The world of dog supplements is vast. You can find almost any human supplement in a dog version: multivitamins, fish oil, and even CBD. However, most dogs don't require additional nutrients if they're fed nutritionally complete and balanced food appropriate for their life stage. That said, some of the best dog supplements can benefit dogs with certain ailments and health issues, including diarrhea, joint pain, itchy skin, and anxiety.
To determine what supplements are worth giving your dog, we extensively researched which ingredients hold canine health benefits, spoke with three veterinarians, and evaluated dozens of products. Our top pick is Pet Honesty Wild Caught Omega-3 Fish Oil, which research proves packs many benefits, from lowering inflammation to improving skin and coat health. This supplement has excellent overall safety and has undergone extensive third-party testing.
Like with human supplements, there's no regulation or oversight confirming what ingredients are actually in a supplement or its safety. All of our experts emphasize the importance of buying a supplement with science-backed ingredients from a trusted brand that's been third-party tested. Talking to your vet before giving your dog any supplements is also necessary. The wrong dosage or ingredients could make their health issue worse or work against medication they're already on.
Read more about how Insider Reviews tests and evaluates pet products.
Our top picks for the best dog supplements
Best overall: Pet Honesty Wild Caught Omega-3 Fish Oil
Best probiotics: Nutramax Proviable-DC Digestive Health Supplement
Best calming: Vetriscience Composure
Best joint chew: Vetoquinol Flexadin Advanced with UC-II Chews for Cats and Dogs
Best CoQ10 for heart health: Vetriscience Conenzyme Q10
Best vitamin B supplement: ThorneVet B ComplexVET
Best overall
This third-party-tested pure fish oil contains four marine-based oils rich in omega fatty acids, which experts say provide anti-inflammatory benefits and are the best ingredients to ease joint pain in dogs.
- Beneficial for healthy dogs as well as those with inflammatory conditions
- Highest concentrations of total omega-3 fatty acids, EPA, and DHA
- Reasonable cost per dose
- No added flavors
- No overpowering fishy odor
- Easy to use as a meal topper
- Large bottle lacks pump dispenser and pour spout
- Refrigeration is recommended by our experts
- Higher in calories (41 kcal per teaspoon)
- Shorter shelf life may lead to waste with small or medium dogs
Our top pick for the best dog supplements is Pet Honesty Wild Caught Omega-3 Fish Oil. Fish oil supplements can be highly beneficial for all dogs, from helping treat inflammatory conditions like arthritis or skin allergies to improving skin and coat health, says Dr. Anita Patel, director of clinical excellence, southeast for veterinary staffing service IndeVets.
This supplement is also our top recommendation for the best fish oil for dogs. It contains four types of marine-based oils, which research shows are the most beneficial sources of omega fatty acids to reduce inflammation. However, Patel says a balance of omega-6s and 3s is best. Since dog food formulas tend to be heavier on omega-6s, this omega-3 formulation helps achieve that ratio alongside the best dog food.
This fish oil is NASC-certified and independently tested by ConsumerLab to confirm potency, purity, and lack of mercury. We love that it doesn't have an overly fishy smell or taste. While it's easy to add as a dog food topper and to portion the correct dose for different-sized dogs, it lacks a pump for convenient dispensing. Keep in mind that fish oil comes with significant calories, so check with your vet on what dosage is best to balance calories and nutrition.
You'll need to store the fish oil in a refrigerator and use it within 45 days of opening, so it's smart to choose the smallest bottle for a smaller dog.
Best probiotics
This probiotic from a leading pet supplement brand contains expert-backed bacteria strains at a budget-friendly price, making it the best choice for most dogs.
- Contains research-backed bacteria strains plus prebiotics
- Third-party tested
- Affordable
- Safe for dogs and cats
- Capsule may be challenging to feed
Probiotics can benefit dogs with gastrointestinal issues, from diarrhea-causing viruses to chronic conditions like inflammatory bowel disease. Probiotic supplements add good bacteria to a dog's gut, lowering inflammation and speeding up their gut microbiome's recovery. However, best results are achieved when these supplements are given alongside a fiber-rich, complete and balanced dog food that fosters good bacteria, says Dr. Jan Suchodolski, associate director for research at the Texas A&M University Veterinary and Biomedical Sciences Gastrointestinal Laboratory. Beyond providing GI support, Patel says probiotics can improve a dog's oral health.
Our top pick for the best probiotics for dogs, Nutramax Proviable-DC Digestive Health Supplement, is a high-quality supplement that contains 5 billion CFUs (colony-forming units). CFUs are the live organisms that make probiotic supplements effective. Nutramax's supplement contains seven different strains of good bacteria recommended by our experts. More strains mean a greater diversity of microbes being reintroduced to a dog's microbiome.
While many probiotics must be refrigerated to keep the bacteria alive, Nutramax Proviable-DC doesn't, making it easier to store and travel with. It's also more affordable than many competitor products, NASC-certified, and third-party tested by ConsumerLab.
Best for calming
These tasty dog treats help calm your dog in stressful situations without any drowsy side effects.
- Fast-acting and long-lasting
- Ingredients are known to help alleviate stress
- NASC seal
- No artificial flavors
- Proprietary blend is unspecified
Whether your dog is chronically anxious or triggered by things like fireworks, thunderstorms, or visits to the vet, over-the-counter supplements can help keep your dog calm. Trusted by veterinarians and one of our recommendations for the best dog treats, Composure is formulated with thiamine (vitamin B1) to regulate the nervous system and manage stress, L-theanine to balance neurotransmitters and induce relaxation, and a proprietary biopeptide blend of proteins the brand claims have a relaxing effect on animals.
The chews work without a sedative effect, inducing tranquility but not drowsiness, and are said to kick in within 30 minutes and last for four hours. They're easy to give as a dog treat, and it's safe to give your dog double or triple the dose during extra-stressful situations (if your dog is under 25 pounds, check out the Composure for Small Dogs). They come in three flavors — chicken, bacon, and peanut butter — without any artificial flavors, and boast the NASC quality seal.
Best joint chew
These flavorful chews contain collagen that can reduce inflammation in dogs with arthritis.
- Contains science-backed canine joint inflammation reducers
- Easy to give
- Tasty fish flavor
- Good for multi-pet households since it’s safe for cats
- Potential for diarrhea, vomiting, lethargy in dogs with a sensitive GI tract
- Contains vitamin E, which is not recommended for dogs taking blood thinners
Dogs with arthritis or joint pain may benefit from Flexadin Advanced with UC-II Chews. The supplement's active ingredient is undenatured-type II collagen (UC-II), which our experts say helps reduce joint inflammation and potentially helps rebuild part of the joint cartilage. These chews also contain vitamin E and omega-3 fatty acids, both of which may offer anti-inflammatory benefits, and they're NASC-certified for quality assurance.
We love that these chews are a one-a-day treat with the same dosage for dogs of all sizes and cats, making them a win for multi-pet households. They come in a tasty fish flavor that many dogs will love. However, if your dog doesn't accept the chews, our guide to the best joint supplements for dogs has more options.
Best CoQ10 for heart health
VetriScience Coenzyme Q10 is well-tested for quality, comes at a low dose for small to medium dogs, and offers great value.
- Quality tested
- Well-priced
- Unflavored
- Easy to sprinkle on food
- Low dose per capsule not ideal for larger dogs
"Animals with heart disease may benefit from coenzyme Q10," Teller says. Often shortened to CoQ10, this substance is also known as ubiquinol or ubiquinone. Like all the other supplements in this guide, make sure to talk to your veterinarian about CoQ10 before giving it to your dog. That's because only certain heart conditions benefit from it, Teller says.
VetriScience Coenzyme Q10 is a formula that's been third-party tested by ConsumerLab and certified by the NASC for quality. Each capsule provides 10mg of CoQ10, and the brand advises one capsule per 10 pounds of body weight. This low dose per capsule makes it convenient for households with small dogs or pups of different sizes. However, if your dog is a large or extra large breed, you may want to opt for a higher-dose formula, like Dog Vites CoQ10 for Dogs 30 mg, rather than administering six-plus capsules per day.
The capsules are unflavored, which helps minimize reactions for dogs with food sensitivities or allergies. We also like that you can break open the capsule and sprinkle the CoQ10 over your dog's food if they don't like taking pills. Lastly, these supplements are affordably priced at roughly 15 cents per capsule.
Best vitamin B
ThorneVet B ComplexVET provides four active forms of B vitamins in naturally flavored poultry chews.
- Mix of B vitamins
- Trusted brand
- Affordably priced for small and medium dogs
- Only available in chicken flavor
- Can be expensive for larger dogs
Some dogs with gastrointestinal issues benefit from vitamin B supplements. This is especially true if they're having problems with malabsorption of their food. One sign of that would be chronically soft stools. "In these cases, vitamin B can be particularly helpful," Teller adds.
In general, there aren't as many options for B vitamin supplements for dogs, but this soft chew from ThorneVet contains a blend of vitamins B1, B2, B3, B5, B6, B12, folate, biotin, and choline for a well-rounded mix. It's specially formulated for digestive issues. Fun fact: It's suitable for cats and horses, too.
Formerly owned by the highly respected human supplement brand Thorne, ThorneVet is well-known and trusted in the animal supplement space for the rigorous quality control behind its ingredients and formula. It's no surprise, then, that their pet supplements have the NASC seal.
In terms of cost, one container of 60 chews will last most medium-sized dogs a month since Thorne recommends one soft chew per day per 25 pounds of body weight. If you have a larger dog, this could get pricey. But overall, the price of this supplement makes sense for the quality.
What to look for in dog supplements
Just like human supplements, the pet supplements industry isn't regulated by any governing body — which means there are no mandated quality or safety checks. So, it's essential to know what factors to consider to ensure your pet's health and well-being before giving them dog supplements.
Your veterinarian's advice: Some vitamins and minerals aren't safe to use with certain medications, may not be safe for small dogs, or could exacerbate issues if your dog is already getting enough of the same nutrient in their food. Your veterinarian can provide tailored advice based on your dog's specific health needs and conditions. Many vets sell supplements in their offices. If you prefer to buy supplements from a trusted pet retailer, your vet can still recommend what to look for and brands they trust.
Appropriate formulations and dosages: Different supplements cater to different needs, from joint health to digestive support. Some help bolster healthy dogs, while others are formulated for dogs with specific diseases or issues. Pay close attention to what exact concerns a formula purports to help. And keep in mind that more isn't always better. Patel says vitamin and mineral overdose is a real concern, even in healthy adult dogs. The highest risk is overdoing fat-soluble vitamins (A, D, E, and K), usually in large doses, and over-supplementation of minerals such as calcium, which can lead to orthopedic abnormalities, especially among large dog breeds that aren't fully grown.
Active ingredients: It's crucial to know what active chemical compounds, both natural and synthetic, are in a supplement to ensure they are effective and safe for your pet. Which active ingredients work best depends on the issue and goal at hand. For each type of supplement in this guide, we explain why the active ingredients are effective.
Added flavors and other ingredients: Flavoring isn't always an important factor, but it's something to consider. "Pet supplements often have flavoring in them for taste — chicken, beef, or fish flavoring being most common — and these will disrupt any pet that is on a food trial for allergies, potentially causing more harm than good," says Dr. Michelle E. Matusicky, a veterinarian and clinical assistant professor at the Ohio State University College of Veterinary Medicine. Of course, in some cases, flavoring might be a plus because it's easier to get your dog to eat the supplement. That said, we gave supplements without extra flavoring slightly higher marks than those that were flavored.
Third-party testing: Patel says that unregulated supplements can contain harmful chemicals and ingredients that can actually harm your pet. While there isn't a government stamp of approval on supplements, Patel says choosing brands that display the National Animal Supplement Council (NASC) seal is one of the best ways to ensure you're buying products from responsible sources, that ingredients and production standards are being met, and that a third party has evaluated the product. A product also gets a gold star if it has been tested and approved by ConsumerLab, an independent lab that tests supplements for purity, strength, disintegration, and brand integrity. These third-party organizations also look for contamination with lead, mercury, and other potential toxins. Another good organization that tests pet supplements is NSF International.
Price: A more expensive supplement does not always correlate with a higher-quality product. Of course, the flip side is also true. "Some supplements may be a little bit more expensive because they're putting in that extra research and quality control," Teller says.
One way we evaluated value was to look at the concentration of each supplement relative to its price. Supplements priced similarly to others but with much lower concentrations of key nutrients received lower ratings in our evaluation process. Supplements with higher concentrations of ingredients are likely to last longer since you'll need less of the supplement to reach your vet's recommended dose.
Health restrictions and age: Certain supplements, like multivitamins, during certain periods of pregnancy or adolescent growth can predispose your dog to health risks and growth disorders, Patel says. Also, if your dog is on blood thinners, you should avoid anything with methylsulfonylmethane (MSM) or large amounts of vitamin E. If your dog has food allergies, double-check the ingredients for added flavorings. If your dog is prone to digestive issues, ask your vet before giving fish oil, which can cause upset stomach or diarrhea.
How we selected the best dog supplements
To select the best dog supplements, we interviewed three veterinarians and evaluated dozens of products based on the following criteria. We also considered insight other veterinary experts shared for our guides to the best fish oils, probiotics, and joint supplements for dogs.
Based on their insights, we streamlined the most helpful, relevant, and evidence-backed supplement categories to support canine health. From there, we evaluated popular supplements for each category according to their ingredients, quality seals, and third-party testing. We then compared prices to determine their overall value.
Dog supplements FAQs
What is the best supplement for dogs?
In short, there's no single best supplement for dogs. Teller says the best supplement for your dog depends on their individual health and any other medications they might be taking. "It's really worth consulting with your veterinarian," she adds.
Should I give my dog supplements?
It depends on whether your dog has any health conditions that can be helped or harmed by supplements. "Certain health conditions such as osteoarthritis and certain advanced endocrine diseases may necessitate supplementation," Matusicky says. Meanwhile, Patel says growing dogs and pregnant dogs shouldn't take certain supplements, such as calcium. In short: Always ask your vet before starting your dog on a new supplement regimen.
Do vets recommend supplements for dogs?
"Supplements, in general, are completely unnecessary," Matusicky says. Specifically, multivitamins are a waste of money, Teller says. If your dog is eating high-quality dog food, they get all the nutrients a multivitamin would give them. But targeted supplements for specific health issues may be helpful, provided you have your veterinarian's approval.
What supplements are bad for dogs?
"In many instances, owners can do more harm than good to their animals with supplements, as even the most benign supplement can be dangerous if given at the wrong dose," Matusicky says.
Matusicky and Patel say some supplements should be avoided because too high a dose can overload your dog. These include fat-soluble vitamins (A, D, E, and K), minerals, especially calcium, CBD, and anything containing essential oils.
The bottom line with CBD is that though it's very trendy right now, Teller says we need more research on what it can do for dogs. "It may play a role in helping with arthritis and seizures in dogs with epilepsy," she says. However, there are major risks to getting the dose wrong, including liver injury and disease.
Essential oils are also popular and might be included in more homeopathic-type dog supplements, but Teller warns that dog owners should be especially careful with these. "Essential oils can be highly toxic to pets, and you definitely need to talk to your veterinarian about those," she says.
Lastly, many supplements can interfere with prescription medications your dog might be on for issues like immune, kidney, and liver diseases. "A lot of times, people start adding supplements and herbs on top, thinking it can't hurt," Teller says. "But in actuality, these can impact the absorption of medication that's been prescribed or cause an adverse reaction."
What is the best supplement for older dogs?
"As dogs age, they can develop any number of ailments," Matusicky says. "Depending on what's going on, different diets and supplements may be recommended." Some supplements are helpful for senior dogs with arthritis (omega-3s from fish oil) and "doggy dementia" (cognitive dysfunction blends) in particular, Teller says.
Should I give my dog probiotics?
Teller says veterinarians use probiotics frequently, particularly when dogs are dealing with diarrhea, have been on antibiotics, or are experiencing certain types of anxiety. But similar to how probiotics work in humans, the benefits are strain-specific, so you must pick the strain that helps with a specific health issue. Otherwise, the probiotic won't have an effect. "If you have an overall healthy animal, there's not a great indication for probiotics," Teller says.
What dosage should I give my dog?
Getting supplement dosage right is extremely important, Matusicky and Teller say. "A lot of times, supplements may not have enough or may have too much, and different conditions require different dosages," Teller says. "So it would be really a good idea to consult with your veterinarian about the condition you want to use that supplement for to make sure you're giving your dog the right dose."
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