[PaddyD]

28 at the withers? Big dog. Weight is highly variable depending on build and amount of exercise. Especially build. Big boned? Long and lanky? Broad chested? etc
If you think 80 is good you probably know best. Ask a vet.

 

[PaddyD]

Why would get mad if someone calls him a wolf?lol. I would take it as a compliment!=D

Back on topic, I agree with what everyone else is saying.

He is young and as stated above he will fill out naturally, assuming he is healthy and well-fed. If he is a natural fetcher, there are a number of throw toys you can use to exercise him, including a frisbee. If possible, walks in the woods are great exercise if he is free to chase squirrels, etc.