Best Dog Weight Gain Supplements (2026) – Top 10 Reviewed

Whether your dog is recovering from illness, is a picky eater, or simply burns more calories than they can consume, a quality weight gain supplement can make a world of difference. These high-calorie formulas are designed to help underweight dogs put on healthy pounds without overloading their digestive system. We’ve tested and reviewed the best dog weight gain supplements available to help your pup reach and maintain a healthy body condition.

Our Top Picks at a Glance

• Best Overall: Bully Max Weight Gainer Soft Chews – Probiotic-enriched high-calorie chews for all breeds
• Best Value: PetAg Dyne High Calorie Liquid – Trusted liquid supplement at an affordable price
• Best Premium: Miracle Vet High-Calorie Weight Gainer – Nutrient-dense gel with multivitamins

Quick Comparison

Product	Key Ingredients	Form	Servings	Best For
Bully Max Weight Gainer Soft Chews	High-calorie blend, probiotics	Soft chews	75	Overall weight gain
PetAg Dyne High Calorie Liquid	Soybean oil, omega fatty acids	Liquid	Varies by weight	Budget-friendly calorie boost
Miracle Vet High-Calorie Weight Gainer	Omega fish oil, calcium, multivitamins	Gel	Varies by weight	Complete nutritional support
MVP K9 Formula Mass Weight Gainer	40% crude fat powder blend	Powder	90	Maximum calorie density
All American Canine Bulk Weight Gainer	Beef broth protein, whey, flaxseed	Powder	230	Working & active dogs
Bully Max Liquid Weight Gainer	Omega-3, whey protein	Liquid	Varies by weight	Picky eaters
Mega Cal High Calorie Supplement	High-calorie gel, vitamins, minerals	Gel	Varies by weight	Recovery & malnourished dogs
Bully Max 2-in-1 Muscle Builder Tablets	Vitamins, minerals, amino acids	Chewable tablets	60	Muscle-based weight gain

1. Bully Max Weight Gainer Soft Chews – Best Overall

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Bully Max has earned a reputation as one of the most trusted names in canine nutrition, and their Weight Gainer Soft Chews deliver serious calorie density in a convenient, tasty format.

Each bag packs approximately 1,500 calories along with 250 million CFUs of probiotics for digestive support. The formula is designed for dogs of all breeds and ages, from underweight puppies to seniors struggling to maintain body condition. Many owners report visible results within just 21 days of consistent use. The soft chew format doubles as a training treat, making it easy to integrate into your dog’s daily routine.

What We Like

• High-calorie chews with added probiotics for digestive health
• Suitable for all breeds and ages, including puppies
• Trusted brand with over 700,000 satisfied customers worldwide

What Could Be Better

• Calorie count per individual chew is lower than liquid or powder alternatives
• May not be sufficient as a sole calorie booster for very underweight large dogs

Bottom Line: Bully Max Weight Gainer Soft Chews are the most convenient way to add calories and nutrition to your dog’s diet, with the added benefit of probiotic support for healthy digestion.

2. PetAg Dyne High Calorie Liquid – Best Value

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Dyne by PetAg is one of the most established high-calorie liquid supplements on the market, trusted by breeders, working dog handlers, and veterinarians for decades.

This vanilla-flavored liquid is rich in omega fatty acids and delivers concentrated calories without limiting your dog’s stomach capacity for their regular food. It’s versatile enough to be poured directly over food or fed straight from a spoon. Dyne supports dogs in all life stages — from weaned puppies eight weeks and older to pregnant, lactating, active, underweight, and senior dogs. The high-fat, low-volume formula makes it especially useful for dogs who won’t eat enough food on their own.

What We Like

• Decades of proven results with breeders, vets, and working dog handlers
• Concentrated calories that don’t fill up the stomach, leaving room for regular food
• Sweet vanilla flavor that most dogs find highly palatable

What Could Be Better

• Soybean oil base shouldn’t be refrigerated, which some owners find inconvenient
• Some picky dogs may not enjoy the vanilla flavor on their food

Bottom Line: PetAg Dyne is a time-tested, affordable high-calorie liquid that delivers real results for underweight dogs of all life stages.

3. Miracle Vet High-Calorie Weight Gainer – Best Premium

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Miracle Vet takes the high-calorie approach a step further by combining weight gain support with a full multivitamin and mineral profile.

This gel-format supplement delivers omega fish oil, calcium, and a comprehensive blend of vitamins alongside its calorie-dense formula. It’s designed for dogs and cats, making it versatile for multi-pet households. The gel format is easy to administer — you can squeeze it directly into your dog’s mouth or mix it with food. It’s particularly valuable for malnourished rescue dogs, dogs recovering from surgery, and pregnant or nursing mothers who need extra nutritional support.

What We Like

• Combines high calories with a comprehensive multivitamin profile
• Gel format is easy to dose and administer to reluctant eaters
• Works for both dogs and cats in multi-pet households

What Could Be Better

• Premium price point compared to basic high-calorie supplements
• Gel can be messy if your dog doesn’t lick it up immediately

Bottom Line: Miracle Vet is the premium choice for pet parents who want a complete nutritional supplement that combines weight gain support with essential vitamins and minerals.

4. MVP K9 Formula Mass Weight Gainer – Best Powder Formula

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MVP K9’s Formula Mass is built for results, delivering a whopping 40% crude fat per serving to help skinny dogs and puppies pack on healthy weight fast.

This powder supplement sprinkles directly onto any dog food and binds to the kibble, ensuring maximum retention with minimal waste sinking to the bottom of the bowl. It’s recommended for any breed of dog — adult or puppy — and many owners report visible weight gain within just a few weeks of consistent use. The high fat content makes it especially effective for dogs that struggle to maintain weight despite eating normal portions.

What We Like

• 40% crude fat formula for maximum calorie density per serving
• Powder binds to kibble so nothing goes to waste
• 90-serving count provides excellent long-term value

What Could Be Better

• Very high fat content may cause digestive upset if not introduced gradually
• Not ideal for dogs with pancreatitis or fat-sensitive conditions

Bottom Line: MVP K9 Formula Mass is a no-nonsense weight gainer that delivers serious calorie density for dogs who need to put on pounds quickly and efficiently.

5. All American Canine Bulk Weight Gainer – Best for Working Dogs

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Designed with active and working dogs in mind, All American Canine’s Bulk Weight Gainer combines high-quality protein with essential nutrients for healthy mass building.

The formula features beef broth protein powder, whey protein, ground flaxseed, beef liver powder, sweet potato powder, pumpkin powder, and blueberry powder — all nutritious, whole-food-based ingredients. With 230 servings per container, it offers exceptional value for large breed owners or multi-dog households. The powder mixes easily with regular food and the natural beef flavor is highly palatable for even the pickiest eaters.

What We Like

• Whole-food-based ingredients including beef protein and superfoods
• Massive 230-serving container for long-term use
• Supports joint health, immune system, and muscle growth alongside weight gain

What Could Be Better

• Newer brand with less established track record than competitors
• Large container may not be ideal if you only need short-term supplementation

Bottom Line: All American Canine Bulk Weight Gainer is the best choice for working dogs, hunting companions, and highly active breeds that burn through calories faster than they can consume them.

6. Bully Max Liquid Weight Gainer – Best Liquid for Picky Eaters

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Bully Max’s liquid weight gainer combines omega-3 fatty acids with whey protein in a palatable formula that even the fussiest dogs will happily lap up.

This 2-in-1 supplement serves double duty as both a weight gainer and a multivitamin, providing essential nutrients alongside its calorie-dense liquid format. The omega-3s support skin and coat health while promoting healthy weight gain, so your dog won’t just get heavier — they’ll look and feel better too. It works great as a food topper for dry kibble, making it perfect for dogs who lose interest in plain food.

What We Like

• Omega-3 and whey protein combination supports overall health alongside weight gain
• Liquid format is perfect for picky eaters who refuse chews or tablets
• Made in the USA with vet-approved ingredients and zero recalls

What Could Be Better

• 16 oz bottle may not last long for larger breeds
• Liquid can make kibble soggy, which some dogs dislike

Bottom Line: Bully Max Liquid Weight Gainer is the ideal solution for picky eaters who need extra calories and nutrition in a form they’ll actually enjoy.

7. Mega Cal High Calorie Supplement – Best for Recovery

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Mega Cal provides a concentrated calorie boost specifically designed for dogs recovering from illness, surgery, or stress-related weight loss.

This high-calorie gel packs essential vitamins, minerals, and fatty acids into a dense, easy-to-administer format. It’s particularly useful for dogs who aren’t eating enough due to medical procedures, illness, or anxiety. The gel can be fed directly or mixed with food, and its concentrated formula means a small amount delivers significant calories without overwhelming the digestive system. It’s veterinarian-recommended for post-surgical recovery and malnourishment cases.

What We Like

• Concentrated gel delivers maximum calories in minimal volume
• Enriched with vitamins, minerals, and essential fatty acids
• Easy to administer to dogs with reduced appetite or difficulty eating

What Could Be Better

• Primarily designed for short-term recovery rather than long-term weight maintenance
• Can be pricey for ongoing daily use with large breed dogs

Bottom Line: Mega Cal is the go-to supplement for dogs recovering from illness or surgery who need concentrated calories and nutrition during their healing process.

8. Bully Max 2-in-1 Muscle Builder Tablets – Best for Lean Mass

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If you want your dog to gain weight in the form of lean muscle rather than just fat, Bully Max’s Muscle Builder tablets are specifically formulated for that purpose.

These chewable tablets deliver a targeted blend of vitamins, minerals, and amino acids designed to support muscle gain and growth. Just one tablet daily can help build lean muscle mass, improve energy levels, and enhance overall body condition. The formula is suitable for all breeds and ages, from growing puppies to adult dogs who need to fill out their frame with healthy muscle tissue.

What We Like

• Focused on lean muscle gain rather than just fat-based weight increase
• Simple one-tablet-per-day dosing for all breed sizes
• Vet-approved formula with a proven track record

What Could Be Better

• Lower calorie content than dedicated weight gainers — works best paired with a high-quality diet
• Results require consistent exercise alongside supplementation

Bottom Line: Bully Max Muscle Builder tablets are ideal for dogs that need to gain healthy, lean muscle mass rather than just adding body fat.

How to Choose the Best Dog Weight Gain Supplement

The right weight gain supplement depends on why your dog is underweight. If your dog is a picky eater who simply won’t consume enough food, a palatable liquid or soft chew that adds calories without filling them up is your best bet. For dogs recovering from illness or surgery, a concentrated gel supplement delivers maximum calories in a small volume that won’t overwhelm a sensitive stomach.

Consider the calorie density of each supplement. Powder and liquid formulas generally offer the highest calorie-per-serving ratio, while soft chews and tablets are more convenient but may deliver fewer calories per dose. For very underweight dogs, you may need a high-fat powder formula, whereas dogs who just need a slight boost might do fine with a chew-based supplement.

Pay attention to the ingredient quality. The best weight gain supplements use real food ingredients like beef protein, whey, flaxseed, and healthy fats rather than cheap fillers and artificial additives. Added probiotics are a significant bonus since they help ensure your dog can actually absorb and utilize the extra calories you’re providing.

Always introduce weight gain supplements gradually. Starting with half the recommended dose for the first few days allows your dog’s digestive system to adjust, reducing the risk of loose stools or stomach upset. And if your dog is underweight due to an underlying health condition, consult your vet before starting any supplement regimen.

Benefits of Dog Weight Gain Supplements

The most obvious benefit of weight gain supplements is helping your dog reach a healthy body weight. An underweight dog is at increased risk for a weakened immune system, poor coat quality, reduced energy levels, and slower recovery from illness or injury. By providing concentrated calories and nutrients, weight gain supplements help close the gap between what your dog eats and what their body needs.

Many weight gain supplements also provide essential vitamins, minerals, and fatty acids that support overall health beyond just adding pounds. Omega fatty acids promote healthy skin and a shiny coat, probiotics support digestive health, and protein-rich formulas help build lean muscle tissue rather than just body fat. This means your dog doesn’t just gain weight — they gain health.

For working dogs, sporting breeds, and highly active dogs, weight gain supplements help maintain optimal performance and stamina. These dogs often burn through calories faster than they can eat, especially during hunting season, competition periods, or intense training. A quality weight gain supplement ensures they stay fueled without the bloat and discomfort of simply eating larger meals.

Frequently Asked Questions

How do I know if my dog is underweight?

You can perform a simple body condition check at home. If you can easily see your dog’s ribs, hip bones, and spine without pressing, they’re likely underweight. A healthy dog should have a visible waist when viewed from above and a slight abdominal tuck when viewed from the side, with ribs that you can feel but not prominently see.

Can I just feed my dog more food instead of using a supplement?

Simply increasing food volume doesn’t always work. Some dogs won’t eat more than a certain amount, and overloading the digestive system with large meals can cause bloating, vomiting, or diarrhea. Weight gain supplements deliver concentrated calories in a smaller volume, making them more efficient and easier on the stomach.

How quickly will my dog gain weight on supplements?

Most owners report visible results within two to four weeks of consistent use. Healthy weight gain should be gradual — about one to two percent of body weight per week is ideal. Rapid weight gain can stress joints and the cardiovascular system, so patience and consistency are important.

Are weight gain supplements safe for puppies?

Many weight gain supplements are formulated for dogs of all ages, including puppies. However, always check the product label for age restrictions and follow puppy-specific dosing guidelines. Puppies eight weeks and older can typically use most supplements, but very young puppies should be evaluated by a veterinarian first.

Can weight gain supplements cause pancreatitis?

High-fat supplements can trigger pancreatitis in dogs that are predisposed to the condition. If your dog has a history of pancreatitis or is a breed prone to it, choose a lower-fat supplement and introduce it very gradually. Always consult your veterinarian before starting a high-fat supplement.

What’s the difference between a weight gainer and a muscle builder?

Weight gainers focus on overall calorie intake and healthy fat accumulation, while muscle builders target lean muscle mass through amino acids, protein, and specific nutrients. Some dogs benefit from both types, but the right choice depends on whether your dog needs general weight or specifically needs more muscle development.

Should I use a liquid or powder weight gainer?

Liquids work well for picky eaters since they can be poured over food or fed directly. Powders tend to offer more servings per container and mix easily with kibble. The best choice depends on your dog’s preferences and how easily they accept additions to their food.

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