How come you don't know how much he weighs?
I would take that dog to the vet and weigh him. Then I would ask the vet to evaluate his condition with regards to his weight. If he is over-weight, then it will take a toll on his internal organs, and his joints, ultimately diminishing his quality of life and his lifespan.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC