Omega-3 fatty acids are a type of polyunsaturated fatty acid (PUFA) named for their chemical structure. The omega-3 fatty acids alpha linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are considered essential during growth for puppies and kittens, “essential” meaning the body cannot make its own ALA, EPA, and DHA in sufficient amounts for proper growth and development. Further, adult dogs and cats have a very poor conversion of ALA to EPA and DHA. As a result, they must be provided by the diet.
Sources of Omega-3s for Pets
Where do omega-3 fatty acids come from? Sources of omega-3s include fish and other marine species such as krill, calamari, green lipped mussel, and algae. The fish species used to produce omega-3 fish oils do not produce them directly; rather, they accumulate the omega-3s from the algae, krill, and other prey they consume. The active omega-3s in these marine sources are EPA and docosahexaenoic DHA. Some nuts and seeds also contain omega-3 fatty acids; however, they have a higher content of ALA. In humans, dogs, cats, and horses, only about ten percent of ALA can be converted to the more active, desirable EPA and DHA; therefore, using marine sources is preferred.1-4
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Omega-3 Mechanism of Action
After digestion and absorption, omega-3 fatty acids will incorporate into cell membranes of body tissues and organ systems, altering the building blocks available for many metabolic pathways. The results of these changes are molecules that are less inflammatory or that may be described as “inflammation resolving.”5
Omega-3 Supplements for Dogs and Cats
Omega-3 fatty acids are positively associated with addressing numerous health conditions in pets, including:
- Joint disease: osteoarthritis6,7
- Dermatitis: allergy and allergic tendency, itchy skin and poor coat quality, nail and claw disorders8,9
- Renal or urinary diseases: chronic kidney disease, proteinuria, FLUTD10
- Cardiac disease: arrythmia, cachexia2, 11-12
- Gastrointestinal disorders: IBD, pancreatitis5,13
- Lipid disorders: hyperlipidemia5, 14-15
- Cancer (5, 16)
- Cognitive function, neurologic health, behavior/aggression5, 17-18
While optimal dosing has not been determined for pets, general guidelines have been offered from a compilation of studies for most health conditions. Safe upper limits have also been established as higher dosing may infrequently cause adverse effects. Veterinary input is recommended to determine the optimal omega-3 fatty acid supplementation plan for your pet and his/her unique needs.
Potential side effects or adverse effects of omega-3s for pets
Supplementation is considered very safe when given at appropriate levels and with veterinary supervision. Some potential adverse effects have been noted at higher doses in dogs and cats including altered platelet function, delayed wound epithelialization, altered immune function, adverse gastrointestinal effects or rarely weight gain.19
Veterinary guidance is essential to ensure that dosing is appropriate and to avoid adverse effects. This is important as many pets can have multiple disease conditions or are prescribed medications or other supplements. Experts recommend that pet owners always seek veterinary guidance when using supplements for a dog or cat.
Omega-3s and Joint Health
Perhaps the most common use of omega-3 fatty acids is for the management of joint health. Studies evaluating inflammatory mediators (thromboxane, leukotriene, and matrix metalloproteinase) within the joint fluid documented a reduction of these inflammatory mediators with omega-3 supplementation.20-21 Improvements in mobility and a reduction in lameness was reported in two studies in dogs fed a therapeutic diet supplemented with omega-3 fatty acids.22-23 Improvements in mobility (i.e. increased activity and jumping) with a reduction in lameness and stiffness was documented in cats fed a therapeutic diet containing omega-3 fatty acids.24
Omega-3s and Skin
Pruritis (itchy skin) is a common and frustrating problem experienced by many dogs and cats. Causes may include allergies (environmental, food, or fleas), skin infections, parasites, or skin and coat barrier defects. In one study of dogs with environmental or flea allergies, supplementation with a fish oil containing EPA and DHA reduced pruritis after six weeks.25 Dogs with less advanced allergies responded better than those with more chronic skin conditions. Fewer studies are available in cats; however, one study reported a greater reduction in skin inflammatory mediators (leukotrienes) for the cats supplemented with fish oil as compared to cats supplemented with flaxseed oil, which is high in ALA.26-27 Some of the veterinary therapeutic diets used to manage allergies contain omega-3 fatty acids; however, inclusion amounts vary and supplementation may still be needed for optimal dosing.
Omega-3 and Kidney Disease
Supplementation of omega-3 fatty acids may benefit dogs and cats with chronic kidney disease by reducing protein loss in the urine (proteinuria), reducing hypertension at the level of the kidney, and decreasing inflammatory changes within renal tissues.28-30 Many renal therapeutic diets include significant amounts of the omega-3 fatty acids EPA and DHA. These benefits may slow the progression of chronic kidney disease and extend lifespan.
Other Conditions Managed by Omega-3 Supplementation
Lipid disorders in dogs can be managed with a very low-fat diet, but this may not result in complete resolution or normalization of blood lipid levels. Omega-3 fatty acid supplementation have been recommended as an adjunctive treatment.14 Emerging areas for omega-3 supplementation include gastrointestinal disorders, cancer management, and neurocognitive health including behavior management.13, 18, 31-32
Diseases of the gastrointestinal tract frequently involve inflammation within tissues that in theory may be modified by omega-3 supplementation and result in improvement in symptoms. While studies in dogs are limited, a beneficial role for omega-3 fatty acids has been described in humans for colon, breast, prostate and other types of cancers.33-34 One study evaluated use of a diet supplemented with fish oil and other nutrients for dogs with lymphoma and receiving chemotherapy. The study reported elevated serum concentrations of DHA and EPA, improved glycemic responses, and a longer disease-free interval and survival time.16, 31
Omega-3 fatty acid supplementation also has known benefits for dogs with cognitive decline with aging and a reduction in seizure frequency when used in combination with anticonvulsants for dogs with epilepsy.35 Humans and dogs with behavioral alterations including aggression can have lower plasma DHA concentrations, suggesting that supplementation may be beneficial in these patients.17
Food and Omega-3s for Pets
Only a minimal requirement has been set by the Association of the American Feed Control Officials (AAFCO) for DHA content in pet foods for growth (0.08 percent ALA and 0.05 percent EPA and DHA, Dry Matter Basis) and for the ratio of EPA to DHA to total PUFAs in adult maintenance diets (maximum 30:1). This means that typical over the counter pet foods have only minimal amounts of EPA and DHA. Veterinary therapeutic diets for specific disease conditions are available and offer higher levels of omega-3s for pets. These veterinary therapeutic diets should be evaluated for type and amount of omega-3 included (ALA, EPA, and/or DHA) to determine its appropriateness for disease management.
As each patient is a unique individual and may have a combination of concerns, identifying a specific range of omega-3 intake for each dog or cat is best. This might include a combination of a therapeutic diet and a specific supplementation dose. Monitoring for adverse effects is very important. Experts recommend considering the combination of all supplements and/or medications being given and the potential for interactions. Dosing can be modified according to each pet’s tolerance and individual concerns. This plan will safely achieve maximal benefits of omega-3s for pets and support their health.