Many cats love the taste of fish and will readily devour it whether it's raw or cooked. However, repeated consumption of raw fish can cause a vitamin B deficiency, so it's worth the time and effort to cook it first. Fish is often marketed as a flavor that cats love, and while that is true for most cats, it is not part of their natural primary diet.
According to Pet Health Partnership, fish is not quite as nourishing as meat for cats, although it can add variety to their diet, and is a valuable protein source. It is also easily digested and rich in minerals. However, if cats overeat fish, they may decide they don't want it anymore. Further, too much fish may produce eczema, digestive troubles, and a bad-smelling cat.
Because of these health issues, follow the recommendations to not feed your cat fish more often than two or three times a week at most. Raw fish, in particular, if fed too often, will actually produce a vitamin B deficiency in the cat, causing serious disease.
Don't feed raw fish
Some types of fish contain thiaminase, an enzyme that breaks thiamine molecules in half and renders the B-vitamin useless in the body according to The Raw Feeding Community. Thiamine is essential to energy metabolism and if your cat doesn't get enough, it could end up with fatigue, weight loss and serious health issues affecting the heart and nervous system.
Just because your feline is eager to consume fish raw doesn't mean he should. Cooking makes it easier to remove bones that can injure your cat, according to Pet Health Partnership. Although cats in the wild do consume raw food, fish are rarely a part of their diet. This means that taking the extra time and effort to prepare cooked, filleted fish is essential to your cat's health.
Popular types of fish that contain dangerous levels of thiaminase when raw include
- Yellowfin and skipjack tuna
- Atlantic and Baltic herring
- White bass
Cooking whitefish for cats
Whitefish is another one of many types of fish that contain thiaminase, so when serving it to your cat, make sure it's cooked. Don't fry it or coat it in oil, however. Added fats both cooked and uncooked can cause intestinal upset to your cat according to WebMD.
Instead, bake the whitefish and carefully remove all bones before serving it to your cat. Each ounce of cooked, boneless whitefish delivers nearly six grams of protein along with a host of other vitamins and minerals, according to USDA FoodData Central. Whitefish is on the FDA's list of best choices for consuming fish, as it has lower levels of mercury.
Bake it: Wrap the fish in parchment paper and then in a layer of aluminum foil to hold in the moisture. Do not add any spices, as these can upset your cat's stomach, and the taste of fish is what your kitty craves. Bake at 400 degrees for 10 to 12 minutes or until tender. Let cool, flake into your cat's bowl, pour cooking juice over, and stir.
Cooking salmon for cats
Atlantic salmon, another fish on the FDA's list of best choices for food, is also thiaminase-free. When cooking salmon for cats, you can bake it in parchment paper and foil just like whitefish. However, thicker salmon steaks will need more cooking time—about 15 to 17 minutes, or approximately eight minutes per side. Flesh should be opaque pink with white lines when done, according to The Wild Salmon Company.
You can also poach salmon in a non-stick pan with one or two tablespoons of water or sodium-free broth to keep it from sticking. Three to four minutes per side on medium heat usually does the trick; however, if cooking a smaller piece from the tail end, you might need to reduce the time to two to three minutes on each side.
Other healthy fish choices
Limit feeding fish to your cat to just two or three times per week, advises Pet Health Partnership. Cats can enjoy a wide variety of both saltwater and freshwater species. Fish that are thiaminase-free, which also make the FDA's best choice list for low mercury levels, include:
- Freshwater trout
- Atlantic mackerel (Pacific mackerel does contain thiaminase per The Raw Feeding Community)
- Black sea bass
- Cisco/lake herring
- Pet Health Partnership: The Best Cat Food to Feed My Cat
- The Raw Feeding Community: Thiaminase in Raw Fish
- WebMD: Foods Your Cat Should Never Eat
- USDA FoodData Central: Fish, Whitefish, Mixed Species, Raw, 3 oz.
- The Wild Salmon Company: Heidi's Cooking Tips
- Food and Drug Administration: Advice about Eating Fish