Dogs lose weight for a variety of reasons. Stress or unexpected change can cause a dog to stop eating well, illnesses such as parasites or intestinal issues can make it impossible for a dog to retain weight no matter how much she eats. Before working on weight gain, it is important to have her seen by a veterinarian for a full exam to rule out and treat any health issues that are causing the weight loss.
Choose a good quality kibble that is high in both protein and fat and has real meat as the top ingredient. Avoid foods with cheap fillers such as corn and animal byproducts. Puppy food is generally much higher in needed nutrients and is a good choice for emaciated adult dogs as well. Mix in a canned food to make the kibble more appealing to a dog with little appetite. Feed the designated amount of kibble according to the direction on the bag, according to the weight your dog should be, twice daily.
Many foods meant for humans are excellent for putting weight on dogs. Bake or boil sweet potatoes and mix in with her regular food. Cook brown rice in chicken broth and add chicken to replace a regular food meal once or twice a week. Smear peanut butter on treats for added protein. Add pieces of avocado to food occasionally for added fat.
There are many nutritional supplements for dog on the market that will add much needed nutrients and calories to her diet. Use the amounts directed by the packaging each day to every feeding to aid in weight gain. Continue using the supplements daily until she is at an acceptable weight.
Another option is to make satin balls, raw meatballs made specifically for dogs to aid in weight gain. To make a batch, mix together a pound of fatty hamburger, 1/2 cup wheat germ, 1 pack of gelatin and 4 1/2 teaspoons of molasses. Add in 3 egg yolks, 4 1/2 teaspoons vegetable oil and 3 cups of uncooked oatmeal. Form the mixture in to one inch balls and freeze them. Thaw several each day for treats.