We've recently bought one of those arched ball launcher things to take to the field with thor. The first day we took it out he was chasing the ball down and bringing it back, but since then he won't chase after the ball. Could it be that he can't see it properly because of the frost on the grass or throwing it too far? He wasn't at all interested on today's walk. I don't mind if he doesn't like playing fetch, but just thought it was a retriever instinct. Could it be his eyesight isn't fully developed at 4 months to see the ball properly? Also... A totally different question...after his eating problems a few weeks back he is now fine and eating everything we give him but still seems hungry. Should we feed him more if it's a growth spurt or stick to the same daily amount?