Under weight bulldog

Question
I recently adopted a male English Bulldog from a rescue.  He's 7 years old, smaller frame but big feet. I keep thinking he needs to grow into his feet.  I can't seem to get him to put any weight on. He weighs 51 lbs, his back bone shows and I can count his ribs.  He eats, he doesn't skip a meal.  He's been to my vet and she hasn't found any health issues associated with his weight.  He has a bowel movements every time I take him out and he has bad gas.  So I think its associated with what I'm feeding him (Solid Gold dog food).  I recently purchased Royal Canine Med. 24 for Bulldogs and I'm hoping this will help.  Any advice? This is not my first bulldog and all of them have been on the chubby side.  

Answer
First of all I can't believe a rescue would adopt him out in this condition. If he seems to feel good and eating good, the first thing I would do is worm him even if he's been wormed recently. I would especially worm him for tapeworms. It's rare you would find tapeworm segments in a fecal exam.

You might try Innova dog food or Wellness.  I use Nutri Source but you can't find it everywhere. These are natural foods, excellent quality, and not affected by the tainted dog food plague.

I would also free feed him. Keep a bowl full of food on the floor all day and pick it up around 6 p.m. If you don't see a marked improvement in 2 weeks, I would take him back to the vet for some blood work. If he's still skinny, there has to be a reason for it.

Good luck.