CAT LOVEPURR

So, I ended up getting a cat in my new pet friendly apartment…at any rate–he had giardia a few months ago and recently had a UTI. When I got him, he also had a URI (upper respiratory infection). The humane society says it checks for Feline Leukemia before cats are “okayed” to be adopted…but I’m worried about his frequent diarrhea (he still has bouts of it) and his tendency to be extremely sensitive to his environment. He has put on weight, but still hasn’t gained a lot. He is pretty vivacious for the most part, even when he has bouts of diarrhea…Could he have Feline Leukemia? Even if they check for it? I’m really worried right now.

Thanks for your help.