The first thing we recommend, Lyn, is that you provide your dog with a high-quality food. In addition to canned food, you may want to make dry food available to her on a free-choice basis, at least until she reaches a healthy weight. She should also be on a parasite treatment and prevention plan to ensure that parasites are not contributing to her lack of weight gain. Parasites can sometimes be present, even when they’re not identified on routine screening tests.
You should also keep in mind that there are other potential health problems that could prevent your dog from gaining weight, including absorption and metabolic disorders. We encourage you to continue working with your veterinarian to identify the problem. If your vet is not able to identify the cause, then we recommend you turn to a specialist for additional help.