Thank you so much Spencer - I was hoping that you would repond as you are so very knowledgable in so many areas of cat care. I guess I should be sure whether Wil's leukemia is more like a human leukemia (not contagious) or if it is comparable to Aids (very contagious). Is that pretty much the difference between the cat leukemias? Our vet hasn't said to isolate Wil, or to use different dishes with him. He did say that if the leukemia moved from the blood cells to the bone marrow, then there may be a chance of the other cats contracting it. Would that be connected to the Aids version or the other leukemia? Thank you again for your concern.