An evaluation of fresh gas flow rates for spontaneously breathing cats and small dogs on the Humphrey ADE semi-closed breathing system.

Objective: To evaluate the fresh gas flow (FGF) rate requirements for the Humphrey ADE semi-closed breathing system in the Mapleson A mode; to determine the FGF at which rebreathing occurs, and compare the efficiency of this system to the Bain (Mapleson D) system in spontaneously breathing cats and small dogs.

Study Design: Prospective clinical study.

Animals: Twenty-five healthy (ASA score I or II) client-owned cats and dogs (mean ± SD age 4.