EXPERIMENTAL TECHNIQUES (cont)
Test compounds may be administered orally or parenterally. For oral dosing, a ball-tipped gavage needle affixed to a dosing syringe is carefully passed over the tongue into the esophagus
Oral dosing in the rat
If the needle is misdirected into the trachea, the operator will encounter resistance and the animal will probably struggle. Compounds should never be dosed if the operator is unsure of the needle's placement. Forcing the needle may cause penetration of the pharynx or esophagus.