DEPARTMENT OF SURGERY. 
49 
Haemorrhage may again start in a veterinary wound the first, 
second or third day (or even later) after an operation from 
bumping a wound against the stall, lying upon a wound, or by 
moving when a wound is near a joint, but the more serious form 
is the one caused by the sloughing of a ligated stump of an 
artery or large vein. A vessel that is friable from disease may 
bleed when the stump sloughs away too soon, but under ordinary 
circumstances a vessel that is properly ligated, even though it 
be a very large one, should not cause any trouble. If the human 
surgeon can successfully ligate the renal artery and vein in 
ablation of a diseased kidney, the veterinary surgeon should 
certainly not fear serious results from the comparatively minor 
vessels that are met in the various operations and accidents. 
The key to successful ligation is to have the ligating 
thread neither too large nor too small. The thread should be 
small enough to wound the internal coat of the artery so that 
the wounded endothelium may form a nucleus for the coagulum. 
It is also said that if the internal tunic is cut through its con¬ 
tractility will partially occlude the lumen of the vessel. If the 
thread is too large these results are not obtained, while if too 
small the stump may slough away too soon, and in either case 
secondary bleeding may be expected. The metacarpal and the 
metatarsal arteries can be safely ligated even without com¬ 
plying with these precautions, but the carotid and thyroid 
arteries and the thyroid veins require perfect ligation. 
Wound Sterilization—Disinfection of Wounds .—After a 
wound is free from blood the next step is to attend to its dis¬ 
infection. “ Mechanical disinfection,” previously referred to, 
constitutes one of the most perfect methods of ridding a wound 
of infective matter, but since such a feat can never be accom¬ 
plished without causing haemorrhage it must be done before 
one has gone to all the trouble of arresting the haemorrhage. 
Surgical or mechanical disinfection having been attended to in 
the second step before haemostasis, there remains to be dis¬ 
cussed only “ chemical disinfection,” i. e ., the disinfection of 
wounds with antiseptic drugs. 4 
A surgical wound made in a non-purulent area should require 
no disinfection whatever, if the surgeon’s methods have been 
correct and no accident has occurred during the operation to 
carry infection into it. But accidental wounds and purulent 
surgical ones require perfect sterilization. It matters not how 
soon a wound is treated after the accident, it must be put 
through a systematic and intelligent cleansing process, even 
