She's been vet checked, no worms, she's active, eats well, but she is very skinny. She gets two cups of dry food and a can of wet food with it twice a day. I've tried different foods with her but nothing has worked. Eukanuba, canidae, etc. I've given her ground beef with rice three times a week along with her regular dog food but she hasn't gained a pound. My 6 yr old daughter even sneaks her treats throughout the day. I do know that her previous owners abused her and bred her before she was a year old. The vet says she is fine at 52lbs but I can see her ribs so I'm not sure.

52lbs seems reasonable for a female pit. Just because her ribs show does not mean she is under weight, some breeds, it's just how their body structure is, some lines of pits are included, boxers, etc...

As long as she has no parasites, and you are feeding her a quality brand of dog food, and there are no other major health issues, 52 lbs, seems like an ideal weight for a young female.

Has she been spayed?

What does your vet think of your dogs weight? If they also believe that she is underweight, I would browse some of the performance dog foods. A co-worker of mine has a dog who would actually lose weight on regular food, and she is now feeding him a diet meant for sled dogs. It works well..

I agree with above response. That weight seems ideal to me too. Like she said seeing ribs is not always an issue and Pit Bulls are one of those breeds that tend to show them. If she were to gain too much more and become non ribby she would likely suffer ill effects from being over weight.

What does your vet think of your dogs weight? If they also believe that she is underweight, I would browse some of the performance dog foods. A co-worker of mine has a dog who would actually lose weight on regular food, and she is now feeding him a diet meant for sled dogs. It works well..

Her vet says the dog's weight is fine.