http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/56600.htm
I will give my understanding of the article (and it may be imperfect):
FelvA is feline leukemia. When some cats with certain types of DNA get FelvA, they also develop FelvB or Felv C. Cats with Felv A and Felvb are more likely to have lymphosarcomas (50%). Cats with FelvA and FelvC are more likely to have anemias (1%).
"Within the infected cat, FeLV-A is sometimes altered to produce FeLV-B and FeLV-C viruses. FeLV-B is found in ~50% of naturally infected cats, along with FeLV-A. The FeLV-A and FeLV-B together are more frequently associated with neoplastic diseases than is FeLV-A alone. FeLV-C viruses are isolated from only 1% of naturally infected cats, along with FeLV-A and sometimes both FeLV-A and FeLV-B. The presence of FeLV-C in an infected cat is strongly associated with the development of erythroid hypoplasia and consequent severe anemia."
I am sorry he was rude. However, perhaps there is some useful information that came from all of this.
