[Mer4ever]

I agree that getting the vet's advice and ruling out medical issues is key.

My little boy is still a bit underweight as he was being fed adult food as a puppy in his previous home and was having to fight five other (bigger) dogs to get his share.

Since he's been with us, we've been increasing his food intake gradually, and it seems to be working. This has been with our vet's guidance. The other helpful tip that the vet gave us was to put pro-biotic in his food (we get it from the vet) as it helped us transition him right away to a more appropriate diet. By using the pro-biotic, we didn't have to do the gradual transition from old to new food.

We have the dogs on a homemade diet, using a recipe that the vet gave us. Our little girl is at a perfect weight (though she too was underweight when we got her) so we have her food amount at a stable level, though we keep adjusting her brother's to ensure gradual and healthy weight gain.

Good luck! I am sure that with your love and care she will be gaining weight soon!