Is Fish Oil Healthy For Dogs?

If you ask a veterinarian about the supplement they most commonly recommend for their canine patients, they would probably say fish oil. This dietary supplement is a safe addition to most dogs’ diets and has a wide range of benefits from alleviating itchy skin to helping manage joint discomfort from arthritis.


The Benefits of Fish Oil for Dogs

Vets typically recommend fish oil supplements because your dog’s coat is dry. Humans mistakenly view fat as the most harmful part of a diet, but this definitely isn’t true in regards to canine nutrition. A very low-fat diet for dogs starts to affect their coats, resulting in dull, coarse fur. It also increases shedding. There are a few medical conditions (hypothyroidism or Cushing’s disease, for example) that negatively affect the coat, so ensure your dog gets examined by their vet before you assume fish oil will fix their coat. If it is just a deficiency in omega-3 fatty acids, a daily supplement should help your dog regain their shiny, soft coat.

Omega-3 fatty acids have been shown to reduce inflammation in the body, especially if it’s a result of osteoarthritis. This doesn’t mean fish oil is a suitable replacement for a non-steroidal anti-inflammatory for arthritis, but a decent level of omega-3s will help alleviate inflammation in the joints. If your dog has been diagnosed with arthritis, administering fish oil is an excellent way to reduce joint inflammation. Dogs with chronic allergies that create itchy skin and dandruff benefit from fish oil, too, because allergies are a result of inflammation.

Fish are naturally rich in DHA, a type of omega-3 fatty acid. DHA is important in the brain and eye development of puppies, and some nutritionists recommend giving pregnant or nursing dogs fish oil. This allows the puppies to get the needed DHA to promote great brain growth and vision. It can also be helpful for senior dogs whose vision and cognitive function are starting to decline.

Some studies have indicated omega-3 fatty acids slow the growth of cancer. While the exact mechanism is unknown and more study is needed before this is considered an effective treatment, some veterinary specialists will recommend fish oil for cancer patients.

How Much Fish Oil Should I Give My Dog?

Fish oil made specifically for dogs comes in capsule or liquid form. Your vet may carry a brand or two, or they can order one for you. You can safely give your dog fish oil made for humans; just ensure the supplement contains only fish oil. Run the other inactive ingredients by your vet if you aren’t sure whether that particular brand is safe or not.

The dosage of 20mg/lb is only a guideline. Your vet is the only one who can give you the exact dosage. Remember your dog’s weight isn’t the only factor in dosage calculation. It varies depending on what you’re trying to treat with the fish oil, as well as the condition’s severity. What kind of dog food you feed is a consideration, too. Some commercial dog foods have omega-3 fatty acids added which means your dog could need less in terms of supplementation. Finally, higher quality fish oils differ in concentration, altering the appropriate dosage.

Fish Oil Side Effects

Too much fish oil typically results in stomach upset. If your dog has a history of GI problems or a sensitive stomach, you have to introduce fish oil slowly or you’re going to give your dog diarrhea. Omega-3 fatty acids have been shown to slow blood clotting, meaning dogs on blood-thinning medications or with a history of blood disorders shouldn’t take fish oil.

If your dog is taking an anti-inflammatory medication already, it’s important you consult with your vet before starting fish oil therapy. Even though it’s natural, there’s still the potential for medication reactions. Side effects created by a dosage that’s too high include fishy breath, greasy stools, diarrhea, and weight gain. Any time you notice anything new or unusual in your dog, run it by your vet.


Fish oil is safe for dogs, but it isn’t necessary if you buy a high-quality dog food. Remember that even the best intentions can have negative effects on your dog’s health. Always consult with your veterinarian before you decide to add anything to their diet. Nutrition is incredibly important in regards to having a healthy dog, so don’t make any nutritional decisions without your vet’s input.