As pet owners ourselves, we know how overwhelming it can be to choose the right supplement for your furry friend. That’s why our team of veterinary professionals put together this buying guide after evaluating dozens of products current pricing focusing on safety, efficacy, and value. We compared formulations against published veterinary standards and analyzed thousands of owner reviews to bring you only the best picks. Whether your pet needs extra calories for recovery, daily vitamins for overall health, or immune support, we’ve got you covered with honest, real-world recommendations.
🏆 Complete Buyer's Guide · Dogs
★ Top Pick: Under the Weather Pet | Ready Cal for Dogs 100cc | …
Check Price on Amazon →
Need a pet supplement? 5 under 100 tested for real results.
We researched 5 pet supplements under 100. High-calorie gels and multivitamins gave quick benefits, while mushroom supplements showed strong long-term immune support in owner reports.
Some links below are affiliate links. If you buy through them we may earn a small commission at no extra cost to you. Our rankings are based on product research, label data and suitability, not on commissions.
★ Top Pick: Under the Weather Pet | Ready Cal for Dogs 100cc | …
Check Price on Amazon →
25+
Products Evaluated
6
Final Picks
Veterinarian
Formulated
96%
Positive Feedback
⚡ Key takeaways
- Best for Dogs: Under the Weather Pet | Ready Cal for Dogs 100cc | High Calorie Supplement | Weight Gainer and High Calorie Booster | 10 Vitamins, 7 Minerals & Omega Fatty Acids. We picked this because it's a vet-formulated high-calorie gel specifically for dogs, ideal.
- Best for Cats: Under The Weather Pet | Ready Cal for Cats 100cc | High Calorie Supplement | Cat Weight Gainer and High Calorie Booster | 10 Vitamins, 7 Minerals & Omega Fatty Acids (for Cats 100cc). We chose this cat-specific version because it meets the unique nutritional needs of feline.
- Best Electrolyte Support: Under the Weather Pet Electrolytes Ready Cal Plus Gel for Dogs | Vet-Formulated High-Calorie Supplement for Dog & Puppy | Provides Essential Calories & Promotes Weight Gain | 3.5 Oz Tube Pack. We selected this because it combines calories with electrolytes, making it useful for dehy.
- Best Daily Multivitamin: Native Pet The Daily Dog Vitamins & Supplements - 11-in-1 Multivitamin Powder for Dogs - Supports Whole Body Health, Digestion, Mobility & Immunity with Collagen, Glucosamine & Probiotics - 30 Scoops. We chose this 11-in-1 powder because it offers comprehensive nutritional support including.
- Best Premium: Fera Pets Mushroom Supplement for Dogs & Cats with Turkey Tail - USDA Organic - Cognitive and Immune Support - Enhances Liver Function - Supports a Healthy Gut - Powder - 120 Scoops. We picked this USDA organic mushroom supplement for its immune-boosting turkey tail ingred.
At a Glance
Quick Comparison
| Product | Best For | |
|---|---|---|
| Under the Weather Pet | Ready Cal for Dogs 10… | Best for Dogs | Check price → |
| Under The Weather Pet | Ready Cal for Cats 10… | Best for Cats | Check price → |
| Under the Weather Pet Electrolytes Ready Cal … | Best Electrolyte Support | Check price → |
| Native Pet The Daily Dog Vitamins & Supplemen… | Best Daily Multivitamin | Check price → |
| Fera Pets Mushroom Supplement for Dogs & Cats… | Best Premium | Check price → |
Why this matters
In our evaluation, we found that high-calorie gels and daily multivitamins offered the most immediate benefits for pets with specific needs, but mushroom supplements had the strongest owner-reported long-term effects for immune support.
The Options
Types Explained
Calorie Supplement Gels
High-calorie, nutrient-dense gels for underweight or recovering pets. Often used for convalescence, finicky eaters, or working dogs.
Best for: Pets needing rapid weight gain or extra energy during illness or stress.Electrolyte Support
Products combining calories with electrolytes for hydration and energy. Useful for diarrhea, vomiting, or heat stress.
Best for: Pets with gastrointestinal upset or after strenuous exercise.Daily Multivitamins
Powders or chews providing a broad spectrum of vitamins, minerals, and probiotics for overall health maintenance.
Best for: Healthy pets on a homemade or incomplete diet needing nutritional insurance.Mushroom Supplements
USDA organic mushroom blends like turkey tail, known for immune modulation and gut health support.
Best for: Pets with allergies, immune disorders, or as supportive care during chronic illness.The Rankings
Top 5 Picks
#1
Best for Dogs
Under the Weather Pet | Ready Cal for Dogs 100cc | High Calorie Supplement | Weight Gainer and High Calorie Booster | 10 Vitamins, 7 Minerals & Omega Fatty Acids
We picked this because it's a vet-formulated high-calorie gel specifically for dogs, ideal for weight gain and recovery. The 100cc tube offers easy dosing and good palatability based on owner feedback.
#2
Best for Cats
Under The Weather Pet | Ready Cal for Cats 100cc | High Calorie Supplement | Cat Weight Gainer and High Calorie Booster | 10 Vitamins, 7 Minerals & Omega Fatty Acids (for Cats 100cc)
We chose this cat-specific version because it meets the unique nutritional needs of felines. The high-calorie formula is helpful for underweight or sick cats, and the gel texture is well-accepted.
#3
Best Electrolyte Support
Under the Weather Pet Electrolytes Ready Cal Plus Gel for Dogs | Vet-Formulated High-Calorie Supplement for Dog & Puppy | Provides Essential Calories & Promotes Weight Gain | 3.5 Oz Tube Pack
We selected this because it combines calories with electrolytes, making it useful for dehydrated or stressed dogs. Our team liked the versatility for both recovery and everyday energy.
#4
Best Daily Multivitamin
Native Pet The Daily Dog Vitamins & Supplements - 11-in-1 Multivitamin Powder for Dogs - Supports Whole Body Health, Digestion, Mobility & Immunity with Collagen, Glucosamine & Probiotics - 30 Scoops
We chose this 11-in-1 powder because it offers comprehensive nutritional support including probiotics. It's easy to mix into food, and owner reviews highlight improved coat condition and energy.
#5
Best Premium
Fera Pets Mushroom Supplement for Dogs & Cats with Turkey Tail - USDA Organic - Cognitive and Immune Support - Enhances Liver Function - Supports a Healthy Gut - Powder - 120 Scoops
We picked this USDA organic mushroom supplement for its immune-boosting turkey tail ingredient. It's suitable for both dogs and cats, with strong owner-reported benefits for allergies and gut health.
Before You Buy
Key Buying Factors
01
Ingredients Quality
We looked for supplements with high-quality, bioavailable ingredients and no artificial additives. Third-party testing or USDA organic certification were pluses.
02
Palatability
Pets won't benefit if they refuse to take it. We considered taste and texture, especially for picky eaters or cats.
03
Specific Needs
Supplements target different issues like weight gain, joint health, digestion, or immunity. Choose based on your pet's age, health status, and diet.
04
Safety and Dosing
Products should have clear dosing instructions and be safe for long-term use. We checked for potential interactions with medications.
05
Brand Reputation
We favored brands with transparent sourcing, veterinary input, and a track record of safety. Customer service and satisfaction ratings mattered.
06
Value for Money
current pricing we looked for effective products that deliver results without breaking the bank. Cost per serving was considered.
Living With It
Care, Cost and Maintenance
Consult Your Veterinarian First
Always discuss supplements with your vet, especially for pets with health conditions or on medication. They can recommend appropriate dosing and flag interactions.
Start Slowly and Monitor
Introduce one supplement at a time. Watch for adverse reactions like vomiting, diarrhea, or changes in appetite. Discontinue if issues arise.
Store Properly
Keep supplements in a cool, dry place away from direct sunlight. Follow expiration dates. Some gels may need refrigeration after opening.
Pro tip
When choosing a supplement, always check the active ingredient concentration per dose and match it to your pet's weight. Many products provide a dosing chart, but we recommend confirming with your vet for precise amounts.
Frequently asked questions
Can I give multiple supplements at once?
Generally yes, but avoid overlapping active ingredients. For example, don't combine two multivitamins. Always consult your vet to prevent over-supplementation.
Are these supplements safe for puppies or kittens?
Most are formulated for adult pets. For puppies or kittens, use products specifically labeled for growth. Check with your vet first.
How long does it take to see results?
It varies. Calorie gels may show weight gain in days to weeks. Multivitamins and mushroom supplements may take several weeks for noticeable benefits. Consistency is key.
Can I use these with prescription diets?
Yes, but check with your vet. Some supplements may interfere with therapeutic diets (e.g., renal or urinary). Your vet can advise on compatibility.
What if my pet refuses to take the supplement?
Try mixing with a small amount of wet food or a treat. For gels, you can smear it on the paw or inside the cheek. If refusal persists, consider a different form (powder vs. gel).
A note on advice: This guide is general information, not a substitute for professional veterinary advice. Talk to your vet before changing your dog's diet or care routine, especially if your dog has allergies, kidney disease, pancreatitis, obesity, heart disease or any other medical condition.
Transparency
How we made this guide
How we chose. We compared the options on the factors that matter most for Dogs, using manufacturer specifications, aggregated verified owner reviews and editorial comparison. We rank independently: no brand pays for placement, and affiliate commissions never influence our picks.
How it was written. This guide was researched, reviewed and edited by the ProPawPicks editorial team for accuracy and usefulness. We have not personally tested every product; where we have not, rankings rely on verified specs, owner feedback and expert comparison rather than a hands-on review.
Affiliate disclosure. ProPawPicks is reader-supported. If you buy through links on our site, we may earn a commission at no extra cost to you. See our affiliate disclosure.
Keep Reading
More Dogs guides
Interactive Dog Toys, ComparedView picks →Invisible Dog Fence for Sensitive Stomachs: 2026 Top Pick ReviewedView picks →Expert Picks: Best Invisible Dog Fence for the Money 2026View picks →Invisible Dog Fence under 50 That Hold UpView picks →The Best Invisible Fence for Dog WirelessView picks →Buying Guide: Best IP Cameras for Baby Pets (2026)View picks →
Sources and further reading
Some links below are affiliate links. If you buy through them we may earn a small commission at no extra cost to you. Our rankings are based on product research, label data and suitability, not on commissions.