Giving your dog plenty of this might help prevent lymphoma

Analysis by Dr. Karen Shaw Becker

omega-3 canine lymphoma

Story at-a-glance -

  • A recent study of golden retrievers with T-zone lymphoma suggests that dogs eating diets rich in omega-3 essential fatty acids may be less likely to develop the disease
  • Omega-3s are simply the superstars of essential fatty acids in terms of the significant health benefits they offer pets
  • Studies show omega-3s are beneficial for the healthy development of puppies and for dogs with anxiety, arthritis, heart disease, chronic kidney disease and itchy, inflamed skin
  • The best sources of omega-3s are fish body oils

Canine T-zone lymphoma (TZL) is a slowly progressive form of cancer most often seen in older dogs, comprising about 12% of canine lymphoma cases. This type of lymphoma is far more prevalent in golden retrievers than any other breed, accounting for 40% of all cases.1

A team of researchers at Colorado State University's (CSU) College of Veterinary Medicine and Biomedical Sciences conducted a study to evaluate associations of genetics, environment, lifestyle and health history of T-zone lymphoma in Goldens. Their results were published recently in the Journal of Veterinary Internal Medicine.2

Study — Omega-3 fatty acids may provide protection against T-zone lymphoma in dogs

The dogs were recruited from Morris Animal Foundation's Canine Lifetime Health Project Registry. Many of the dogs were entered into the registry to be enrolled in the foundation's Golden Retriever Lifetime Study but were too old to participate. For the study, the researchers analyzed detailed health history questionnaires and blood or biological samples from more than 350 Goldens that were split into a group of dogs with TZL, and a control group of healthy dogs who were at least 9 years old.

The health history questionnaires covered topics such as the dogs' living situation, vaccination history and potential exposure to toxins. The researchers used blood samples to try to locate areas in the dogs' chromosomes associated with having or not having the disease. The study results indicate that dogs receiving omega-3 fatty acid supplements may be less likely to develop T-zone lymphoma. (Interestingly, dogs with hypothyroidism are also at decreased risk.)

"Although controlled prospective studies would be necessary to firmly establish protection by omega-3 fatty acids, our observations raise the possibility of a simple intervention that may help reduce the frequency of this disease," said Dr. Anne Avery, associate professor, department of Microbiology, Immunology and Pathology at Colorado State University.

"We were also a little surprised to discover that defective genes that lead to another, seemingly unrelated disorder — hypothyroidism — are more common in dogs that do not develop T-zone lymphoma."3

While the study focused on Goldens, Dr. Avery believes the underlying causes of TZL are shared across breeds. These findings support what Dr. Anna Hielm-Björkman and her Helsinki Vet School DogRisk project also discovered — dogs, regardless of breed that were supplemented with fish oil had less cancer than unsupplemented dogs.

Omega-3s — The superstars of essential fatty acids

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:

  • 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
  • Regulating blood-clotting activity
  • Aiding proper development of the retina and visual cortex
  • 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.

DHA is beneficial for puppies

A study published in 2012 indicates that feeding newly weaned puppies foods high in DHA has wide-ranging health benefits.4 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.

EPA calms anxious dogs

Dogs suffering with anxiety 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.5

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.6

EPA and DHA improve symptoms in arthritic dogs

A 2013 Canadian study indicates that omega-3s are beneficial for dogs with naturally occurring osteoarthritis.7 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.

Omega-3s 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.

Omega-3s improve chronic kidney disease survival times

In a study of dogs with 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.10

EPA significantly improves 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.11 The dogs in the study had symptoms of idiopathic pruritus (unexplained itchy skin), confirmed atopy (inflamed skin due to allergies) and/or flea allergy.

A 2014 study evaluated a spot-on formulation of essential fatty acids and essential oils on 48 dogs with canine atopic dermatitis. 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% or greater improvement in itchiness.12

The best sources of omega-3 fatty acids

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 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 pet is getting enough omega-3 fats in his diet. Dogs 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). Many people afraid to feed fish from the ocean find comfort in the third party-validated, toxin-free marine oils available in the market. Unlike fish, fish oils can be tested for purity and potency. If you have concerns about the quality of your fish oil, ask the manufacturer to provide you with third party testing results that demonstrates the product is toxin-free.

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 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 diet with the fatty acids he needs for good health and to treat any specific health conditions he may have.