DEPARTMENT OF SURGERY. 
765 
matter how warm it may be. As regards the age, the younger 
the animal the better for it, the easier for the surgeon, and the 
less danger. The best age at which the heifer should be spayed 
is six months. As to spaying a pregnant animal, I have seen 
it demonstrated that it was safe to spay one with a calf not 
more than four months gone. Of course, it causes abortion, 
which generally takes place in from 36 to 60 hours, although it 
may be longer. It matters not whether the animal is in heat or 
not. As to the milking qualities of the spayed cow, it depends 
to a great extent on the time she is spayed, according to the 
latest experiments. If the animal is wanted for milking pur¬ 
poses the correct time to perform the operation is when she is in 
her piime, which is from three to six weeks after giving birth 
to the young. In this case they generally remain good milkers 
on an average of from three to five years. 
Modus Operctndi .—The first item under this head is the 
fasting or starving of the animal. They should be fasted for 
from 36 to 48 hours, or even longer would be better, but all 
farmers don’t look at it that way. The next item is the secur¬ 
ing of the animal, which is done many different ways, but will 
only relate the most important. The one considered the best is 
the stocks, which should be provided with a door at the front 
end similar to a dehorning door. This door to be used for the 
purpose of confining the head of the animal, and at the same 
time it should be arranged so that it could be opened to allow 
the animal to walk out the front end when the operation is 
completed. There should be another door on the left side, 
which, after the animal’s head has been confined, can be let 
down so as to expose the left flank where the operation is per¬ 
formed. Some veterinarians use the block and tackle and 
perform the operation through the linea alba; again, some 
throw them, but in either of these the men that do the rough 
end of the job are generally worn out before very many opera¬ 
tions are performed, whereas when using the stocks it is no 
harder on those men than is the ordinary work of the farm 
hand. One of the most important items of this operation is 
cleanliness or sterilization. You should have an assistant to 
clip the hair ; wash the part with soap and water and then bathe 
it with a solution of some good antiseptic. Then for the 
knife, which should be kept in some good antiseptic solution 
along with the other instruments. Make a puncture into the 
abdominal cavity. This should be about half way between the 
last rib and the anterior angle of the ilium and about three 
