We dont routinely test, so as far as I know we haven't come across it. It woudl be tricky if we did though, as all the foster homes have exisiting cats, so unless they lived in my cat room long term (Which then means other cats can't be helped), I dont think we woud be able to accomodate them sadly. My local RSPCA branch PTS FIV+, so I should imagine they woudl do the same with FeLV, my local CP have homed a couple of FIV+ and let another elderly one with other health issues live his life out there, so hopefully would do the same with FeLV. It would be hard to rehome due to the lifespan, although I have a friend in the US who purely does that, she has 11 I think at the moment