The benefits of flaxseed and other oils

In feline and canine diets, fats and fatty acids provide energy. They also enable the absorption of fat-soluble vitamins, regulate inflammatory processes, help form cell membranes and promote skin function.

Extra fatty acids

Neither cats nor dogs can produce or synthesize unsaturated omega-3 and omega-6 fatty acids in sufficient amounts. So exogenous linoleic, alpha- linolenic, arachidonic, eicosapentaenoic and docosahexaenoic fatty acids must be provided in the right proportion in food.

National Research Council (NRC) and Association of American Feed Control Officials (AAFCO) norms define minimum fatty acid requirements, depending on species and age (see graph).

Sources and concerns

Animal fats are the source of AA, while fish oil contains EPA+DHA, and vegetable oils provide LA and ALA. Many fats, however, are a source of highly concentrated energy that may cause overweight and obesity. Too much fat can also lead to diarrhea or pancreas inflammation. So the concentration of polyunsaturated fatty acids should underlie the choice of dietary oil.

Compared to other vegetable oils, cold-pressed flaxseed oil, also known as linseed oil, has a very high content of alpha-linolenic acid – more than 50%. As little as 0.5 g of flaxseed oil fully covers the requirement of a 30 kg adult dog while containing just 4.5 kcal.

Supplementation

Cold-pressed flaxseed oil also contains vitamin E in the form of β- and γ-tocopherols, natural antioxidants regarded as the most potent free radical removers among vitamin E isomers.

Additional supplementation with flaxseed oil can support pet skin and coat health, improve the functioning of the digestive tract and immune system, and regulate inflammatory processes.

With just 14% of the required LA in flaxseed oil, a balanced diet should also include other vegetable oils. For instance, evening primrose, grapeseed and walnut oils each contain more than 50% of the required LA. Walnut oil has the best ratio of omega-6 to omega-3 fatty acids (5:1) and, like flaxseed, is a good source of vitamin E.

Nut oils (almond oil, peanut oil, hazelnut oil) mostly contain oleic acid, which is part of the omega-9 family and not essential in a pet’s diet. For other nutrients, nut fat can be used in the form of cold-pressed oil or as ground nuts. Regular nut flour contains more than 50% fat, a substantial amount of protein (15%) and dietary fiber. Ground flaxseed has a high fat (42%) and fiber (27%) content.

Safety

Applying flaxseed in a pet’s diet may seem controversial as it contains cyanogenic glycosides – bioactive plant products derived from amino acids. The cyanogenic precursor content in ground flaxseeds varies between 80 and 300 mg/kg. 1 gram of flaxseed per 1 kg of body weight is regarded as safe for dogs, but the recommended dosage for pets is much lower. Even below the toxic threshold, a higher amount of flaxseed frequently causes digestive tract disorders (diarrhea and bloating), which discourages owners from administering amounts that could result in cyanogenic glycoside poisoning.

Nut oils are considered safe, but feeding ground nuts to pets requires caution because of possible contamination with mycotoxins. Dogs and cats should not eat macadamia or black walnuts, as these may cause weakness, mild central nervous system depression, vomiting or hyperthermia.