Last month, my friend Sarah dropped $127 on a shopping cart full of supplements for her golden retriever, Max. Probiotics for his gut. Glucosamine for his joints. Fish oil for his coat. A multivitamin "just in case."
"He eats premium kibble," she told me, "but I want to make sure he's getting everything he needs."
Here's the thing: Max probably didn't need any of it.
The supplement industrial complex
The pet supplement industry has exploded into a $2.7 billion market in the U.S. alone, and it's projected to hit nearly $4 billion by 2030. Walk into any pet store and you'll find aisles of bottles promising shinier coats, stronger joints, better digestion, and boundless energy.
Multivitamins alone account for 35% of all pet supplement sales. That's a lot of pet parents convinced their dogs need extra nutrition.
But here's what most veterinarians will tell you: if you're feeding your dog a complete and balanced commercial diet, supplements are almost certainly unnecessary.
The uncomfortable truth about dog food
Modern commercial dog foods — the ones with that AAFCO (Association of American Feed Control Officials) statement on the bag — are already formulated to meet all your dog's nutritional needs. They contain the right balance of protein, fats, carbohydrates, vitamins, and minerals.
"Dogs fed an appropriate commercial diet should not require vitamin supplements unless recommended otherwise by a veterinarian," notes the American Kennel Club. Translation: your dog's food already has what they need.
The dirty secret? One veterinarian suggests that supplements exist largely because "dry dog foods are the reason we have a multi-billion dollar supplement industry for dogs." If you're feeding whole foods with adequate nutrition, supplements become redundant.
So when do dogs actually need supplements?
Here's where it gets nuanced. There are legitimate scenarios where supplements make sense:
Homemade diets: If you're cooking for your dog, you likely need supplements to ensure balanced nutrition. It's nearly impossible to nail the right nutrient ratios without professional guidance.
Diagnosed deficiencies: If your vet has identified a specific vitamin or mineral deficiency through bloodwork, targeted supplementation is necessary.
Certain health conditions: Dogs with joint issues, digestive problems, or other medical conditions may benefit from specific supplements like glucosamine or probiotics — but only under veterinary guidance.
Senior dogs: Older dogs sometimes need additional support for age-related issues, though again, this should be discussed with your vet.
Notice a pattern? Every legitimate use case involves veterinary oversight.
The risks nobody talks about
Here's what the supplement industry doesn't advertise: you can actually harm your dog by over-supplementing.
Supplements can have side effects just like pharmaceuticals. Too much of certain vitamins (especially fat-soluble ones like A, D, E, and K) can build up in your dog's system and cause toxicity. Excess calcium in large-breed puppies can lead to developmental bone problems. Human supplements containing zinc and iron can cause permanent damage to dogs.
And unlike prescription medications, supplements aren't tightly regulated. Quality varies wildly. That bottle of fish oil might contain exactly what it claims, or it might be rancid vegetable oil with a dog on the label.
"Veterinarians are advised by their governing body to be cognizant of content, efficacy and safety of these products," notes one medical review, adding that the lack of well-controlled studies makes this "a daunting task."
The bottom line for dog parents
Look, I get it. You want to give your dog the absolute best. The supplement aisle makes compelling promises, and our wellness culture tells us that more = better.
But the science doesn't back that up for healthy dogs eating quality food.
Before you drop a hundred bucks on supplements, ask yourself: Has my vet diagnosed a specific deficiency or condition? Am I feeding a balanced commercial diet? If the answers are "no" and "yes" respectively, save your money.
If you're genuinely concerned about your dog's nutrition, the best investment isn't a bottle of multivitamins — it's a conversation with your veterinarian. They can assess your dog's individual needs, review their diet, and recommend targeted supplementation only if it's actually necessary.
Because here's the real truth: sometimes the best thing you can give your dog is nothing extra at all.