Zorro,
I can't say for sure that your pup wasn't losing weight due to some food issue, but when you mentioned the coat blow I just felt I could share that it might have been a factor in weight loss. Our guys always grew very dense winter coats when we travelled a lot in northern climates and they were out more in winter. The coat blows were intense, and 5 of seven always lost weight when they blew coat. These same sibes blew coat twice a year, once in spring/early summer and those were the ones who lost weight, the coat blow in fall was always minimal. My other two sibes tend to shed once a year, but it continued from summer through until early fall. Their weight loss was a little bit less noticeable, but I have seen it in all our guys.
Also, as far as dog foods, I'm sure you already know this but you can take the same two dogs feed them the same Orijen formula(or any other dog food) and have one not do well, while the other thrives, that applies for any dog food. Presently we feed Honest Kitchen, cook on occasion and feed Acana, I am looking closely at Blue Buffalo too. I really like variety for the dogs, and they love it too. Although the two remaining seniors are almost Hoover vacuums and have never been picky. lol Fortunately they are healthy yet and have good digestive systems.
As far as your boy, he is BIG, I would say he is on the high end of the breed standard. If not going to be bigger than the breed standard, especially at 7 months and 61 pounds. I never did any showing so it's not something I payed tons of attention too, other than to focus on breed temperament, and stucture, in order for them to be able to do what they were bred to do. Temperament was our primary deciding factor because we rescued all our dogs. General rule, the larger the breed the slower they mature physically. I feel by age 2 a sibe is fully matured. I think the top of the weight range on a male sibe may be 60 pounds and for females 50 pounds, hence my comment about him being a big boy. Admitedly I am going off of memory here, I can look that info up tomorrow, but we are busy getting ready for first birthday party for our grandson
I admit his age and weight make me wonder a bit. He is most handsome, no doubt about that. Is he definitely a purebred or could there be some malamute somewhere in his pedigree? I know he definitely has some sibe in there with the blue eye, and the mal standard says blue eyes are a fault so I was just curious what you know of his ancestors?? Matters not to me at all, lol, because I am just a sucker for sibes and mals. If he gets along well with other dogs he can come live at my house anytime.