How to make a dog gain weight?

Dont take his food away if he dosent eat it right away. Some dogs like to eat through out the day. Give him 3-4 smaller meals a day. Also add white rice, vegitables, and grilled chicken to a meal a day.

That all depends How old is your dog? Is it neutered? What size is it? Med, large or small Our son has an older dog that was really under weight and the bet told them to feed him puppy kibbles Wendy

Ok going to suggest a few things for you. I saw you say you have a shih-tzu and I had one for 10 years. He too was a picky eater. He liked only very small kibble, I actually had to end up getting cat food for him. So much of the dry dog food was too big for him to eat. I think it was because he had such a small mouth. He liked some wet dog foods but very few. He always stole the cat food from the cats and I got tired of fighting him on it. He thrived on the cat food unlike how he did on the dog food. You can try mixing brewers yeast and garlic in with his food. This will help him gain weight and it helps get rid of fleas. I hope this helps.

perhaps u can feed him kibs with sweet potatoe in it? This helps to put some fats in the dog.

That sounds very unusual to me. Seldom will you see a dog that does not like to eat. I am curious what an animal doctor might have to say about it. It sounds like the dog may have some sort of medical problem..