PUNCTURE OF THE RUMEN. 
323 
sometimes used. In sheep the vesical catheter used for hoises foims a 
sufficiently effective probang. As the patient cannot be cast, passage 
of the probang in an excited animal suffering from severe dyspnoea is 
often no easy matter, hut cattle are usually 
better subjects than sheep. 
To ensure the instrument taking the right 
direction, a piece of wood provided with an 
opening (mouth gag) is first inserted in the 
mouth, and through this the tube is passed. 
The animal’s head is then extended and the 
rounded end of the probang pushed along 
the palate into the pharynx, whence it glides 
along the superior pharyngeal wall, and enters 
the oesophagus. Care is required to prevent 
it passing into the larynx and trachea, an 
accident which is announced by violent cough¬ 
ing and dyspnoea; in such case the tube 
must immediately be withdrawn. Should it 
have safely gained the oesophagus, it passes 
easily downwards without any untoward 
symptom, and can be felt on the left side of 
the neck. As soon as the end reaches the 
stomach the stilette is removed, and the accu¬ 
mulated gases allowed to escape through the 
hollow tube. But this does not always follow ; 
sometimes the tube becomes stopped up and 
the probe must again be introduced ; often the 
gases are not free on the surface of the con¬ 
tents of the rumen, but are mixed up with 
masses of fermenting food, and this explains 
why even the probang has not always the 
desired effect. 
* Puncture of the rumen forms anothei means 
of treatment, the rumen being pierced in the 
left flank with the trochar to allow exit of gas. 
The operation is very simple, and is often 
carried out by laymen when danger of suffo¬ 
cation threatens. In the case of cows and 
sheep even a pocket knife can be used, should 
a trochar not be at hand. . 
At the present time round troehars without side openings are almost 
exclusively used ; the largest, having a diameter of 2 to 4 lines, is used 
for oxen, and a somewhat smaller one, 1 to 2 lines, for sheep. 
Y Z 
Fig. 147.—Trocliar and canula 
for puncture of the rumen. 
