Administering Drugs to Rodents by Mouth

are introduced into the cesophagus or the stomach with the help of a rubber catheter, but during the process of introducing the catheter, specially in smaller animals such as guinea-pigs, rats, etc., the catheter may be pushed by the tongue in between the upper and lower set of teeth and may be bitten and punctured by them and the fluid comes out through the punctures. It is therefore very difficult to be sure just how much of the drug reaches the stomach. Rodents have two long central incisors in each jaw. They have no canine teeth. The other teeth are placed inside the oral cavity and there is a large space between the incisors and the other teeth ; this is why the other teeth are not visible when the mouth is opened. This is well demonstrated in the accompanying diagram (see figure 1).