Alright well it pretty much says it all in the name, I had a vet 1 staghound (Which the vet didn't show up when I took it in game) and after the round I had earned quite alot of XP with it and took it off field (It had less XP then it did before I started the round) Which leads me to believe it wipes XP when you take it in game? not sure but if somebody could take a look at this i'd appreciate it very much, (when you aren't busy of course)
