Q: "i bought some frozen dead mice and rabbits, they were killed by the means of being gassed with co2 (carbon dioxide] my question is since these animals were gassed to death with co2 would this be harmful to feed my cats and ferrets?" A: This question is a gas! CO2, Carbon Dioxide, is a harmless gas as long as 1) it doesn't exist in quantities sufficient to cause enough global warming to raise temperatures high enough to melt lead, 2) you don't freeze it and mistake it for ice cream, and 3) you don't try to breathe it like oxygen. CO2 is a normal by-product of glucose metabolism, and your body eliminates a tremendous amount of it daily. When used to to kill, CO2 is pumped into a chamber of some sort, displacing normal room air, which drops oxygen levels. The death is reported to be painless the animals just drifts off to sleep--but, because CO2 levels are critical in respiration, the dying animal is seen to gasp and make exaggerated breathing motions. These are normal reactions of hypoxia, and are not necessarily an indication the animal is in discomfort. The greatest draw-back is the long period of time for the process to take place, time that some argue is long enough for the animal to become terrified. Some supply houses use liquid CO2 as a killing agent, and simply immerse the animal in the frosty fluid. For small mammals, death is virtually instantaneous. A lot of places that supply frozen mice and rats for the reptile trade use this method. In either case, as CO2 "melts", it turns into a harmless gas. Bubble it through tap water, and you have made carbonated water. It is NOT a danger to your pets, it will not change the nutritional value of your food, and it will not harm you. Provided, of course, you don't try filling your scuba tanks with the gas. Bob C [Posted in FML issue 3786]