RUMEN OTOMY. 
325 
movement should be made. If the operator is of slight statuie, it may 
sometimes be easier to give a smart blow on the instrument with the 
open hand. On account of the size and distension of the lumen, 
it is of no importance how far one thrusts the trochar ; no injury is 
likely to result, and therefore it may be allowed to enter almost up to 
its shield. 
When the stilette is removed the gas rushes out, sometimes under 
high pressure and mixed with particles of food, which are apt to block 
the canula, and require to be removed with the stilette or a probe. 
The canula remains in position until fermentation ceases and dangei 
of suffocation disappears. To make sure of this the canula is closed 
with a cork and the animal watched ; if tympanites fail to recur, the 
instrument can be removed. Before doing so, however, a few 7 ounces of 
creolin or other active but unirritating antiseptic may be injected; the 
stilette is then reintroduced, the skin is held in position with the fingeis 
of the left hand, and the whole instrument slowly withdrawn. 
The skin wound requires no particular treatment, though it may be 
cleansed and covered either with a pitch plaster, some tar, or collodion. 
When time serves it is best to disinfect the skin and trochar before 
operation. 
Bad results seldom follow the use of the trochar in oxen, though 
digestion may sometimes be impaired by the rumen becoming adheient 
to the abdominal wall. 
The operation is more dangerous in sheep, though it becomes neces¬ 
sary in cases of threatened suffocation. If possible, the long wool 
should first be clipped away. Where the rumen is punctured with a 
knife, a thin tube, an elderberry stem, or even a couple of strong straws 
may be used as a canula to allow of escape of gas, being intioduced 
into the rumen alongside the blade. The animal must be watched 
during the whole time these remain in position to prevent tlieii being 
displaced. 
Rumenotomy. In dealing with a rumen distended with masses of 
fermenting food containing much gas, when the tiocliai is no longei 
of value, rumenotomy, which cattle tolerate very well, can alone give 
relief. 
The animal is placed with the right side against a wall and fastened 
up short. A piece of wood held in a sloping direction in front of the 
left hind-foot, or a stake driven into the ground, will shield the operator 
from injuries by this foot. 
The hair over the left flank is now clipped, the skin cleansed, and 
a strong bistoury introduced at the point where the rumen is usually 
punctured, with its back towards the animals veitebise (Heitvig s 
method) ; the blade should be thrust in as far as the handle. With a 
