A facemask for gaseous anesthesia in laboratory rodents and chicks that allows easy access to the eyes for ophthalmic procedures.

PURPOSE: The purpose of this study is to report a method for making a cheap and effective anesthesia facemask for laboratory rodents and chicks that allows access to the eyes for ophthalmic procedures such as electroretinography (ERG) and optical coherence tomography (OCT).

METHODS: The facemask is fabricated from a bulb syringe and a medicine dropper (Luvs(®) , Jamaica, NY) both intended for use in infants. The tip of the bulb syringe is removed to make a plastic cone (1.5 cm in length) to fit over the animal's nose. The bulb is removed from the medicine dropper and a small hole on the side of bulb near the closed end made into which the narrow end of the plastic cone is fitted and the joint glued with a hot glue gun. The facemask is then attached over the anesthetic tubing.

RESULTS: Following induction of anesthesia, the facemask and a nonrebreathing circuit (Baines system) are suitable to maintain anesthesia in laboratory rodents and chicks while allowing ready access to the eyes for ERG and OCT. The mask fits snuggly, reducing leakage of anesthetic gasses and it has a minimum of deadspace.

CONCLUSIONS: The materials required for making the facemask are cheap and readily available and it is easy to fabricate. We found it excellent for use with mice and chicks, and it allows easy access to the eyes for techniques such as ERG and OCT.