Flounder

24 foods contain this ingredient

Protein Fish allergen group

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About Flounder

Flounder is a flatfish species sometimes included as the named fish protein in dog and cat food recipes.

Flounder is used in pet foods as a lean, high‑quality animal protein that provides essential amino acids, B vitamins (such as B12 and niacin), selenium and modest amounts of omega‑3 fatty acids to support skin, coat and overall health. It can be a suitable option for dogs and cats, but sourcing and processing matter because raw fish can carry parasites, some pets may have fish allergies, and manufacturers must ensure recipes are balanced to meet species‑specific needs (for example taurine for cats).

Derived from: flatfish (flounder species)
Primary role: animal protein source

Why it's used

Some multi-fish and fish-focused recipes list flounder alongside other species like salmon, herring, or mackerel to diversify the protein and fatty acid sources in a formula. Its mild flavor and lean composition also make it a common choice for recipes marketed toward pets transitioning to a fish-based diet.

Common concerns

Raw fish and parasites Fish, including flatfish like flounder, can serve as an intermediate host for parasites (including tapeworms and roundworms), which is why veterinary parasitology references advise against feeding raw or undercooked fish to dogs and cats.
Fish allergen Fish is one of the more commonly reported food allergens in dogs and cats, and flounder falls under the same fish allergen group as other finfish species.
Thiaminase in some raw fish Certain raw fish contain the enzyme thiaminase, which can break down thiamine (vitamin B1); commercial pet food processing (cooking) inactivates this enzyme, which is one reason manufacturers rely on cooked or properly processed fish rather than raw.

Also relevant

Because flounder is a lean fish, formulators typically need to add supplemental fat sources to balance the recipe's overall energy and essential fatty acid content.

4 sources cited