Glossary

Arachidonic acid

An omega-6 fatty acid that cats cannot make from plant oils in sufficient amounts and so need ready-made from animal fat.

Also called: ARA, omega-6 fatty acid, essential fatty acid

Arachidonic acid, often shortened to ARA, is a long-chain omega-6 fatty acid. Most mammals can build it from linoleic acid, a fatty acid found in plant oils. Cats have very low activity of the enzyme that does the conversion, so they cannot rely on it and must get arachidonic acid itself from animal fat, such as the fat in poultry, pork or fish and eggs. It is another reason cats count as obligate carnivore animals.

The body uses arachidonic acid in cell membranes, skin health, blood clotting and the inflammatory response, and it is needed for reproduction. A cat lacking it can have a poor coat, skin trouble, clotting problems and poor breeding performance.

Commercial foods labelled complete and balanced contain enough to meet nutrient standards, so owners seldom need to think about it. The risk comes with home-prepared diets built around lean meat or plant oils, which may fall short. Do not add supplements or oils on your own, because too much of some fats can cause problems. If you want to prepare food at home, ask your vet to refer you to a board-certified veterinary nutritionist who can design a recipe.

Last reviewed November 7, 2026

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Related terms

Obligate carnivore An animal that must eat animal tissue to get nutrients its body cannot make for itself, as domestic cats must. Taurine An amino acid cats cannot make in enough quantity and must get from food, essential for heart muscle, eyesight and reproduction. Complete and balanced A pet-food label claim that a food supplies all the nutrients a cat needs at a stated life stage, when used as the only diet. Raw diet A diet of uncooked meat, organs and bones, whether home-made or bought, which carries infection and nutrition risks that vets warn about. Wet food Cat food sold in cans, pouches or trays, containing roughly 70 to 80 percent water, which helps a cat get more fluid.