ON TRACHEOTOMY IN THE HORSE. 
505 
half an inch square, or perhaps a little wider than it is long’. 
There are no bloodvessels of any consequence to interfere vviih 
this dissection, and the haemorrhage will be slight. 
Manner of Excising the Rings, — The surgeon will now ex¬ 
change the scalpel for a sharp-pointed bistoury, and plunging it 
into the ligament at the point which is to bound the aperture 
laterally, he will carry it upward until he has cut half way through 
the ring. He will then turn his hand and carry the knife trans¬ 
versely along the middle of the ring, until he has arrived at the 
boundary of the intended aperture on the other side; another 
turn will take the knife through the lower half of this ring, the 
ligament, and the upper half of the ring below: he will then 
pu rsue the same line along the centre of that ring, and afterwards, 
taking hold of the part now almost detached, he will complete 
the excision by one more turn upward. The bistoury should be 
keen, and the hand .should glide as swiftly as the preservation of 
the form of the aperture and half the substance of the rings will 
permit. Some make a simple incision into the trachea, and then 
introduce a small tube. I shall speak of the tube presently : but 
this incision must be much longer than is necessary in the ope¬ 
ration I have described; two of the rings at least must be cut 
through, and then there will be a longer, roof-like projection, and 
greater contraction of the trachea. 
It is wonderful to observe what instantaneous and perfect relief 
this affords ; the horse that was struggling for breath, and seemed 
every moment ready to expire, is in a moment perfectly himself. 
No Tube to be inserted. —What is now to be done with the in¬ 
cision ? That depends on the purpose to be effected by the ope¬ 
ration. If the orifice is only to be kept open while some foreign 
body is extracted, or ulcer healed, or tumour removed, or inflam¬ 
mation subdued, nothing more is necessary to be done, than to 
keep the lips of the integument a little apart, and that may be 
effected by passing some strong thread through each, and some¬ 
what everting them and tying the threads to the mane. A tube * 
is not required; it is injurious ra < her than serviceable; it must, 
irritate the lining membrane of the trachea, and, occasionally, at 
least, annoy the animal and produce considerable inflammation. 
Tubes in permanent Obstruction. —If, however, there is any 
permanent obstruction, as a large tumour in the cavity of the 
nostrils, or distortion of the larynx or trachea, then a tube will be 
convenient. If it be two or three inches long, curved at the 
top, and the external orifice turning downward, with a little 
ring on each side, by which, through the means of tapes, it 
may be retained in its situation, it will answer every purpose. It 
should be taken out and cleaned daily, and the wound attempted 
VOL. V. 3 Y 
