Gerbils vary considerably in their response to handling and may be extremely active and difficult to catch. Although they possess a long tail which might seem to represent a convenient means of restraint, this should not be grasped as the skin is readily shed if subjected to more than minimal traction. If the animal is accustomed to handling, it can be cupped in the palm of one hand. More secure restraint is achieved by first immobilising the animal by cupping in both hands, or by placing one hand over the animal. The fingers can then be positioned to surround the animal’s body, with its head protruding between thumb and forefinger. Alternatively, the skin overlying the back and neck can be gripped as described for the mouse.
Following initial restraint, the gerbil should be grasped around the shoulders and thorax, and additional restraint obtained by holding the hind limbs. An assistant should extend one of the animal’s hind limbs, and an intraperitoneal injection can then be made into the posterior quadrant of the abdomen, with the needle being directed along the line of the hind limb.
Intramuscular injections should be made into the quadriceps muscle with the animal restrained in the same manner. Subcutaneous injections can be made into the flank, or alternatively the method of restraint can be changed so that the scruff is grasped and injection made into the anterior aspect of the skin overlying the neck.
Intravenous injections can be made into the lateral tail veins, but since the skin of the tail is so fragile, some form of restraining device should be used, as illustrated for the mouse.