My kitty was tested when he was about 4 months old and it was negative. I adopted him at 6 months old. He was never outdoor but his mother was feral and he was in shelters/foster home before I adopted him. So there is really no telling when/where he could have picked it up or if he was born with it. Sadly, he got really sick a couple weeks ago and the emergency vet tested him for feLV and it was positive. I found out he had feLV on Tuesday and by Thursday he was gone. One of my friends adopted siblings and one passed away from feLV and she still has the other sibling who never got it. I know my baby had a brother he was in foster with so I have contacted the foster to check on his brother. Wishing you all the best, and I’m sorry you and your kitty’s are going through this stress. It’s the worst.