Malinois Puppy Too Thin? Questions

Our Belgian Malinois, Moose, has always been thin since the day we brought him home. He is 4 and a half months old now. And he has always been a picky eater, just doesn't want to eat much sometimes, unless I add a little something extra to his food, like an egg or chicken broth. We brought him home at 11 weeks old, he had already had 2 sets of shots and been dewormed twice along with the rest of his littermates. He seemed on the thin side to me, so I asked about it when we got his last round of shots. The vet set he could use a little more weight, but he is never going to be "fat". I have seen some very skinny ones, and some over weight ones. The thing that worried me is Moose's hip bones slightly show. His spine doesn't show at all and feels healthy, and his ribs do not show at all unless running or rolling around weird, and not to mention the puppy fat, oh my goodness. His skin is so loose and flabby with puppy fat it's hilarious. He looks very healthy from the side, but still his hip bones slightly show. Any other malinois owners out there that have a thin malinois? He plays quite a bit and is in obedience training, but we are not doing protection work. Any advice how to fatten him up just a bit? The leaner the better with these dogs, but he just seems a little too thin. It is not from bad breeding. His great grandfather from Blackneck's Kennel in Sweden was World Champion in IPO3 twice. Any advice and pictures welcome! This is our first maligator! (We will be consulting our vet again this month, and having him dewormed one more time when we bring him in for his neutering apt.) Please only opinions from people that know the breed well. This is a very active, agile breed that is not a flabby couch potato.

Thank you. We will be taking a stool sample and having him dewormed as needed this month.

He looks okay to me. They should be lean and fit. Talk to your vet with any concerns.

Looks great for a Mali