Food to Help Your Cat or Dog Gain Weight Nutritional Guidelines for Underweight Pets

BY | December 14 | COMMENTS PUBLISHED BY
Food to Help Your Cat or Dog Gain Weight
expert or vet photo
vet verified Dr. Joseph J. Wakshlag, DVM Associate Professor of Clinical Nutrition

Cornell University College of Veterinary Medicine Ithaca, NY


We spend so much time worrying about our pets (or ourselves) being overweight, we forget that the other end of the spectrum is a major issue as well. If you're not sure if your cat or dog looks malnourished, here are a few things to look out for.

Whether your cat or dog is a new addition to the family and coming from difficult circumstances, or your long-time pal suddenly seems very skinny, it can be scary to see a pet lose too much weight. Underweight pets can be sluggish, undernourished, and are potentially at risk for more health issues if their bodies don’t get enough nutrients.

Here’s what you need to know about feeding your underweight pet and getting them the proper nutrition to regain a healthy weight.

How Can I Tell if My Pet is Underweight?

Take a look at your pet from the side. Can you see a marked indent between their ribs and hips? Look at your pet from the top. Does their back become very skinny in this area? If you can see your pet’s ribs or spine, your pet may be underweight.

Other signs of malnourishment include a lack of energy and a decline in the luster of their coat or self-grooming.

Food bowls left unfinished, of course, can also be a sure sign that your pet isn’t eating enough or has more serious health problems.

Possible Underlying Issues

Weight loss, especially sudden weight loss in a formerly healthy pet, can be a sign of underlying health problems. Parasites and worms, kidney disease, liver problems, diabetes, cancer, and heart disease, for example, can all result in weight loss.

Talk to your veterinarian if your pet continues to lose weight or won’t regain it, or shows other signs of illness like diarrhea, vomiting, frequent urination, coughing, or strange behavior.

What Kind of Food to Get

As a general rule, an 11-pound cat will need to consume between 220 to 335 Calories (kcal) a day and a 100-pound dog needs 1650 to 2250 Calories a day, depending on activity and lifestyle. If you know your pet isn’t getting enough, it’s time to try one of these tricks to boost their calorie intake.

  • Provide food that is high in calories, like puppy or kitten food, or for dogs, food that’s designed for active, athletic, or working dogs. Higher protein and fat pet foods are best.
  • Underweight pets should be eating foods that are around 30% protein and 20% fat if they’re eating dry kibble, or 7% protein and 5% fat, or higher, if you’re feeding a wet food.
  • Intersperse your pet’s diet with small amounts of high-calorie supplemental canned food or canned products made of 100% meat sources. These will have a high protein and fat content, like 100% pheasant or bison, for example. They won’t say “complete and balanced” but rather “for intermittent or supplemental use” because they’re not meant to replace regular feeding.
  • Some moist foods may be easier to digest, so your pet may retain more nutrients, and more importantly these products tend to be more palatable and tempting to a pet who isn’t eating enough.

Feeding Practices for an Underweight Pet

Try free feeding, or feeding multiple servings a day instead of one. Free feeding, or leaving out bowls of food all day, can encourage a pet to eat who is shy of eating in front of people, or who may prefer to snack on a single meal for a few hours as opposed to eating in one sitting.

Dividing your pet’s daily meal into several servings can also give your pet more opportunities to consume the calories they need.

Fun Treat Options

Some cats and dogs absolutely love cheese or boiled eggs. You can remind your pet of the joy of eating by putting a dab of cottage cheese or breaking up a slice of cheddar into their food, or adding a cooked chopped egg into the mix. Remember these are no substitute for a complete and balanced diet, but can be used as up to 10-15% of your pet’s daily intake to promote better eating habits.

You May Need Supplements

If your pet isn’t regaining a healthy weight fast enough, it may be time to supplement their diet with vitamins. These can help keep important nutrients at healthy levels while your pet regains their vitality. Talk to your vet about using a vitamin complex or multivitamin for pets.

Why Is My Pet Losing Weight?

While a controlled, and well-thought-out weight loss plan conducted in conjunction with your vet, for an overweight pet is healthy, there are some types of weight loss in pets that can be quite dangerous. Weight loss that you’re not trying to purposefully achieve should always be investigated and looked into. Losing weight in an unplanned and rapid manner should be cause for some concern. Here are some reasons why your pet might be losing weight.

  1. ParasitesWeight loss due to parasites is not as common as it used to be because pets nowadays are on heart-worm protection drugs which they receive on a monthly basis. But there’s a catch. Not all preventative drugs are equally effective to all the different kinds of parasites and worms that are in the environment.If your pet ingests contaminated water or food, he may be at risk of developing Whipworm. Weight loss is only one of the minor symptoms of having a parasite in your intestinal tract. Others symptoms include vomiting, decreased appetite, diarrhea, and soft stool.
  2. CancerMost people start freaking out every time this word comes up. Rest assured, this is only one of the possibilities and it’s not very likely that your dog has cancer in this situation. Intestinal cancer is cancer known to cause unwanted weight loss in all kinds of animals. Other symptoms include abdominal pain, vomiting, and loss of appetite.
  3. Kidney DiseasePets who have kidney disease won’t start losing weight right away. If they’re getting diagnosed with kidney disease only after you’ve discovered the rapid weight loss, chances are, your pet has been suffering from kidney disease for a while. Weight loss can also be caused by hyperthyroidism in cats.
  4. Advanced Heart DiseasePets who have this disease won’t start losing weight right away. Despite poor appetite, some dogs are known to gain weight because of bloating. The best way to recognize whether your pet’s weight loss is due to a serious condition or not is to monitor his calorie intake. If your pet lost a few pounds recently, increase his calorie intake. If he eats as he usually does and gains back what he lost, chances are that he’s just fine.
  5. Dental DiseaseOral pain can cause your pet to start eating less or stop eating all of a sudden because of the pain it causes when they chew. Dental treatments should fix the diet problem too. Monitor him closely after the treatment to make sure they’re on the right track to recovery.
  6. StressAlthough it’s not as common as the other medical conditions causing weight loss, stress is a factor that should not be overlooked. Changes in the household like a new family member or the addition of a new pet can cause stress and lead to weight loss.

Frequently Asked Questions

What can you do for an underweight dog?

If your dog is underweight, it's important to try to figure out the cause and address it as soon as possible. Some possible causes of weight loss in dogs include illness, dental problems, worms, parasites, poor quality or insufficient food, and problems with the absorption or metabolism of nutrients. If you think your dog may be underweight due to an underlying medical condition, it's important to consult with a veterinarian as soon as possible. The vet will be able to examine your dog, run any necessary tests, and provide a diagnosis and treatment plan. If your dog is underweight due to a lack of appetite, it may be helpful to try feeding your dog small, frequent meals of high-calorie, nutrient-rich food. You can also try adding a small amount of calorie-dense food such as canned pumpkin, cooked eggs, or peanut butter to your dog's meals to boost their calorie intake. It's important to note that rapid weight gain can be unhealthy for dogs, so it's important to work with your veterinarian to come up with a plan to gradually and safely help your dog gain weight.

How many times a day should you feed an underweight dog?

The frequency of meals for an underweight dog will depend on a number of factors, including the age, size, and breed of the dog, as well as any underlying medical conditions. It's important to consult with a veterinarian to determine the best feeding schedule for your dog. In general, it's recommended to feed puppies 3-4 times a day and adult dogs 1-2 times a day. However, if your dog is underweight and needs to gain weight, it may be beneficial to feed them more frequently, such as every 6-8 hours, in order to increase their calorie intake. It's also important to consider the type and amount of food you are feeding your dog. High-calorie, nutrient-rich foods can help your dog gain weight, and your veterinarian can help you determine the appropriate amount to feed your dog based on its size and needs. Again, it's important to work with your veterinarian to develop a safe and effective feeding plan for your underweight dog. They can help you determine the right balance of frequency and portion size to help your dog gain weight in a healthy way.

What can I add to my dog's food to help her gain weight?

There are a few options you can try adding to your dog's food to help them gain weight. Canned pumpkin (not pumpkin pie filling) is a low-calorie food that is high in fiber and can help your dog feel full. You can add a small amount (a spoonful or two) to your dog's food to boost its calorie intake. Eggs are a good source of protein and can be a good way to add calories to your dog's diet. You can scramble or hard boil an egg and mix it into your dog's food. Peanut butter is a good source of protein and healthy fats, and most dogs love the taste. You can add a small amount (a teaspoon or two) to your dog's food to boost its calorie intake. Some types of baby food, such as those made with meat, can be a good source of calories for dogs. Just be sure to read the label and avoid any that contain onions or garlic, which can be toxic to dogs. Cheese is high in fat and can be a good way to add calories to your dog's diet. Just be sure to choose a variety that is safe for dogs and avoid giving them too much, as cheese can be high in sodium. It's important to note that you should only add these types of foods to your dog's diet in small amounts and as part of a balanced diet. It's also a good idea to consult with a veterinarian before making any changes to your dog's diet.

How do I calculate my dog's nutritional needs?

Calculating your dog's nutritional needs involves considering several factors, including their age, size, breed, activity level, and any underlying medical conditions. It's important to work with a veterinarian to determine the appropriate balance of nutrients for your dog. To calculate your dog's daily caloric needs, you can use the following formulas. For adult dogs who are not very active or are overweight: (Body weight in kilograms) x 30 = Daily calorie needs (kcal/day). For adult dogs who are moderately active: (Body weight in kilograms) x 35 = Daily calorie needs (kcal/day). For adult dogs who are very active: (Body weight in kilograms) x 40 = Daily calorie needs (kcal/day). For puppies: (Body weight in kilograms) x 40-50 = Daily calorie needs (kcal/day). These are just general guidelines, and your dog's specific caloric needs may vary based on their individual characteristics and circumstances. It's important to work with a veterinarian to determine the appropriate calorie intake for your dog. In addition to calculating your dog's caloric needs, it's also important to consider the balance of nutrients in their diet. Dogs need a balanced diet that includes proteins, fats, carbohydrates, vitamins, and minerals. It's important to choose a high-quality commercial dog food or home-prepared diet that meets your dog's nutritional needs. Your veterinarian can help you determine the appropriate balance of nutrients for your dog.

What is the best thing to feed a malnourished dog?

If your dog is malnourished, it's important to work with a veterinarian to determine the underlying cause of the malnutrition and develop a plan to address it. The specific treatment plan will depend on the cause of the malnutrition and the overall health of your dog. In general, the best thing to feed a malnourished dog is a high-quality, nutrient-dense diet that meets its nutritional needs. This may include commercial dog food that is formulated for dogs with special nutritional needs or a home-prepared diet under the guidance of a veterinarian or a veterinary nutritionist. It's important to gradually introduce any new food to your dog's diet to avoid stomach upset. You may need to feed your dog smaller, more frequent meals to help them gradually regain their strength and improve their nutritional status. It's also important to follow your veterinarian's recommendations for feeding and monitoring your dog's progress. They will be able to determine the appropriate amount and type of food for your dog based on their specific needs and circumstances.
More on Pet Nutrition

Ideal Dog Weight Chart
Nutrition to Treat Liver Disease in Cats and Dogs
Find the Best Pet Food for Your Dog or Cat

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis, or treatment by, your veterinarian. It has however been reviewed for accuracy by Dr. Joe, a board certified veterinary nutritionist and graduate of Cornell University's program for Veterinary Medicine.

Was this article helpful?
High Protein Heart Disease Kidney Disease Underweight

You May Also Like