The Best Cat Weight Gain Supplements

Life is good when your cat is happily eating his food, at the proper weight, and generally healthy. But if your cat is underweight or has recently had surgery or a health issue that caused some weight loss, you might be understandably concerned. Since most cats weigh between 8 and 10 lbs, give or take a pound or two depending on breed and size, your kitty might seem unhealthy or frail if he loses too much weight. In this case, your vet might recommend a weight gain supplement. If your cat has allergies and is not able to maintain his weight, you might want to combine one of these weight gain supplements with a hypoallergenic cat food. You can check out our list of the best hypoallergenic cat foods for more insight.

We have evaluated dozens of cat weight gain supplements of various types. Some are gel or paste supplements, some are appetite stimulants, and others are flavor enhancers to entice your cat to eat. We looked at palatability, ingredients, and how cat owners felt about them.

Best Cat Weight Gain Supplement
Under the Weather Pets Ready Cal for Cats & Dogs
Help your cat gain weight with this tasty high-calorie supplement.

Our top pick goes to Under the Weather Pets Ready Cal for Cats & Dogs. This is a high-calorie nutritional supplement that encourages weight gain when a cat is underweight. It contains vitamins, minerals, and fatty acids, and it comes in a fish malt flavor that kitties tend to love. There are two different formulations, one for cats and one for dogs, so be sure that the correct one is highlighted when you order.

The 5 Top-Rated Cat Weight Gain Supplements

Editor's PicksBrandRating
Best OverallUnder the Weather Pets Ready Cal for Cats & Dogs4.3
Best High-Calorie LiquidMiracle Vet High Calorie Weight Gainer for Dogs & Cats4.0
Best Budget BuyPet’s Choice Nutri-Vyte Nutritional Supplement4.3
Best Appetite StimulantLexelium Weight Gainer and Appetite Stimulant for Cats and Dogs4.0
Best Nutritional PowderOxbow Carnivore Care Pet Supplement4.7

*Ratings are from Amazon and may change over time.

Best Cat Weight Gain Supplement Overall: Under the Weather Pets Ready Cal for Cats & Dogs

Under the Weather Pets Ready Cal for Cats & Dogs made our top spot. This is a nutrition-heavy gel that comes in a syringe that is precisely measured so you can give your cat the right amount every time. It is made in the USA, so you can feel confident about its safety. You can use it as a partial supplement if your cat is eating but is underweight or as a full supplement if your cat isn’t eating due to illness, recent surgery, or some other reason.

To use, you’ll want to get your cat used to the flavor by putting a dab on his nose or paw, where he will lick it off. Then you can administer the correct number of clicks based on the dosage indicated for his weight.

Ingredients include malt syrup, soybean oil, cane molasses, and salmon oil. It also contains nutrients such as vitamin A, vitamin D3, potassium, riboflavin, iron, folic acid, and vitamin B12. This is a great choice if you have a cat who isn’t eating (or who isn’t eating enough) and you want him to gain weight consistently.

Under the Weather Pets Ready Cal for Cats & Dogs Key Features:

  • Fish malt flavor
  • Pre-measured for ease
  • Made in the USA
  • Can be used as a partial or full supplement
  • Contains vitamins, minerals and fatty acids

Best High-Calorie Liquid Weight Gain Supplement: Miracle Vet High Calorie Weight Gainer for Dogs & Cats

Best High-Calorie Liquid Supplement
Miracle Vet High Calorie Weight Gainer for Dogs & Cats
This weight gain supplement contains lots of healthy fats for quick results.

If you need a high-calorie liquid weight gain supplement for your cat, our top choice is Miracle Vet High Calorie Weight Gainer for Dogs & Cats. The first ingredient is fish oil, which is a healthy fat with tons of nutritional value. An added benefit is that cats tend to like the way it tastes. It also has whey protein, which is has an excellent nutrition rating. The 29 vitamins and minerals help ensure that your cat stays as healthy as possible during the period when supplementation is needed. The supplement contains no trans fats, no polypropylene, and no artificial colors.

This is a very easy supplement to administer and is great for cats who aren’t willing to eat much or who have had dental surgery, making their mouths sore and sensitive. It’s a thick liquid, so you can have your cat lick it off of a paw or mix it into a small amount of pate cat food or single-ingredient meat baby food such as turkey or chicken. Another option is to mix it with a bit of water and give it to your cat through a syringe.

Miracle Vet High Calorie Weight Gainer for Dogs & Cats Key Features:

  • Contains fish oil as the #1 ingredient
  • Uses whey protein as the protein source
  • 29 vitamins and minerals
  • Contains no trans fats or artificial colors
  • Easy to administer

Best Budget Cat Weight Gain Supplement: Pet’s Choice Nutri-Vyte Nutritional Supplement

Best Budget Cat Weight Gain Supplement
Pet's Choice Nutri-Vyte Nutritional Supplement
This nutritional gel is tasty, adds calories, and is budget-friendly.

Pet’s Choice Nutri-Vyte Nutritional Supplement made our top spot for weight gain supplements available for a budget-friendly price. Packed with vitamins, minerals, and omega fatty acids, you can be sure that your cat is getting what he needs for good health even if he isn’t eating well or is underweight. The taste is appealing to cats, too, so it should not be difficult to get him to lick it or to eat food that it’s been mixed with.

You use this product by either feeding to the cat directly or by mixing it in with his food. It has a gel consistency, so it will be neither too runny nor too difficult for a sick or weak cat to eat. If your cat is eating a normal amount of food, the dosage is 1.5 teaspoons per day; if he’s not eating much, you can give 1 tablespoon per day for every 10 lbs of body weight.

Pet’s Choice Nutri-Vyte Nutritional Supplement Key Features:

  • Contains fatty acids for healthy coat and skin
  • Can be given directly or mixed in food
  • Appealing taste
  • Contains malt syrup, corn syrup, soybean oil, and cod liver oil

Best Appetite Stimulant: Lexelium Weight Gainer and Appetite Stimulant for Cats and Dogs

Best Appetite Stimulant
Lexelium Weight Gainer and Appetite Stimulant for Cats and Dogs
An easy-to use powder that mixes with wet or dry food to improve your cat’s appetite.

Our favorite appetite stimulant is Lexelium Weight Gainer and Appetite Stimulant for Cats and Dogs. This is an all-natural powder that you can sprinkle on your cat’s regular food to entice him to eat more and gain weight. The main ingredient is beef muscle hydrolysate; it also contains yeast extract and a variety of other nutrients. There are no artificial flavors or colors.

This is a great product for your cat if he recently had surgery or an illness and his appetite is not what it was beforehand. The manufacturer recommends using it for up to 45 days, then temporarily discontinuing it for two weeks before starting it up again if it is still needed for appetite stimulation.

Lexelium Weight Gainer and Appetite Stimulant for Cats and Dogs Key Features:

  • All-natural powder
  • Mixes with wet or dry food
  • No preservatives, artificial colors, soy, or sugars
  • Stimulates the appetite
  • Can be used for up to 45 consecutive days

Best Nutritional Powder Supplement: Oxbow Carnivore Care Pet Supplement

Best Nutritional Powder Supplement
Oxbow Carnivore Care Pet Supplement
Just add water and feed to your underweight or malnourished kitty.

Oxbow Carnivore Care Pet Supplement made our top spot among powder supplements that you mix with water. This can be used for any carnivore, including cats. It’s a great option if your cat has recently had surgery or a serious illness, as it is nutritionally complete and can be used as the sole source of nutrition if needed.

This formulation is 48 percent protein and 33 percent fat, which is appropriate for an obligate carnivore’s diet. You can mix it to a paste-like consistency if your cat will eat it or you can mix it to a liquid consistency and administer via a syringe. It as a strong smell that is appealing to cats, so even a cat who is refusing food is likely to accept it.

Oxbow Carnivore Care Pet Supplement Key Features:

  • Can be used for any carnivore
  • Contains the right mix of macros for cats
  • Can be used as the sole source of nutrition
  • Good for malnourished or sick cats who are refusing their food
  • Can be mixed to different consistencies
  • Smells strong and is appealing to cats

Who Should Buy Cat Weight Gain Supplements

If your cat is sick, malnourished, or underweight, you might consider cat weight gain supplements. These should generally only be given under the supervision of your veterinarian, because some supplement types are not appropriate for cats with certain conditions. Also, any cat who is severely underweight or who is not eating needs veterinary attention.

If you know why your cat is underweight or if he has recently had surgery or an illness, then a weight gain supplement can help him regain his strength. Talk to your vet about the various types available. Some are used in place of food and others are used to make food more appealing. Still others add vitamins and minerals to your cat’s daily intake to help him gradually add weight.

Best Cat Weight Gain Supplement
Under the Weather Pets Ready Cal for Cats & Dogs
Help your cat gain weight with this tasty high-calorie supplement.

Important Features to Consider

Cat weight gain supplements come in different formulations and have various features. Here are some of the considerations you should keep in mind before choosing the right one for your cat.

  • Calories. Each weight gain supplement will provide your cat with a certain number of calories. It’s best to talk to your veterinarian about how many extra calories your kitty needs to be healthy.
  • Flavor. Most cats have their preferences, even when sick. If your cat has traditionally turned his nose up at certain flavors, check to be sure you’re not buying something that he will dislike.
  • Formulation. Does your cat need a liquid supplement, a gel, a powder that you mix with water? Maybe sprinkling taste flakes on top of his regular food will be enough to stimulate his appetite. Think about your cat’s needs and look for a product that he will be more likely to willingly ingest, if possible.
  • Vitamins and minerals. Depending on whether your cat is eating some regular food, you might need a supplement that provides just some or nearly all of the vitamins and minerals your cat needs each day.
  • Veterinary recommendation. Remember, it’s best to talk to your vet before buying anything that will replace a large portion of your cat’s regular diet. If you are just buying toppers or treats to entice your cat to eat more of his regular diet, this is less crucial, of course.

Frequently Asked Questions

What are cat weight gain supplements and how do they work?

Cat weight gain supplements can help your cat gain weight if he is underweight or malnourished. They are also good for cats who have recently had surgery or dental work and who need to regain their strength. They work in a variety of ways. Some take the place of your cat’s regular diet. Others are purely supplemental and will add calories, vitamins, minerals, and fatty acids to your cat’s intake to encourage weight gain. Talk to your vet about how to best help your cat if he needs to gain weight.

How many calories does it take for a cat to gain a pound?

A 10-lb indoor cat needs to eat about 200 calories per day to maintain their weight. Eating an extra 20 to 35 calories per day will help them gain weight. You should talk to your vet about the specific number of calories your cat should be eating each day to gain weight and then, once he achieves his goal weight, the correct number of calories to maintain that weight. At that point, you might consider one of the foods on our list of the best cat foods for indoor cats.

How much is a cat supposed to weigh?

This really depends on the type of cat you have. A small-framed cat might be perfectly healthy at 6 lbs, while a large cat (like a Maine Coon) would be healthy at a weight over 20 lbs. The average house cat weighs around 10 lbs, with males weighing a bit more and females weighing a bit less. Ask your cat how much your specific cat should weigh.

How can I make my cat gain weight fast?

The goal should not be to make your cat gain weight fast because cats have sensitive digestion systems and often can’t tolerate large increases in the amount of calories they take in. Instead, work with your vet to come up with a plan to help your cat gain weight at a reasonable rate. You might need to augment his diet with high-calorie supplements. In other cases, simply leaving food out longer or adding treats to his diet might be enough. This is something that is individual to each cat, however, so talk to a veterinary professional.

Other Cat Weight Gain Supplements We Reviewed

Best Cat Weight Gain Supplement
Under the Weather Pets Ready Cal for Cats & Dogs
Help your cat gain weight with this tasty high-calorie supplement.

We reviewed 20 other cat weight gain supplements in addition to the ones we’ve already described above. While these did not make our top 5 list, they’re still good options for you to consider for your underweight, sick, or recuperating cat.

High-Calorie Gel and Paste Supplements

EnerCal High Calorie Nutrition Supplement

EnerCal High Calorie Nutrition Supplement

This is a three-pack of high-calorie gel that is great for pets with hypoglycemia – or pets who are prone to hypoglycemia. It’s highly palatable to appeal to your cat.

Key Features:

  • Three-pack
  • Tastes great to cats
  • Contains vitamins and minerals

Cost: $19

GNC Pets Ultra Mega High Calorie Booster Gel for Cats

GNC Pets Ultra Mega High Calorie Booster Gel for Cats

This gel supplement is made with a delicious chicken flavor, so if your cat doesn’t like the fishier gels, this might be the right one to tempt him!

Key Features:

  • Good for kittens, older cats and all in between
  • Provides extra energy
  • Made in the USA

Cost: $11

Mark & Chappell Nurish-UM Paste for Cats

Mark & Chappell Nurish-UM Paste for Cats

This paste will help stimulate your cat’s appetite while providing the calories and nutrients that he needs. This is flavored with fish oil and other fish derivatives.

Key Features:

  • Best for indoor kitties
  • Fortified with vitamins
  • Fish flavor

Cost: $10

NaturVet – Cat-Cal Nutritional Gel For Cats

NaturVet – Cat-Cal Nutritional Gel For Cats

This is a gel that is appropriate for cats over 12 weeks of age. It has a highly palatable flavor and your cat can lick it directly from your finger or his paw.

Key Features:

  • Provides high-calorie energy
  • Omega fatty acids for skin and coat health
  • Manufactured in the USA

Cost: $11

PetAg High Calorie Gel

PetAg High Calorie Gel

This chicken-flavored gel can be used by cats who are pregnant, lactating, or recovering from illness. The gel is easy for your kitty to eat.

Key Features:

  • Tastes like chicken
  • Contains digestible vegetable fats
  • For cats 8 weeks and over

Cost: $8

TOMLYN Nutri-Cal Cats

TOMLYN Nutri-Cal Cats

This high-calorie supplement comes in a two-pack for double the value. It has a malt flavor that many cats find palatable and appealing.

Key Features:

  • High-calorie gel
  • Comes in a two-pack
  • Recommended by veterinarians

Cost: $15

Vetoquinol Nutri-Cal High Calorie Nutritional Oral Gel Supplement

Vetoquinol Nutri-Cal High Calorie Nutritional Oral Gel Supplement

This cat weight gain supplement works not only by boosting calories but also by stimulating your cat’s appetite. Great for aging cats who don’t want to eat.

Key Features:

  • Highly palatable
  • Contains fatty acids
  • Stimulates the appetite

Cost: $12

Other Cat Weight Gain Supplements

Ample Nutrition Digestive Enzyme for Dogs & Cats

Ample Nutrition Digestive Enzyme for Dogs & Cats

This is a supplement that helps your cat get more energy and nutrients from her regular food, allowing him to gain weight with continued use.

Key Features:

  • Use as a supplement, not as a food source
  • Doesn’t have a flavor
  • Helps boost your cat’s overall health

Cost: $26

GNC Pets Ultra Mega Premium Milk Replacer Powder Formula for Kittens

GNC Pets Ultra Mega Premium Milk Replacer Powder Formula for Kittens

If you have a kitten whose mother is not able to nurse him or he’s not gaining weight despite being nursed, this kitten formula can help him gain weight.

Key Features:

  • High-protein kitten formula
  • Provides the nutrients a kitten needs
  • Easy to digest

Cost: $14

PetAg Catsure Powder

PetAg Catsure Powder

Mix this powder with water and feed the formula to your adult cat who needs extra nutrition. It has a sweet vanilla flavor that cats find appealing.

Key Features:

  • Complete nutrition for an adult cat
  • Easy to digest
  • Tastes like vanilla

Cost: $5

Flavor Enhancers

Dr. Becker’s Appetite Boost

Dr. Becker's Appetite Boost

Made of bison and beef liver, this powder will make your cat’s regular food irresistible. Just sprinkle on and watch his eyes light up.

Key Features:

  • Good for helping your cat transition to a new food
  • Fine powder
  • Great for picky eaters

Cost: $10

Life Essentials by Cat-Man-Doo

Life Essentials by Cat-Man-Doo

You can use this single-ingredient chicken sprinkle to tempt your cat to eat his regular food or as a treat to entice him to eat something healthy and nutritious.

Key Features:

  • Healthy and organic
  • Contains only chicken
  • 2 oz bottle

Cost: $7

pawTree pawPairings Superfood Seasoning

pawTree pawPairings Superfood Seasoning

You can sprinkle this powder on top of your cat’s food or you can mix it with water and use as a gravy. It comes in different flavors for variety.

Key Features:

  • Comes in different flavors
  • Made in the USA
  • Contains meat and vegetables

Cost: $17

Purina Fancy Feast Appetizers

Purina Fancy Feast Appetizers

This very fragrant and tasty snack is meant to stimulate your cat’s appetite before you feed him his regular meal. Various flavors available.

Key Features:

  • Not a sole nutrition source
  • Convenient container that peels open
  • 1-oz portions

Cost: $11

Rachael Ray Nutrish Purrfect Broths Natural Wet Cat Food Complement

Rachael Ray Nutrish Purrfect Broths Natural Wet Cat Food Complement

These are containers of easily lickable broth that can be enjoyed before a meal as an appetizer or poured over a meal to encourage your cat to eat.

Key Features:

  • Made of real meat and veggies
  • Available in different flavors
  • Contains 24 1.4-oz portions

Cost: $25

Raw Paws Boost Flavor & Nutrition Pet Food Toppers

Raw Paws Boost Flavor & Nutrition Pet Food Toppers

This nutritious pet food topper comes in creative flavors like sweet potato, cheese, and beef liver, to appeal to the finickiest of kitty cats.

Key Features:

  • Adds flavor and nutrition
  • Made from whole foods
  • 8-oz shaker

Cost: $11

Easy-to-Eat Cat Treats

Catit Creamy, Lickable Cat Treat

Catit Creamy, Lickable Cat Treat

This is a rich, creamy cat treat that comes in various flavors. Your cat can lick it directly from the tube and enjoy a nutrition boost and extra calories.

Key Features:

  • Choose from various flavors
  • Can be used as a flavor enhancer
  • Contains 30 tubes

Cost: $15

Hartz Lickable Wet Cat Treats

Hartz Lickable Wet Cat Treats

These gravy-like cat treats are formulated for elderly cats (age 15+), who often have trouble eating and keeping their weight at the appropriate level.

Key Features:

  • Meat is blended into a puree
  • Includes vitamins important for senior cats
  • Several flavors and styles available

Cost: $12

INABA Churu Lickable Purée Natural Cat Treats

INABA Churu Lickable Purée Natural Cat Treats

These lickable cat treats are made with farm-raised chicken and other flavors. Each tube adds 6 calories to your cat’s diet, which can help with weight gain.

Key Features:

  • Available in various flavors
  • High in moisture
  • Great for mixing with medication

Cost: $40

Vitakraft Lick ‘n’ Lap Flavor Creamy Treats for Cats

Vitakraft Lick 'n' Lap Flavor Creamy Treats for Cats

This is a creamy snack that will help add calories to your cat’s diet in between meals. It contains omega fatty acids for coat and skin health.

Key Features:

  • Available in chicken and salmon flavors
  • Can be used as a food topper/flavor enhancer
  • Contains five tubes

Cost: $4

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