We just adopted this beautiful boy! He was fixed and vaccinated. But we were told that his mother was tested twice for Feline leukemia. She came back negative. He has a great coat, good eyes, no discharge or anything, seems to have a good appetite. We plan on taking him to the vet ASAP for a check up, but should I keep him away from my other two cats for the time being? Or do you think it's safe to try and start introducing him to them?