Oral Gavage

A 20 gauge 38cm ball tip cannula was used to administer drug to animals. Mice were scuffed according to standard animal care operating procedures. The mice were scruffed by grasping the skin over the shoulders with the thumb and middle fingers. Next the head was gently extended back with the index finger placed on top of the head to create a straight line through the neck and esophagus. While holding the animal parallel to the work surface the gavage needle was placed in either side of the mouth, over the tongue, and advanced through the pharynx by gently pressing the gavage cannula to the roof of the mouth to elevate the head and straighten the esophagus. If there was any resistance the gavage cannula was not forced and another attempt was made after completely pulling the cannula out. After dosing the cannula was gently removed following the same angle as insertion. The mice were then returned to their cage and monitored for 5–10 minutes, assessing for any sign of labored breathing or distress. Control animals were always dosed prior to treatment animals and with different cannulas. Cannulas were cleaned with double distilled water, followed by ethanol, and then were dried with kimwipes after each dose.