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From Anxiety to Arthritis, This Fast-Growing Pet Supplement Is a Godsend

Analysis by Dr. Karen Shaw Becker

fish oil for pets

Story at-a-glance -

  • One of the fastest-growing dietary supplements for pets is fish oil — a rich source of omega-3 essential fatty acids
  • Omega-3 fats have a wide-ranging and potent effect on the health of dogs and cats
  • Developing puppies, anxious dogs, and pets with arthritis, heart disease, chronic kidney disease or inflammatory skin disease are examples of animals who can benefit from omega-3 supplementation
  • Fish body oils such as krill oil are among the cleanest sources of omega-3 fats for pets

Every day, more and more pet parents are realizing the tremendous benefits of nutritional and issue-targeted dietary supplements. As Bill Bookout, president and founding member of the National Animal Supplement Council (NASC) told Veterinary Practice News a few years ago:

"There aren't any magic bullets out there, but I think supplements are becoming more and more recognized and substantiated as a valuable component of a comprehensive care program where we either try to maintain general health and wellness, or manage health as a result of the aging process or some health challenge."1

One of the fastest growing categories of pet supplements is fish oil aka fish body oil, a rich source of essential fatty acids (EFAs), more commonly known as omega-6 and omega-3 fats. While dogs and cats need a balance of both for good health, omega-3s are the superstars in terms of the significant health benefits they offer.

Omega-3 fatty acids include alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaneoic acid (EPA), which play a role in your pet's overall health in many ways, including:

  • Regulating blood-clotting activity
  • Aiding proper development of the retina and visual cortex
  • Alleviating the harmful effects of allergies and other conditions that result from an over-reactive immune system response
  • Slowing the growth of common yeast infections
  • Slowing the development and spread of certain types of cancer

Along with these benefits, multiple clinical studies show that omega-3s are helpful in the prevention and treatment of several conditions involving the cardiovascular system, cognitive function, neurological health, inflammatory skin disease, kidney disease and osteoarthritis.

Benefits of DHA Supplementation in Growing Dogs

A study published in 2012 in the Journal of the American Veterinary Medical Association indicates that feeding newly weaned puppies foods high in DHA has wide-ranging health benefits.2 The goal of the study was to evaluate the effect of food with added DHA from fish oil on the cognitive, memory, psychomotor, immunologic, retinal function and other developmental measures in 48 healthy, newly weaned 8-week-old Beagle puppies.

The researchers observed that the puppies fed diets containing the highest levels of DHA had significantly better results than the other groups in reversal learning tasks, visual contrast discrimination and early psychomotor performance. They also had significantly higher rabies antibody titers one and two weeks after vaccination, and an improved ability to see in low-light or dark conditions.

Increased Consumption of EPA Calms Anxious Dogs

If your dog suffers from anxiety, she may benefit from supplementation with a high-quality source of omega-3 fats, due to their ability to modulate neurotransmitters and neuroplasticity in the brain.

In 2008, researchers compared the omega-3 fat EPA against the antidepressant drug fluoxetine (Prozac) and discovered EPA was just as effective as the drug in relieving symptoms of depression in humans, and the same may be true for dogs.3 Subsequent research involving 24 dogs found increased intake of omega-3 fats had a calming effect on anxious dogs and led to improvements in behavior.4

EPA and DHA Improves Symptoms in Arthritic Cats and Dogs

A 2013 study conducted in the Netherlands suggests that cats with naturally occurring osteoarthritis show symptom improvement when their diets are supplemented with omega-3 fatty acids.5 Sixteen arthritic cats were involved in the 10-week study. Some of the kitties received a fish oil supplement containing both EPA and DHA; others received a corn oil supplement with no EPA or DHA.

According to their owners, the cats receiving fish oil had less stiffness, higher activity levels, more stair climbing, higher jumping ability and more interaction with family members than the cats who received corn oil.

A Canadian study published around the same time indicates that omega-3s are equally beneficial for dogs with naturally occurring OA.6 The dogs were fed a diet containing high levels of omega-3 fatty acids from fish, and showed significant improvement in locomotor disability and performance of daily activities.

In another study, cats with degenerative joint disease (DJD) fed a diet high in EPA and DHA, plus green-lipped mussel extract and glucosamine chondroitin sulfate, showed improved measurements of mobility.7

Omega-3 Fats Improve Cardiac Function in Dogs With Heart Disease

In a 1998 study of dogs with dilated cardiomyopathy (DCM), omega-3 supplementation reduced production of inflammatory cytokines (interleukin-1 and prostaglandin-E2), and also reduced muscle loss compared with a placebo.8 The decreased production of inflammatory cytokines is also thought to improve appetites in animals with heart failure.

In a retrospective study of 108 dogs with DCM or chronic valvular disease, results showed improved survival rates with omega-3 fatty acid supplementation.9 In addition to improved heart function (including reduced heart rate and blood pressure), omega-3 supplementation also reduced inflammation and improved the dogs' appetite and maintenance of lean body mass.

EFAs Significantly Improve Symptoms in Pets With Itchy, Inflamed Skin

In a 1994 study of 16 dogs given omega-3 fatty acids that included high levels of EPA showed improvement in itchiness, self-trauma, coat character and hair loss compared with administration of ALA alone.10 The dogs in the study had symptoms of idiopathic pruritus (unexplained itchy skin), confirmed atopy (inflamed skin due to allergies) and/or flea allergy.

In 2014, a study conducted in Munich, Germany evaluated a spot-on formulation of essential fatty acids and essential oils on 48 dogs with canine atopic dermatitis.11 The results showed that individual improvements in lesion and itchiness scores were significantly higher for dogs that received the EFAs and essential oils versus the control group, and more of those dogs also showed a 50 percent or greater improvement in itchiness.

Omega-3s Improve Survival Times for Pets With Chronic Kidney Disease

In a study of dogs with experimentally induced chronic kidney disease (CKD), researchers demonstrated that supplementation with omega-6 fatty acids accelerates the decline of kidney function, while omega-3s do the opposite.12

A retrospective study of 146 cats with chronic kidney disease showed a survival time of 16 months for those on a diet supplemented with EPA, compared with seven months for the control group. The cats receiving the highest amounts of dietary EPA had the longest survival times.13

Ensuring Your Pet's Diet Is Rich in Omega-3s

Processed pet food is manufactured at very high temperatures, and since omega-3 fatty acids are sensitive to heat and light, they are inert by the time they are packaged. Even if you feed your pet homemade raw meals, if you're not following a balanced recipe that calls for extra essential fatty acids (omega-3s from seafood), your dog's or cat's diet is probably unbalanced for fatty acids.

Not only are omega-3s important, so is the dietary ratio of omega-3s to omega-6s. Because the average pet diet is heavy in omega-6s, supplementing with additional omega-6s in the form of corn, olive, safflower or even flax oil (which contains some vegetable sources of omega-3s, but also omega-6s) can create an imbalance that can lead to health problems.

Krill oil is the supplement I recommend to ensure your dog or cat is getting enough omega-3 fats in his diet. Dogs and cats can't efficiently convert plant sources of omega-3 fatty acids (from flaxseed oil, for example) into appropriate amounts of DHA and EPA, so the best option is to provide one in its already-bioavailable form from marine oils.

As I mentioned, omega-3s are very sensitive to oxygen and can become rancid quickly, so I prefer oils either dispensed from an airless pump or in capsules that can be cut and squeezed onto food just prior to feeding. With "pour on" oils there is a far greater risk of oxidation over time, so if you do purchase a bottle, make sure to refrigerate it after opening and try to use it up within 30 days.

Try to ensure your fish oil is sustainably harvested, or MSC-approved, and comes from nontoxic fish (the smaller the better, hence my recommendation of krill oil).

Cod liver oil and other fish liver oils, while rich in omega-3 fatty acids, are also very high in vitamins A and D. Since dogs and cats eating commercial pet foods are already getting adequate amounts of these fat soluble vitamins, too much can result in toxicosis or abnormal calcium and phosphorus levels that can cause mineralization and calcification of vital tissue and organs, as well as urinary stones. That's why fish body oils without vitamin D are preferred for pets.

It's important to seek the advice of an integrative veterinarian to determine how to best supplement your dog's or cat's diet with the fatty acids he needs for good health and to treat any specific health conditions he may have.