The Facts About Fish Oil Supplements

It seems there is an abundance of information about the health benefits of fish oil and many times when I suggest using it for a patient I often hear from the client “Yes, I take fish oil too for my heart or my arthritis.” Fish oil is a well accepted nutritional supplement that most veterinarians are recommending for a broad range of patients.

I think an important point that is being missed by many who take fish oil is that quality matters. It’s really all about the fishy burps. If you’ve had one you know what I mean! So why do fishy burps occur with some supplements and not when we eat fish? The answer requires us to freshen up on a little basic biochemistry. Fish oil is composed of primarily two long-chain unsaturated fatty acids, EPA and DHA. Unsaturated fatty acids are highly susceptible to oxidation in the presence of oxygen which causes the oil to become rancid. Oxidized fish oil (or any unsaturated fatty acid oil for that matter) has an offensive fishy odor and taste. When we eat fish we don’t get the fishy burps because it has been refrigerated or frozen to reduce oxidation and spoilage, therefore the oils present in the fish are also fresh. The best way to tell if a fish oil is fresh is to taste it. That’s right; bite the gel capsule in half and taste the oil. The freshest fish, oil, and/or supplement will have the best health benefits. The following is some basic information regarding fish oil supplementation for companion animals. For specific doses please consult a veterinarian.

Proven Benefits:

• Improved skin and coat


• Reduced inflammation due to arthritis, allergies, and inflammatory bowel disease


• Regulation of the immune system. This can work in both directions: boost immunity if low and suppress immune system if excessive.


• Improved brain function in older dogs with senility. 


• Enhanced brain and mental development in puppies and kittens.


• Lowering blood pressure (important in kidney, heart, and endocrine diseases).


• Lowering triglycerides (important in endocrine diseases and in familial affected Miniature Schnauzers).


• Promote weight loss in overweight dogs.


• Provides support in pets with cancer. 


• Provides support in pets undergoing cancer treatments such as chemotherapy and radiation.

Cautions:

• Fish oil is easily oxidized by exposure to oxygen, heat and light. When fish oil becomes oxidized it will develop a strong fishy and rancid odor. Rancid fish oil is not absorbed and contributes to fishy burps and fishy odor to skin and breath. To protect fish oil, store capsules or oil in the refrigerator and only buy a quantity you will use within 3 months maximum. If you notice an “off” odor the oil should be discarded.


• High doses of fish oil can interfere with platelet function and can create bleeding issues. It may be advisable to discontinue a fish oil supplement prior to surgery or dental procedures, check with your veterinarian. 


• Too much fish oil may add excess calories or increase inflammation rather than reduce inflammation in some situations.

Not all products are created equal:

• Pharmaceutical grade fish oil is molecularly distilled to remove toxins and impurities. The best companies producing fish oil are testing their finished products for the bad stuff such as PCBs, dioxins and furans, bacteria such as Salmonella and E. coli, yeast and mold, heavy metals (cadmium, arsenic, lead, mercury), and radiation.  These companies are also diligently measuring levels of oxidation which determines freshness and fatty acid ratios which determine the potency. Thorough testing increases the cost of producing a high quality product. For this reason the best oils from a standpoint of purity, potency, and freshness will not be the least expensive but will be more effective for your pet’s health and wellness. 
  

Sources of Omega 3:

• Cold water fish are the best sources of omega 3 fatty acids. These fish include sardines, cod, and anchovies. Recently krill (shrimp-like crustaceans, sole food source for whales) have been harvested to create fish oil supplements. Krill are an excellent source of omega 3 fatty acids, but these fishing practices are not environmentally sustainable and I recommend avoiding krill oil for the health of our planet.


• Omega 3 fatty acids are also present in flax seed and several other food sources. It’s important to note that dogs and cats are not able to convert large amounts of ALA in plants to EPA and DHA. Inefficient conversion of flax oil to the useable forms of EPA and DHA is why I don’t recommend flax seed oil as a sole source of omega 3 supplementation.
  


• Many pet foods have added Omega 3 to the diets. If in the form of fish oil, the oil would be subject to rapid oxidation once the bag of kibble is opened, therefore smaller bags of food would be preferred to optimize the freshness of the added fish oils. There is also no way to know if the added fish oils are high quality or what testing is done prior to adding to the food. Flax seed oil added to food seems of little benefit to the pet since dogs and cats cannot convert it to useable forms. 


• Canned fish can be a good source of fish oil for dogs and cats. For example: one ounce of canned fish with bones (sardines, mackerel, pink salmon) averages 300 mg EPA and DHA. Cats especially may prefer canned fish rather than adding a fish oil supplement to their food. Make sure you select a fish canned in water not oil or any special sauce.


• There are many different brands of fish oil supplements available for people and animals. For myself and my own pets I have used products made by Nordic Naturals, Thorne Research, and Nutramax Laboratories. 


• Cod liver oil is another excellent source of fish oil that also contains Vitamins A and D. Cod liver oil would be useful for pets eating a home-cooked diet. For specific doses, please consult your veterinarian.