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Dog supplements with the NASC seal

The NASC seal means the maker passed an independent quality audit and has its products randomly tested by an independent lab to confirm they match the label.1 32 brands we priced hold it, among them Native Pet, Zesty Paws, NaturVet and Wonder Paws. The best value with the seal for joints is PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor): 500 mg of glucosamine for a 50 lb dog for $0.19 a day.

PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor)

Best-value joint chew with the seal

PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor)

glucosamine 500 mgchondroitin 200 mgMSM 50 mg a day2 chews a day$0.19 a day2

$8.49 on Amazon
VetriScience Extra Strength Gut Health Capsules

Best-value probiotic with the seal

VetriScience Extra Strength Gut Health Capsules

15 billion CFU a day2 capsules a day$0.55 a day3

$32.96 on Amazon
Wonder Paws Omega Max 3x Fish Oil

Best-value fish oil with the seal

Wonder Paws Omega Max 3x Fish Oil

EPA + DHA 1,656 mg a day2 tsps a day$0.39 a day4

$36.95 on Amazon
VetriScience Veterinary Strength Calm & Confident, Chicken

Lowest-cost calming with the seal

VetriScience Veterinary Strength Calm & Confident, Chicken

L-theanine 25 mg a day1 chew a day$0.60 a day5

$36.04 on Amazon
Pet Naturals Allergy Plus Calming Soft Chews

Lowest-cost allergy chew with the seal

Pet Naturals Allergy Plus Calming Soft Chews

colostrum 5 mg100 million CFU a day1 chew a day$0.20 a day6

$12.10 on Amazon

Best value per job, for a 50 lb dog, among products from makers with the seal. Rules are printed under each table. Prices on Amazon, October 28, 2026.7

A grey greyhound standing in profile against a blue backdrop

The NASC Quality Seal

What we found

Companies with the sealNASC member list173 of 260
Products listed hereof 250 we priced91
Brandswith products here32
Joint, best valueglucosamine for a 50 lb dog$0.19
Probiotic, best value15 billion CFU a day$0.55

Cost a day = label dose for a 50 lb dog at the Amazon price, October 28, 2026.

What the NASC Quality Seal means

NASC is the National Animal Supplement Council. It gives the seal to member companies that pass an independent quality audit and keep meeting its rules. The rules include a written quality control manual, a system for logging adverse events and complaints, strict labeling rules, caution statements on labels for certain ingredients, annual training, and random product testing by an independent lab to confirm products match their label claims. Companies must pass an independent audit to show it.1

173 of the 260 companies on NASC's member list have permission to show the seal on supplements.8 The seal is about how the maker runs quality. It does not say how much of an ingredient a dog needs, so use the per-day amounts below to compare. Our joint, probiotic, fish oil and calming pages also show the seal for every product.

Joint supplements with the seal

Best value with the seal: PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor), glucosamine 500 mg · chondroitin 200 mg · MSM 50 mg a day for $0.19.2 The label says 4 chews a day for the first 4 to 6 weeks, then the 2 chews a day shown here. How we pick: the lowest cost a day that reaches 330 mg of glucosamine for a 50 lb dog, the same rule as our joint supplement page.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Joint supplements with the seal for a 50 lb dog
ProductGlucosamine, chondroitin and more a dayServings a dayCost a day
PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor) best valueglucosamine 500 mg · chondroitin 200 mg · MSM 50 mg2 chews$0.19 a day
VetIQ Glucosamine Hip & Joint Chews with MSM and Krillglucosamine 600 mg · MSM 210 mg · EPA + DHA 74 mg2 chews$0.28 a day
Purina Pro Plan Veterinary Supplements Joint Care, Medium/Large dogs, soft chewsglucosamine 245 mg · chondroitin 160 mg · EPA + DHA 60 mg1 chew$0.67 a day
NaturVet Glucosamine DS Plus Level 2 Moderate Care Soft Chews (dogs and cats)glucosamine 750 mg · chondroitin 90 mg · MSM 750 mg3 chews$0.72 a day
Zesty Paws Hip & Joint Bites—2 chews$0.73 a day
Pet Honesty Hemp Hip + Joint Health Senior Soft Chews (Chicken)glucosamine 800 mg · MSM 300 mg · green-lipped mussel 400 mg2 chews$0.96 a day
Greenies Supplements Hip & Joint Soft Chews, Chicken Flavorglucosamine 1,000 mg · chondroitin 800 mg2 chews$1.13 a day
PetLab Co. Joint Care Chews (Pork)glucosamine 600 mg · green-lipped mussel 100 mg1 chew$1.20 a day
Native Pet Hip + Joint Advanced Caregreen-lipped mussel 600 mg2 scoops$1.67 a day

Probiotics with the seal

Best value with the seal: VetriScience Extra Strength Gut Health Capsules, 15 billion CFU a day for $0.55.3 How we pick: the lowest cost per billion CFU among products that name their strains, the same math as our probiotic page and our Native Pet review.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Probiotics with the seal for a 50 lb dog
ProductProbiotic CFU a dayServings a dayCost a dayCost per billion CFU
Pet Naturals Daily Probiotic Soft Chews240 million CFU2 chews$0.23 a day$0.94 CFU
Native Pet Probiotic Powder6 billion CFU1 scoop$0.50 a day$0.08 CFU
VetriScience Extra Strength Gut Health Capsules best value15 billion CFU2 capsules$0.55 a day$0.04 CFU
Pet Honesty Probiotics, Gut + Immune Health Soft Chews with Digestive Enzymes, Pumpkin6 billion CFU2 chews$0.59 a day$0.10 CFU
Zesty Paws Daily Probiotic Bites6 billion CFU2 chews$0.73 a day$0.12 CFU
Native Pet GutWell Power Poop1 billion CFU2 scoops$1.00 a day$1.00 CFU
Purina Pro Plan Veterinary Supplements FortiFlora Canine Probiotic100 million CFU1 packet$1.03 a day$10.33 CFU
Vetoquinol Pro-Pectalin Chewable Tablets1.5 billion CFU2.5 tablets$1.25 a day$0.83 CFU
Purina Pro Plan Veterinary Supplements Multi Care Canine Soft Chews600 million CFU3 chews$2.00 a day$3.33 CFU
Purina Pro Plan Veterinary Supplements FortiFlora Canine Probiotic (30 sachets)100 million CFU1 packet$2.07 a day$20.66 CFU
Pawfy Probiotics Soft Chews (Turkey & Bacon)5 billion CFU2 chews$2.33 a day$0.47 CFU

Fish oil with the seal

Best value with the seal: Wonder Paws Omega Max 3x Fish Oil, EPA + DHA 1,656 mg a day for $0.39.4 How we pick: the lowest cost for the same amount of EPA + DHA (cost per 1,000 mg), the same ranking as our fish oil page.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Fish oil with the seal for a 50 lb dog
ProductEPA + DHA a dayServings a dayCost a dayCost per 1,000 mg
Pet Health Solutions Omega-Caps HP Fish OilEPA + DHA 445 mg0.5 capsules$0.14 a day$0.31 EPA + DHA
Nutri-Vet Fish Oil SoftgelsEPA + DHA 300 mg1 capsule$0.18 a day$0.61 EPA + DHA
Vetoquinol Triglyceride OMEGA LiquidEPA + DHA 600 mg2 pumps$0.19 a day$0.32 EPA + DHA
Wonder Paws Superhero Norwegian Salmon OilEPA + DHA 828 mg3 tsps$0.21 a day$0.26 EPA + DHA
Natural Dog Company Wild Alaskan Salmon Oil Formula—2 pumps$0.25 a day—
Wonder Paws Omega Max 3x Fish Oil best valueEPA + DHA 1,656 mg2 tsps$0.39 a day$0.23 EPA + DHA
Nordic Naturals Omega-3 Pet (soft gels)EPA + DHA 765 mg3 capsules$0.59 a day$0.78 EPA + DHA
Natural Dog Company Skin & Coat Omega ChewsEPA + DHA 168 mg2 chews$0.67 a day$3.96 EPA + DHA
Native Pet Omega Oil (Pollock & Salmon Oil)—6 pumps$0.86 a day—

Calming chews with the seal

Lowest cost with the seal: VetriScience Veterinary Strength Calm & Confident, Chicken, L-theanine 25 mg a day for $0.60.5 How we pick: the lowest cost a day among products that print an amount. See best calming chews.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Calming chews with the seal for a 50 lb dog
ProductMain amounts a dayServings a dayCost a day
NaturVet Quiet Moments Calming with Melatonin Soft Chews—2 chews$0.25 a day
VetriScience Veterinary Strength Calm & Confident, Chicken lowest costL-theanine 25 mg1 chew$0.60 a day
Pet Wellbeing Melatoninmelatonin 3 mg1 ml$0.64 a day
Zesty Paws Calming Bites (All Ages), Peanut Butter—2 chews$0.78 a day
Greenies Supplements Calming Chews, Chicken FlavorL-theanine 220 mg2 chews$0.85 a day
Pet Honesty Hemp Calming Max Strength Soft Chews (duck)melatonin 1.3 mg2 chews$0.96 a day
Native Pet Calm Air-Dried ChewsL-theanine 100 mg · melatonin 10 mg2 chews$1.00 a day
Purina Pro Plan Veterinary Supplements Calming Care (canine)—1 packet$1.13 a day

Allergy and itch chews with the seal

Lowest cost with the seal: Pet Naturals Allergy Plus Calming Soft Chews, colostrum 5 mg · 100 million CFU a day for $0.20.6 How we pick: the lowest cost a day among products that print an amount. See best allergy chews.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Allergy and itch chews with the seal for a 50 lb dog
ProductMain amounts a dayServings a dayCost a day
Pet Naturals Allergy Plus Calming Soft Chews lowest costcolostrum 5 mg · 100 million CFU1 chew$0.20 a day
PetArmor Antihistamine Allergy Relief (diphenhydramine HCl 25 mg)—4 tablets$0.28 a day
Vet's Best Shed + Itch Healthy Coat Chewable Tabletsomega-3 100 mg2 tablets$0.32 a day
Vet's Best Seasonal Allergy Soft Chews—1 chew$0.50 a day
Zesty Paws Allergy & Immune Bites (Lamb)colostrum 200 mg · 500 million CFU2 chews$0.73 a day
Zesty Paws Omega Bites Skin & Coat (Chicken, AlaskOmega)—2 chews$0.73 a day
Zesty Paws Itch Relief Bites—2 chews$0.73 a day
Pet Honesty Allergy Support Soft Chews (Salmon)1 billion CFU · turmeric 400 mg · omega-3 58 mg2 chews$0.73 a day
Finn Allergy & Itch Soft Chewscolostrum 300 mg · 500 million CFU2 chews$0.76 a day
Native Pet Allergy Air-Dried Chewscolostrum 250 mg · 2 billion CFU2 chews$1.00 a day
Native Pet GutWell Itchy Skin1 billion CFU2 scoops$1.00 a day
PetLab Co. Allergy & Immune Probiotic Chews (Small Dogs)colostrum 350 mg · 1 billion CFU · omega-3 68 mg1 chew$1.27 a day

Urinary supplements with the seal

Lowest cost with the seal: Wonder Paws Superhero Urinary Tract Support with Cranberry Chewable Tablets (Bacon), cranberry 500 mg a day for $0.17.9 How we pick: the lowest cost a day among products that print a cranberry amount.

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Urinary supplements with the seal for a 50 lb dog
ProductCranberry a dayServings a dayCost a day
Wonder Paws Superhero Urinary Tract Support with Cranberry Chewable Tablets (Bacon) lowest costcranberry 500 mg2 tablets$0.17 a day
Nutri-Vet Bladder Control Chewablescranberry 50 mg2 chews$0.41 a day
Zesty Paws Urinary Tract Bites Soft Chews, Baconcranberry 400 mg2 chews$0.73 a day
Native Pet Bladder Chewscranberry 400 mg2 chews$0.83 a day
Pawfy Dog Eye Support Chews with Lutein & Cranberry, Peanut Buttercranberry 50 mg2 chews$2.33 a day

Digestive, pumpkin and anal gland products with the seal

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Digestive, pumpkin and anal gland products with the seal for a 50 lb dog
ProductMain amounts a dayServings a dayCost a day
Wonder Paws Superhero Pumpkin with Sweet Potato, Apple & Enzymes (Organic Pumpkin)pumpkin 3,400 mg2 scoops$0.66 a day
Zesty Paws Scoot Away Bites Gut Health (Chicken)—2 chews$0.73 a day
NaturVet Digestive Enzymes with Pre & Probiotic Soft Chews (Bacon & Chicken)—3 chews$0.75 a day
Fera Pets Pumpkin Plus Fiber Supplement Powder—2 tsps$0.78 a day
Veterinary Formula Anal Gland Support Soft Chews (Pork)—3 chews$0.85 a day
Vet Classics No Scoot Soft Chewspumpkin 40 mg5 chews$1.08 a day
Vetnique Glandex Anal Gland Health Soft Chews with Pumpkin Seed (Peanut Butter)960 million CFU2 chews$1.17 a day
Native Pet Organic Pumpkin Powder—2 scoops$1.33 a day
Native Pet WonderGland Anal Gland Fiber Topper1.5 billion CFU3 scoops$2.00 a day

Multivitamins with the seal

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Multivitamins with the seal for a 50 lb dog
ProductMain amounts a dayServings a dayCost a day
NaturVet VitaPet Senior Daily Vitamins (Immunity, with Calcium) Chewable Tablets—1 tablet$0.13 a day
Pet Naturals Daily Multi Soft Chews (Veggie)—1 chew$0.15 a day
NaturVet VitaPet Puppy Daily Vitamins with Breath Aid Soft Chews—1 chew$0.18 a day
Nutri-Vet Multi-Vite Chewables (Liver Flavor)—2.5 tablets$0.28 a day
VetIQ Multivitamin Soft Chews (Hickory Smoke)—2 chews$0.40 a day
VetIQ Advanced 8-in-1 Puppy Multivitamin Soft Chews600 million CFU · DHA 84 mg2 chews$0.40 a day
PetNC Natural Care Senior Multi Daily Formula Chewables—3 tablets$0.46 a day
Natural Dog Company Senior Support Soft ChewsDHA 8 mg2 chews$0.77 a day
PupGrade Daily Multivitamin, Beef Flavor Soft Chews—1 chew$0.83 a day
PetLab Co. Multivitamin Chew (22-in-1), Pork Flavor—1 chew$0.98 a day
Wholistic Pet Organics Canine Complete Enhanced Multivitamin (all-in-one powder)—1.5 scoops$1.17 a day
Native Pet The Daily Dog Vitamins and Supplements - 11-in-1 Multivitamin Powder4 billion CFU · DHA 240 mg · cranberry 194 mg · glucosamine 950 mg2 scoops$1.17 a day
Pawfy 15-in-1 Dog Multivitamin Soft Chews (Peanut Butter)—1 chew$1.17 a day
NaturVet Senior Advanced 5-in-1 Support Soft Chews with Turkey Tail Mushroom—4 chews$1.19 a day
Nutri-Vet Puppy-Vite Chewables for Puppies—5 tablets$1.51 a day
Native Pet Senior Daily Dog Vitamins & Supplements 12-in-1 Multivitamin4 billion CFU · DHA 370 mg · cranberry 680 mg2 scoops$2.00 a day

Liver, kidney, eye and other supplements with the seal

Each label's own dose for a 50 lb dog, cheapest first, at the Amazon price read October 28, 2026. Only products sold on Amazon by Amazon.com or the brand.

Liver, kidney, eye and other supplements with the seal for a 50 lb dog
ProductMain amounts a dayServings a dayCost a day
Ready Pet Go! Turmeric & Collagen Soft Chews (Chicken & Cheese)turmeric 400 mg · curcumin 110 mg1 chew$0.30 a day
Wonder Paws Superhero Milk Thistle liquid—1 ml$0.33 a day
NaturVet Urinary Care Cranberry Relief with Echinacea Soft Chews—1.5 chews$0.47 a day
Natural Dog Company Liver & Kidney (Milk Thistle + NAC) Soft Chews, Turkey—2 chews$0.67 a day
Zesty Paws Senior Advanced Vision Bites (Chicken)DHA 40 mg2 chews$0.95 a day
Angels' Eyes Natural Plus Tear Stain Soft Chews—3 chews$0.99 a day
VetriScience Liver Health Chews, Chickenturmeric 167 mg1.67 chews$1.10 a day
Pet Wellbeing Milk Thistle—2.75 mls$1.91 a day
Ocu-GLO PB Vision Supplement for Medium & Large Dogs (Powder Blend Capsules, XL)—2 capsules$1.92 a day
Ocu-GLO Vision Supplement for Small Dogs—2 capsules$1.98 a day
Pet Wellbeing Kidney Support Gold—3.5 mls$2.43 a day
Dr. Harvey's Kidney Health Support—6 scoops$2.88 a day

Dental chews and the seal

This page lists supplements. Dental chews such as Greenies and Dentastix are treats, and NASC's member list shows no treats seal for their makers, so we do not list them here. For dental chews, look for the VOHC acceptance instead: see the best dental chews for dogs.8

Questions people ask

What does the NASC seal mean on dog supplements?
It means the maker passed an independent quality audit and keeps meeting NASC's rules, including a system for logging adverse events and random product testing by an independent lab to confirm products match their labels.
Is the NASC seal real?
Yes. NASC is the National Animal Supplement Council, and its member list shows which companies have permission to show the seal. 173 of 260 members do. Companies must pass an independent audit to show it.
Which dog supplement brands have the NASC seal?
Among the products we priced: Angels' Eyes, Dr. Harvey's, Fera Pets, Finn, Greenies, Native Pet, NaturVet, Natural Dog Company, Nordic Naturals, Nutri-Vet, Ocu-GLO, Pawfy, Pet Health Solutions, Pet Honesty, Pet Naturals, Pet Wellbeing, PetArmor, PetLab Co., PetNC Natural Care, PupGrade, Purina Pro Plan, Ready Pet Go!, Vet Classics, Vet's Best, VetIQ, Veterinary Formula, Vetnique, Vetoquinol, VetriScience, Wholistic Pet Organics, Wonder Paws, Zesty Paws. Check the NASC member list for the current names.
What is the best joint supplement with the NASC seal?
PetNC Natural Care Hip & Joint Soft Chews (Liver Flavor): 500 mg of glucosamine a day for a 50 lb dog, at $0.19 a day.
What is the best probiotic with the NASC seal?
VetriScience Extra Strength Gut Health Capsules: 15 billion CFU a day for a 50 lb dog, at $0.55 a day.
Does Zesty Paws have the NASC seal?
Yes, and so does Pet Honesty. See Zesty Paws vs Pet Honesty for how they compare job by job.

Notes and sources

  • Amounts per day and servings per day come from each brand's label, read October 2026. See how we do the math.
  • Product photos come from Amazon.
  • Prices checked on Amazon October 28, 2026. Published .

Sources

  1. National Animal Supplement Council, "NASC Quality Seal" (independent quality audit, quality control manual, adverse event log, labeling rules, random product testing by an independent lab, annual training; the seal is earned, not offered for purchase), read October 28, 2026.
  2. PetNC Natural Care label: Hip & Joint Soft Chews (Liver Flavor), read October 2026.
  3. VetriScience label: Extra Strength Gut Health (formerly Vetri Mega Probiotic) Capsules, and cats, read October 2026.
  4. Wonder Paws label: Omega Max 3x Fish Oil (Alaskan salmon, cod liver, pollock, krill), read October 2026.
  5. VetriScience label: Veterinary Strength Calm & Confident, Chicken, 60 soft chews, read October 2026.
  6. Pet Naturals label: Allergy Plus Calming Soft Chews, read October 2026.
  7. Prices: Amazon product data, read October 28, 2026. Cost per serving = listing price divided by the servings in the container.
  8. National Animal Supplement Council, member list (a green check = permission to show the NASC Quality Seal), read October 28, 2026.
  9. Wonder Paws label: Superhero Urinary Tract Support with Cranberry Chewable Tablets (Bacon), read October 2026.

Labels for the products in the tables