to Ed Plumer, adn Fili (who has half the normal PCV: Ed - there are several other possible causes of anemia in ferrets that your vet should consider. 1) Bleeding gastric ulcer. This can be a source of chronic blood loss in the ferret. Have you noticed any tarry stools from Fili recently. Not that the stools have to be tarry - small amounts of blood would not show up when you examined the feces. Has there been any diarrhea or grinding teeth (sign of abdominal pain)? 2) Ectoparasites, such as fleas. This is a commonly overlooked cause of anemia in ferrets. Fleas suck blood, it only takes a few to put a dent in a ferrets packed cell volume... 3) I have seen several cases of rapidly progressing anemia in ferrets that most likely have to do with an autoimmune response, or something that makes the body break down it's own blood cells. We don't know the reason for it, nor do we have a suitable treatment. We have tried removing the spleen in these animals, which prolongs the life of the cells, and high doses of steroidss, but the animals often don't make it in spite of treatment. This is a rare condition, though. If incomplete spaying is the cultprit, you should also see other signs of estrus, including a swollen vulva. Hope this helps... Bruce Williams, DVM Department of Veterinary Pathology [log in to unmask] Armed Forces Institute of Pathology (202) 782-2600/2602 Washington, D.C. 20306-6000 [Posted in FML issue 1043]