Fish Oil Dosage for Cats Calculator

Fish oil is dosed for its long-chain omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, not for the total volume of oil, so a label claiming 1000 mg of fish oil may deliver anywhere from about 120 to 600 mg of combined EPA and DHA. These fatty acids are incorporated into cell membrane phospholipids, where they compete with arachidonic acid as substrate for cyclooxygenase and lipoxygenase, shifting eicosanoid production toward the less inflammatory three-series prostaglandins and five-series leukotrienes and toward resolvins that actively terminate inflammation. That mechanism underlies their use in cats for pruritic skin disease, osteoarthritis, chronic kidney disease and cardiac support. Maintenance doses cited for general coat and skin condition are modest, in the region of 20 mg EPA per kilogram daily, while therapeutic anti-inflammatory targets are commonly two to three times higher. Cats cannot substitute plant sources. Feline delta-6 desaturase activity is low, so alpha-linolenic acid from flaxseed converts poorly to EPA and DHA, and cats likewise depend on preformed arachidonic acid from animal tissue. Cod liver oil is a poor choice because its vitamin A and vitamin D content can reach toxic levels with chronic use, and hypervitaminosis A in cats produces painful proliferative bone lesions around the cervical spine. Excess omega-3 carries its own costs, including diarrhea, delayed platelet aggregation, oxidative stress that raises vitamin E requirements, and a meaningful calorie load in a small animal, which is why the National Research Council defined a safe upper limit rather than an open-ended recommendation. Oils oxidise readily; refrigerate them and discard anything that smells rancid.

Interest in long-chain omega-3 fatty acids grew out of epidemiology rather than pharmacology. In the 1970s the Danish investigators Hans Olaf Bang and Jorn Dyerberg studied Greenland Inuit populations whose heavily marine diet coincided with unusual plasma lipid profiles, and their work turned EPA and DHA into a research field. Through the 1980s and 1990s the anti-inflammatory mechanism was worked out in terms of competition with arachidonic acid, and from around 2000 Charles Serhan and colleagues at Harvard identified resolvins and protectins, specialised mediators derived from EPA and DHA that actively switch inflammation off rather than merely dampening its initiation. Veterinary uptake followed. Dermatology trials in dogs and cats through the 1990s tested omega-3 supplementation for allergic skin disease with mixed but encouraging results, and canine osteoarthritis studies in the late 2000s reported measurable improvements in weight bearing on high omega-3 diets. In feline medicine the strongest interest has been in chronic kidney disease, where therapeutic renal diets containing fish oil are associated with longer survival than maintenance diets, although diet trials cannot isolate the omega-3 contribution from phosphorus restriction and the other formulation changes made at the same time. The National Research Council addressed these fatty acids directly in its 2006 Nutrient Requirements of Dogs and Cats, setting recommended intakes and a safe upper limit for combined EPA and DHA, which remains the reference point for supplement dosing today.