We all know about the benefits of fish oil for us and for our dogs. Most dogs eat a processed diet, or a diet consisting mainly of factory farmed meats, and this causes an imbalance of fats, with an over-abundance of omega-6 and too little omega-3. This imbalance can lead to inflammatory disease such as allergies and arthritis.

Omega-3 is present in many plant sources and, for our carnivorous friends, in oily fish. So we use fish oil to correct the imbalance in the diet. Problem solved, right? Not exactly; there are some hooks you need to first be aware of.

The Problem With Fish Oil

DHA and EPA, the oils that we need in fish oils, are highly unsaturated. The less saturated an oil is, the more unstable it is and the more quickly it oxidizes. In fact, this is why fish goes bad so quickly.

According to research, oxidized fish oil isn’t merely useless. In humans, rancid fish oil is associated with health risks such as atherosclerosis and thrombosis (hardening of the arteries and increased blood clotting), which is ironically why most people take fish oil.

Dr Michael R Meades warns “Lipid peroxides can (and do) start free radical cascades that can damage fatty cellular membranes. At the very least lipid peroxides consume the body’s stores of vitamin E and other antioxidants to neutralize them, leaving the body short of many of its natural defenses.”

Just how many fish oils on the market are rancid? Researchers at New Zealand’s Crop and Food Institute tested capsules from a variety of brands from around the world and found that the majority of the capsules tested had already begun to oxidize.

How To Protect Your Dog’s Fish Oil From Oxidation

Although most fish oils will already be oxidized before you purchase them, there are a few steps you can take at home to extend their freshness. First, purchase the highest quality fish oils you can. Most fish oil manufacturers will purify the fish oil, removing any oxidized substances. Adding the antioxidant vitamin E after purification will help prevent further oxidation.

Second, Dr Meades recommends placing your fish oil liquid or capsules in glass bottles. Glass is impervious to air, while plastic isn’t. Finally, placing your fish oil in the fridge, just like you would fresh fish, will extend its life and slow the oxidation process.

Like everything else in life, there are both risks and benefits to fish oils. Taking care of your fish oil and choosing your manufacturer carefully will go a long way to minimizing the risk of oxidation.

Note: Phytoplankton is considered the “king of antioxidants”. Find out why you should add phytoplankton to your dog’s diet here.