of the leg, which is kept up and supported by muscular 
contraction. ; 
The manipulations of reduction include: 1, Extension; 2, counter- 
extension ; 3, coaptation. Extension is applied on the lower fragment, 
counter-extension on the upper, while at the same time both ends are put 
in coaptation. 
With small animals, most ordinarily the hands are sufficient to restore the: 
muscles to their primitive length. Let us suppose a fracture of the fore- 
arm. ‘The operator takes hold of the upper fragment with one hand, and 
of the lower with the other, and by opposite pullings replaces the bone in 
its normal length. If the dog is of large size, an assistant ‘may be neces- 
sary to apply the counter-extension. 
The reduction is more difficult in large animals, where muscular power is. 
such that it resists the combined action of several aids. The subject cast. 
on the side opposite to the fracture, has ropes secured on the upper seg- 
ments of the leg and attached to the wall or to rings fixed on post; these- 
are the mechanical agents of counter-extension. Other ropes are fixed 
round the coronet, the cannon or the lower extremity of the radius, always- 
as near the seat of the fracture as possible, avoiding to squeeze the peri- 
fractured tissues; those are held by assistants, who apply the extension 
with slow, continued, regular pulling made in the direction of the axis of 
the leg. Manual tractions of several assistants are difficult to regulate; 
they are made by jerks, and often give only imperfect results. Tackle: 
and pulleys work more regularly. Coaffation is the more delicate part of 
the operation. When thick layers of muscles cover the bone (thigh, arm) 
the ends of the bone are difficult to make out; if everything seems about: 
in place, precision is difficult, and yet on this part of the operation 
depends the complete success or the defective recovery of the fracture. 
_ For members, the mode of displacement of the lower fragment may be 
indicated by the position of the foot, the direction of the toe; these must. 
