
My young BC(was going to put puppy but he's a year old now)weighed more at 6 months than he does now & looked a bit chubby for my liking but he's growth upwards more & has now slimmed off. If your boy had dropped from 35 to 30 then I would be concerned. Do you have him on an adult diet or a junior/puppy I always feed less puppy than I would adult to a young dog.
I'd get the tests done just to rule out the possibility of EPI.
My GSDs were always fast eaters & my 10 year old GSD bitch still eats as if there is no tomorrow
Giving him a more food might be the way to go
Edited to add palatating the intestines & stomach isn't the nicest of experiences & even my cavaliers look uncomfortable if they have this done