I haven't ever heard of any research that indicates what could happen if you vaccinate an FELV+ cat for FELV. Most people seem to assume that it would make no difference to the course of the FELV disease but I don't think that is based on real information.
I thought the reason vets almost always recommend against it is that injection induced sarcoma - or tumor growth at the injection site - is highest for the FELV vaccine (although still very minimal). So vaccinating for FELV when not necessary is subjecting the cat to the risk of the tumor growth at the injection site. One might want to run the risk of tumor growth if there was a beneficial affect in terms of length of life with the vaccination. _______________________________________________ Felvtalk mailing list Felvtalk@felineleukemia.org http://felineleukemia.org/mailman/listinfo/felvtalk_felineleukemia.org