Um, I've drastically oversimplified some of the stuff our vet told us. In particular, our vet does agree with you in that there is very little concrete information vis-a-vis the relationship between what Toby died of and FeLV, other than that Toby's syndrome was *very* similar to FeLV, and that Toby did test positive for FeLV. He did tell us that the test didn't necessarily mean anything whatsoever, and that there did not appear to be any concrete evidence that the ferret syndrome (whatever Toby died of) is necessarily a FeLV-type retrovirus other than the similarity of symptoms. He seemed somewhat reluctant to do FeLV tests in our other ferrets, but my wife and sister-in-law were sufficiently concerned that doing FeLV tests on the other ferrets would have at least *some* reassurance value. I didn't intend for my posting to cause everyone to go out and get FeLV tests for their ferrets, and if I didn't make the above clear in my posting, I apologize. I definately appear to have been incorrect in stating conclusively that it *was* a retrovirus. Regarding "rarity" - I really meant w.r.t. "absolute chance of catching it". Not relative to other diseases. And was really supposed to be relative to ferrets only. My posting shouldn't have been taken as any argument against having cats vaccinated against FeLV - they should! (We found out to our surprise that my parents hadn't vacinated their cats against FeLV. After this reminder, they're getting it done as soon as they can) Thank you for the clarifications. I have some questions for you: - Do you have any information whatsover about how long it *might* take for a neoplasm to develop far enough for an outcome similar to Toby's? (his spleen was larger than his liver when it ruptured) Even if purely conjectural, or for other animals, it might help our curiousity as to how long Toby might have had this problem. (We wonder whether we mention this to the breeder and/or pet store where we got Toby.) - Purely out of curiousity - have you noticed, or seen mention of in the literature, any seeming correlation between "exotic-colour" ferrets and physiological anomalies? Eg: Toby was a silver-mitt and he had two complete sets of anal-sac glands. Or, in cats with confirmed FeLV that have been presumed to have caught it in their mother's womb, any indication of physiological anomalies? - Do you recommend rabies vaccinations for ferrets that are house-bound and don't meet other animals? [Posted in FML 0022]