Cats like fish because of its strong smell and protein, but fish alone isn’t a balanced diet for them.
Why
- Strong smell attracts cats.
- Protein and omega-3 fatty acids.
- Taste for umami.
Is it good
Fish can be part of a diet, but fish alone lacks taurine balance. Raw fish can cause thiamine deficiency.
Mercury
Tuna can contain mercury.
Feeding
Choose commercial cat food with fish as a flavor. Give cooked fish only occasionally.
Origin
Domestic cats were not adapted to fish. Their ancestors ate small rodents.
Biology of cats and fish
Cats are obligate carnivores and need taurine, arachidonic acid and preformed vitamin A from animal tissue. Fish provides protein and fat, with strong smell compounds like trimethylamine that attract cats. Cats evolved in arid regions and had limited fish exposure, so the fish preference is more cultural than genetic, shaped by humans feeding fish to pets.
- Fish-flavored cat food is among the most common varieties, with tuna and salmon leading.
- Raw fish contains thiaminase, an enzyme that destroys thiamine (vitamin B1) and can lead to neurologic signs if fed raw regularly.
- Tuna as a main diet can cause nutritional imbalance, and steatitis (yellow fat disease) from high unsaturated fat with low vitamin E.
- Fish can also trigger food allergies. Beef, dairy and fish are the top three cat food allergens, according to a 2016 review.
Mercury and portions
Large predatory fish such as tuna accumulate mercury, so tuna meant for people should be an occasional treat. Choose complete and balanced cat foods that meet AAFCO standards. Remove bones, cook fish without seasoning, and avoid onion or garlic. Feed treats within 10 percent of daily calories.
Biology
Cats are obligate carnivores and find strong smelling fish appealing. Fish is rich in protein, taurine and omega 3 fatty acids. However, cats are not naturally major fish eaters, and the idea is partly cultural.
Mercury and portions
Raw fish contains thiaminase, which destroys vitamin B1, and tuna only diets can cause deficiency. Some fish contain mercury. Feed fish as an occasional treat and use complete cat food. Do not give bones.
Fish in the feline diet
Domestic cats descend from the African wildcat, a desert hunter that rarely ate fish, but they readily accept fish. Fish oils supply EPA and DHA that support skin and joint health. Fish heavy diets can cause steatitis (yellow fat disease) from vitamin E deficiency.
Feeding guidance
Complete and balanced cat foods follow AAFCO standards. Raw fish risks include parasites and thiaminase. Tuna made for humans has too little taurine and can cause mercury exposure. Offer cooked, plain, boneless fish as an occasional treat, no more than 10 percent of daily calories. Cats with kidney disease need phosphorus control.
Based on data from the Association of American Feed Control Officials and Cornell Feline Health Center
