Omega-3 fatty acids support cellular function, muscle activity, and more throughout the body. However, the body doesn’t produce omega-3s, so they must be obtained from food. Fish oil, which contains omega-3s in the form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is a popular supplement to give dogs, but not just for overall health. It’s thought to benefit dogs with conditions ranging from osteoarthritis to heart disease, and there’s some good evidence for its effects:
*The latest guidelines from the American College of Veterinary Internal Medicine (ACVIM), published in 2019, recommend omega-3 supplementation for dogs with current or past clinical signs of heart failure related to mitral valve disease, especially if they have decreased appetite, muscle loss or arrhythmia.
*A number of studies have indicated significant improvement of itchy skin and coat quality in dogs supplemented with fish oil.
*Omega-3 fatty acids may help to reduce production of inflammatory compounds, reducing oxidative stress to the kidneys and slowing the progression of chronic kidney disease. Diets containing omega-3s have been recommended for dogs with CKD.
*In a 90-day randomized double-blinded controlled study of pet dogs with lameness from osteoarthritis, dietary supplementation with fish oil significantly improved the dogs’ ability to walk and bear weight.
*A 2023 study found that fish oil supplementation enhanced learning ability in puppies.
Does that mean that all dogs should receive fish oil supplements? Not necessarily. Dogs in good health with great coats are probably doing fine without fish oil. Here’s what else to consider before adding fish oil to your dog’s daily routine.
Is Fish Oil Right for Your Dog?
While fish oils usually do not have significant side effects, some dogs are sensitive to fish oil, especially in high amounts. Dogs who respond to fish oil with vomiting or diarrhea may be in this category. Pregnant or nursing dogs may also not respond well to fish oil. To reduce the risk of gastrointestinal upset, start with a low dose and gradually increase it.
If your dog takes prescription, herbal, or over-the-counter medications or has a blood-clotting disorder, diabetes, or a history of pancreatitis, talk to your veterinarian first before adding fish oil to your dog’s diet. Some medications or herbs may interact with fish oil in negative ways.
For dogs with health or skin conditions that could benefit from omega-3s, don’t double the amount. Too much of anything, no matter how natural or healthy, can cause side effects.
Some foods are already fortified with omega-3 fatty acids. If the label doesn’t indicate a guaranteed amount, contact the manufacturer and ask about the percentage of fatty acids in the food. The answer can help you and your veterinarian determine whether it’s appropriate to supplement with additional omega-3 fatty acids.
The Best Fish Oil for Dogs
Whole Dog Journal is reader-supported. If you purchase through links on our site we may earn a commission. Whole Dog Journal does not accept money for its food and product reviews.
Not all fish oils are created equal. The U. S. Food & Drug Administration does not regulate pet supplements such as fish oil. Consider these factors when deciding which one to purchase for your dog:
- The label should specify the amounts of EPA and DHA.
- The manufacturer should use third-party testing to evaluate purity and freshness and can provide a certificate of analysis on request.
- The oil should be made from fish such as anchovies, cod, mackerel, pollock, sardines, and wild-caught salmon, which are low in heavy metals and other impurities.
- The product should be formulated for pets so you know your dog isn’t receiving an excessive amount and that it doesn’t contain ingredients that could be harmful to pets.
As stated above, the best fish oil for dogs should contain the omega-3s DHA and EPA. Colorado State University Veterinary Teaching Hospital recommends choosing a product evaluated for purity and freshness via third-party testing. Some products are audited by the National Animal Supplement Council (NASC), meaning they must meet certain quality-control criteria. We like the following products:
- Alaska Naturals Wild Alaskan Salmon Fish Oil for Dogs: NASC-audited; third-party tested for quality.
- Grizzly Wild Alaskan Salmon Plus: NASC-audited.
- Iceland Pure Pet Products Unscented Pharmaceutical Grade Sardine & Anchovy Oil Liquid Dog & Cat Supplement: Samples tested regularly for purity by licensed, third-party testing companies.
- Nordic Naturals Omega-3 Pet Soft Gels: Made with wild anchovy and sardine oil. Third-party tested. Also available as a liquid.
- Pet Honesty Wild Alaskan Salmon Oil: NASC-audited.
Before giving fish oil to your dog, smell or taste the oil to make sure it isn’t rancid. You may think your dog won’t care—he may scarf up worse things than old fish oil—but he won’t see benefits from it and may experience one of the side effects you’re trying to prevent: inflammation.
When it comes to administering fish oil, some dogs will swallow a gel capsule whole while others may prefer to take their fish oil in liquid form, pumped onto their food from a dispenser or squeezed onto food from a punctured capsule.
