How to Choose a Safe Pet Supplement: Reading the Label

Start by asking whether your pet needs one. AAFCO says healthy dogs and cats on a complete and balanced diet for their life stage generally do not. If you and your vet decide pet supplements make sense, the label tells you most of what matters.

That means the species it is made for, what is in it, how much to give and who made it. Below is a checklist you can use in the store or on a product page, with the reason behind each point.

Does my pet need a supplement at all?

For most healthy pets, the food already does the job. AAFCO's consumer guide puts it plainly: healthy dogs and cats fed a complete and balanced diet appropriate for their life stage generally do not need supplements.

The Cornell Feline Health Center agrees for cats, saying supplements are usually not necessary on a balanced and complete diet. Cornell adds that supplements can be harmful and should not be given without a veterinarian's approval.

The ASPCA's nutrition pages for both cats and dogs say a vitamin supplement is unnecessary on a complete and balanced diet unless a vet diagnoses a specific deficiency.

How do you know the food is complete? The FDA explains that a food labeled "complete and balanced" meets an AAFCO nutrient profile or has passed an AAFCO feeding trial. It is meant to be a pet's sole diet.

None of this means a supplement is never useful. AAFCO notes that a veterinarian may safely recommend specific supplements to go along with the food. We've looked at the question for each species in do cats need vitamins and do dogs need vitamins.

Who checks pet supplements before they're sold?

Here's a fact worth knowing before you shop: in the US there is no legal category called "dietary supplement" for animals. The FDA says products marketed that way for pets don't fall under DSHEA, the law that covers human supplements.

Instead, the FDA regulates them either as food for animals or as animal drugs, depending on their ingredients and intended use. The FDA also notes that food for animals doesn't need its pre-market review to be sold, unless an ingredient is a food additive.

AAFCO, which develops model language that states may adopt in their feed laws, says animal feed supplements are not like human dietary supplements. The FDA points out that AAFCO itself has no regulatory authority. Your state and the FDA do the enforcing.

So there is no government sign-off on each product before it goes on sale. The label is the part you can check yourself, which is why it's worth knowing how to read one.

What should dog supplements and cat supplements say on the label?

AAFCO's guide to reading pet food labels sets out what a label has to show. It is a useful yardstick for dog supplements and cat supplements too. These are the points to look for, and why each one matters.

On the label	What to look for	Why it matters
Species	"For dogs," "for cats," or both	AAFCO requires a label to say which species a food is for. Different species need different amounts of nutrients.
Feeding statement	"Complete and balanced," or "intended for intermittent or supplementary feeding only"	AAFCO says the second wording means the product doesn't meet the standard for a complete diet, so it is an extra.
Ingredients	A full list, heaviest first	AAFCO requires ingredients in descending order by weight, so the first one listed makes up the most.
Nutrient guarantees	Minimum protein and fat, maximum fiber and moisture, plus any nutrient the product is sold for	AAFCO lists these four as the basic required guarantees.
Feeding directions	An amount by body weight	AAFCO asks owners to follow the label directions, or the dose their vet sets.
Calorie content	kcal per kg and per piece, scoop or pouch	AAFCO requires it under a "Calorie Content" heading. Extras count toward your pet's daily calories.
Who made it	A company name with city, state and zip	AAFCO generally requires the name and address, so you know whom to contact.

One detail worth knowing: AAFCO notes that a complete food's label typically lists only crude protein, fat, fiber and moisture. So the bag usually can't tell you how much of other nutrients your pet already gets. Your vet can help fill that gap.

What does the NASC Quality Seal mean?

The National Animal Supplement Council describes itself as a nonprofit trade association of supplement makers, so it is an industry body rather than a regulator.

NASC says companies earn its Quality Seal by passing a facility audit every two years and random independent product testing to check that products meet their label claims. That's a useful signal about how a company is run.

The FDA adds a caution: seals or endorsements from outside organizations do not assure that a food is nutritionally adequate. The seal speaks to quality checks, and your vet still decides whether your pet needs the product.

What are the red flags on a supplement label?

A few things should make you put the product back, or at least ask your vet first.

• Promises to cure or treat a disease. The FDA says a product intended to treat or prevent a disease is a drug. AAFCO warns that many supplements claim or imply they will mitigate, treat or prevent diseases, and that such claims misbrand an animal feed product.
• No company name or address on the pack.
• No feeding directions, or directions that don't match your pet's weight.
• A product made for people. Merck's veterinary manual lists iron and vitamin D among the ingredients of concern when pets get into human multivitamins, and names xylitol among substances that may be toxic to animals.
• Several products that add the same nutrients. AAFCO says supplementing a complete diet risks exceeding the upper limits of certain nutrients.

More is rarely better. Merck advises that indiscriminate mineral supplementation should be avoided because it can cause a mineral imbalance, and notes that very high doses of vitamin E can interfere with absorption of the other fat-soluble vitamins.

The ASPCA's dog page warns that over-supplementation makes poisoning from excess vitamins more common. It says excess vitamin A may result in bone and joint pain, brittle bones and dry skin.

Powder, chew, liquid or stick: does the format matter?

We found no veterinary source that compares formats, so there's no evidence that one works better than another. What matters is that the product is right for your pet's species and that your pet will actually eat the amount on the label.

The FDA notes that treats, snacks and supplements are typically not intended to be a pet's sole diet. A flavored chew, paste or liquid carries calories of its own, which is why the calorie line on the label matters.

Cornell's rule of thumb for cats is to keep extras to 10 to 15 percent of daily calories. The ASPCA suggests 5 percent or less of daily food intake for both cats and dogs. A flavored supplement with a calorie line belongs inside that allowance.

Formats mainly differ in how you give them. A lickable paste can go straight from the stick or on top of a meal, a liquid can be poured into a bowl, and a soft chew can be handed over like a snack.

To see these points on real labels, the Choolip shop lists lickable purée sticks, a lactose-free milk and plant-based bites (the bites are for dogs only). Whichever brand you look at, ours included, run it through the checklist above first.

When should I ask my vet before starting a supplement?

AAFCO says pet owners should always talk to their veterinarian before introducing supplements, then use the vet's dosage and follow the label. In practice that conversation is most useful when:

• your pet is a growing kitten or puppy. The FDA explains that AAFCO sets a separate nutrient profile for growth, so an adult product may not fit
• your pet already eats a complete food and you're thinking of adding a vitamin or mineral product
• you want to give more than one supplement at once
• the product is for a different species, or for people

It helps to bring the product, or a photo of its label, so your vet can see the exact ingredients and amounts. For single nutrients, our guides to taurine for cats, omega-3 for dogs and probiotics for dogs cover what the research shows.

Call your vet promptly if:

• your pet gets into a human vitamin or supplement. Merck's veterinary manual says all active and inactive ingredients need to be considered, and that iron and vitamin D are among the main concerns
• your pet eats much more of a supplement than the label amount
• anything about your pet seems off after starting a new product

The ASPCA Animal Poison Control Center can also be reached at (888) 426-4435.

Questions new pet parents ask

Do pets need supplements if they eat a complete food?

Generally not, according to AAFCO, Cornell and the ASPCA. A vet may recommend one for a specific reason.

Are pet supplements approved by the FDA?

No. The FDA regulates them as animal food or as animal drugs depending on their ingredients and intended use, and food for animals doesn't need pre-market review unless it contains a food additive.

Can I give my dog or cat my own vitamins?

Ask your vet first. Merck's manual lists iron and vitamin D among the concerns when pets swallow human multivitamins, and some human products contain xylitol.

What does the NASC seal on dog supplements mean?

NASC, an industry trade association, says its seal requires a facility audit every two years and random independent testing against label claims.

Is a bigger dose better?

No. AAFCO warns that supplementing a complete diet risks exceeding the upper limits of certain nutrients. Stick to the label or your vet's dose.

Sources

• AAFCO: Supplements
• AAFCO: Reading Labels
• FDA Center for Veterinary Medicine: FDA's Regulation of Pet Food
• FDA Center for Veterinary Medicine: Complete and Balanced Pet Food
• Cornell Feline Health Center: Feeding Your Cat
• ASPCA: Cat Nutrition Tips
• ASPCA: Dog Nutrition Tips
• ASPCA: Cold Weather Safety Tips (Animal Poison Control number)
• Merck Veterinary Manual: Nutritional Requirements of Small Animals
• Merck Veterinary Manual: Toxicoses in Animals From Human Multivitamins and Supplements
• National Animal Supplement Council (industry trade association): For Animal Lovers

This article is for general information and is not veterinary advice. Talk to your vet about your own pet — they know the animal in front of them.