RATS DOGS 163 



mouth of the jar so that only the tail projects. Inoculation can now be 

 made at the root of the tail. If it is necessary to inoculate into one of the 

 limbs, pull the limb out of the jar with a pair of forceps. [The inoculation 

 can however be performed in the following manner which is we think simpler 

 than that just described. Let an assistant catch the rat by the tail and hold 

 the hind limbs with one hand and the fore limbs with the other at the same 

 time wrapping a small cloth loosely round the animal's head. The inoculation 

 can now be made by the operator into any part of the animal's body. If the, 

 rat bites it does not damage the cloth.] 



Anaesthesia. For all delicate operations it is better to anaesthetize the 

 animal. Rats and mice are easily killed by chloroform, but take ether 

 well. 



Put the animal under a bell jar with a small piece of absorbent wool soaked 

 in ether ; or the wool can be put straight into the jar in which the animal 

 is living. When it falls over motionless take it out of the bottle and fix 

 it on a small tray ; in the case of rats, if necessary, put on a Ranvier's rat- 

 bit as well, or use a Debrand's apparatus. Anaesthesia can be prolonged by 

 giving a little ether from time to time. 



4. Grey rats. 



Gre"y rats [Mus decumanus] struggle vigorously and may give very nasty 

 bites. They can only be caught with a pair of large strong forceps, such as 

 those described above (fig. 131). 



Pass the forceps into the bottle containing the rat and catch hold of the 

 animal quickly wherever it is possible to do so. The rat at once attacks the 

 forceps and bites them ; while the animal is thus engaged, fix a second pair 

 of forceps on to the skin of the neck, clamp the two pairs of forceps firmly 

 and lift the animal out of the bottle. 



During the inoculation, an assistant holds the rat securely with the two 

 pairs of forceps, inclining the forceps fastened to the neck towards the ver- 

 tebral column in order to pick up the tail with the same hand. With the 

 other hand he takes the other pair of forceps and pulls on them gently so as 

 to make it impossible for the animal to use his teeth. If this second pair 

 of forceps was badly fixed, the skin over the lower jaw should be held with 

 another pair. When the operation is done place the rat safely inside the 

 bottle again before releasing the forceps. 



Anaesthesia. Grey rats should always be anaesthetized before beginning 

 a difficult or dangerous inoculation. Put a pledget of wool soaked in ether 

 in the bottle, and proceed as already described in the case of white rats. 



5. Dogs. 



If the dog be a quiet animal catch hold of him firmly by the skin of the 

 neck. When dealing with a surly or snappy dog use a special pair of long 

 iron forceps (pince a collier), which, when closed, form a collar round the 

 animal's neck. Alternatively, throw a noose round the animal's neck and 

 fasten the loose end to a bar of the cage or a post ; as the dog pulls the noose 

 tightens, the animal falls over half suffocated, and the opportunity is taken 

 to slip on a muzzle and tie its feet. 



Muzzling. No operation should be performed on a dog without muzzling 

 it beforehand. The simplest method is to pass a piece of stout string into 

 the animal's mouth behind the canine teeth, make a simple knot below the 

 jaw, bring the two ends up and tie them in a double knot on the nose. Or, 

 after passing a stout round iron wire behind the canine teeth, take two turns 



