As pet owners, we see advertisements in magazines, TV, and the internet about all kinds of dog supplements. Many of them make huge claims we wish were true. But the reality is not all these claims are accurate. Some supplements are a waste of money, and can actually be harmful to your pet, while others can be quite effective. It’s important to learn which supplements are useful and under what circumstances.

Dog with dietary supplements bottle

When Should I Consider Dietary Supplements for My Dog?

While additional supplementation is not typically necessary for healthy dogs fed a nutritionally well-balanced, commercial diet, dogs with certain medical conditions may benefit from supplements. Additionally, some supplements help slow the progression of certain medical conditions, so they are recommended even for healthy pets.

The best way to know what supplements are best for your dog and which specific brands are of the highest quality is to speak with your veterinarian. They will select supplements based on your dog's age, any medical issues they have, their diet, and more.

Understanding what common medical conditions may benefit from supplementation helps you know when it is time to speak to your veterinarian. The following are situations where your dog may benefit from supplementation to help them live a healthy and happy life.

Dog Supplements for Stress

Some dogs, just like people, live in a constant state of stress, whether a result of separation anxiety, a chronic illness, or other factors. As humans, we know the negative impact stress can have on our health, and the same applies to our dogs. When stress occurs, there is an ongoing release of cortisol, a stress hormone. Excess cortisol leads to inflammation as well as harming the digestive system. Chronic inflammation in the body can contribute to arthritis, and poor digestion can lead to improper absorption of nutrients. Supplements that may help include:

  • Vitamin B1, L-theanine, L-tryptophan, and colostrum have all been found to help ease stress. 
  • Both Vitamin C and Vitamin E have been found to reduce inflammation. 
  • Prebiotics and probiotics help maintain proper gut flora and aid in digestion. 
  • Vitamin B12 can aid with digestion or require supplementation if reduced by intestinal disease.

By combatting the stress and its negative side effects, you can potentially improve your dog's quality of life with supplements.

Dog Supplements for Osteoarthritis

Osteoarthritis, or OA, is a painful condition caused by “wear and tear” of cartilage and other parts of the joints that may result in physical and emotional changes or signs in your dog. OA does not just come with old age–it affects dogs of all ages, sizes, and breeds[1,2]. Joint injuries, obesity, and congenital joint conditions can contribute to the development of arthritis.

How can supplements help dogs with osteoarthritis?

  • Joint Supplements
    Veterinary orthopedists recommend starting dogs on joint supplements around two years of age. These joint supplements contain ingredients such as glucosamine, MSM, and chondroitin sulfate. All three are anti-inflammatory mediators that are highly beneficial for dogs since inflammation is a huge factor in the development of arthritis. 
  • Vitamin C and E
    These two vitamins may help reduce inflammation.
  • Fish Oil
    Among its many benefits, fish oil is anti-inflammatory when given in appropriate quantities.
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Dog Supplements for Gastrointestinal Conditions

A healthy gastrointestinal (GI) tract is critical to a dog's immune system since the GI tract comprises 70% of the immune system[3] It's where nutrients are absorbed so the remainder of the body can function properly. When illness affects the GI tract, nutrients cannot be properly digested and absorbed. If this occurs, deficiencies in essential micronutrients can result.

  • Prebiotics and Probiotics
    Two common types of supplements recommended for dogs suffering from gastrointestinal issues are prebiotics and probiotics. By boosting healthy gut bacteria and releasing short-chain fatty acids, they can improve digestion[4].
  • Vitamin B12
    This is also a very common supplement given when dogs are having intestinal issues which affect nutrient absorption. Vitamin B12 deficiencies can cause issues with your dog’s blood cells, nerve cells, intestinal health, and brain function.
  • Fiber Supplements
    Adequate fiber intake is important for good gastrointestinal health in general, and most dogs get what they need if fed a high-quality commercial dog food. Extra fiber supplementation may help dogs with certain fiber-responsive digestive issues.
  • Other Supplements
    Additional supplements with potential GI anti-inflammatory effects are:
    • Omega-3 fatty acids found in fish oil
    • Glutamine
    • Curcumin
    • Vitamins C and E

Dog Supplements for Allergies

When dogs suffer from allergies, they can have issues with their skin, ears, and gastrointestinal tracts. In addition to appropriate medication treatment, proper supplementation may help reduce allergy signs and improve skin, ear, and GI tract health.

  • Fish Oil
    Fish oil has anti-inflammatory benefits. 
  • Vitamins C and E
    These vitamins are another common recommendation for dogs with allergies.
  • Magnesium
    Magnesium helps reduce inflammation and can potentially help reduce anxiety and calm the nervous system.
  • L-theanine
    This helps ease anxiety that is often associated with licking, biting, and chewing.
  • Probiotics
    As noted above, having a healthy gastrointestinal tract is critical to a strong immune system.

Dog Dietary Supplement Safety and Efficacy

  • Remember, never give your dog supplements without consulting with your veterinarian. When used properly, supplements may be beneficial. However, when not given appropriately, they can harm your dog.
  • Only use high-quality supplements that meet safety standards.
  • Look for lot numbers on the package. A lot number is an indicator that the company complies with all control checks and safety standards.
  • Because many supplements formulated for human consumption contain ingredients that can be toxic to dogs, it’s generally not recommended to use human supplements without first checking with your veterinarian.

As with human supplements, there can be significant variability in content and quality of supplements and how much efficacy information is available. Your veterinarian can suggest trustworthy manufacturers of high-quality supplements with studies showing they work, when available. Supplements often haven’t been scientifically studied and shown to work for the conditions they’re used to treat, or in conjunction with other supplements or medications to know how they might interact, so have your veterinarian help select appropriate supplements and doses for your dog when considering supplementation.


Melody R. Conklin, VMD, MBA

Dr. Melody R. Conklin is originally from Youngsville in northwestern Pennsylvania and earned her BS at The Pennsylvania State University, University Park in 2003, where she majored in Animal BioScience and minored in Wildlife and Fisheries Science. She then attended the University of Pennsylvania, earning her VMD in 2007. Dr. Conklin worked in companion animal general practice until 2015 when she joined Zoetis’ Veterinary Medical Information and Product Support department while finishing her MBA at Penn State Great Valley in 2017. Dr. Conklin currently works full-time in a companion animal practice while working with Zoetis US Petcare Medical Affairs in a consultant role. She lives in Sinking Spring, PA with her 4 cats, Vegeta, Fluffzor, Poof, & Butter, and 3 guinea pigs, Pascha, Elena, & Caroline.

  1. Dietary Supplement Use Among Adults: United States, 2017-2018. Centers for Disease Control and Prevention. Accessed Sept. 20, 2021
  2. Arthritis in Dogs: A Guide for Pet Parents. Parnell. Accessed Sept. 20, 2021.
  3. Supplements and Treatment for Canine Arthritis and Mobility Issues. Preventive Vet. Accessed Sept. 20, 2021.
  4. The Power of Probiotics. College of Veterinary Medicine. Accessed Sept. 20, 2021.