Modifying a displacement pump for oral gavage dosing of solution and suspension preparations to adult and neonatal mice

To assess a drug's toxic or carcinogenic effects on neonatal and adult mice and rats, researchers often carry out oral gavage studies. Whether dosed singly or in various combinations, provided as soluble solutions or as colloidal suspensions, the drug must be delivered in accurate and precise doses. For studies that require newborn mice to receive multiple daily doses, delicately handling neonates to increase their chances of surviving is just as critical as the ability to accurately dose small volumes. To help ensure accurate and precise delivery of drug doses ranging from 5 for neonatal mice to 400 mu l for adults, the authors adapted an automated pipetting system. By slightly modifying standard gavage needles, the authors delivered, on average, 98-99% of targeted dose volumes to neonatal mice.