Anyone with a fish tank often observes the pet cat, tail twitching, stalking the fish.
Cats are obligate carnivores meaning they must eat primarily meat as their main source of food. They may also eat a small amount of vegetables, fruits and grains. The intestines of cats are shorter than ours and they cannot fully digest plant materials.
Cats need taurine found in high concentration in the heart and liver of animals as well as in the muscles. Fish also contain taurine. Taurine is an amino acid that regulates heart rhythm, reproduction, digestion and vision. Most mammals manufacture taurine from other amino acids but cats can’t and must have their diet supplemented.
Fish is another source of protein for cats. But there can be too much of a good thing. Fish can contain high levels of mercury and other toxins. Feeding your cat a diet high in fish is linked to Urinary Tract Infections (UTIs) and hyperthyroidism. Some cats can even be allergic to fish. It’s best to limit fish meals to no more than twice weekly.
Cats can be picky eaters. You may have to experiment until you find a food your cat likes.
We had 3 cats, all with individual tastes. One would eat liver while the others turned their noses up at it. They all liked chicken and fish was a once a week treat.