Seafoodbuddy Sharing Blog

The Raw Fish Question

Cats and fish seem like a natural pairing — but is raw fish actually safe for your cat? The short answer is: occasionally and in small amounts, it's unlikely to cause harm, but feeding raw fish regularly comes with real risks that every cat owner should understand.

The Risks of Feeding Raw Fish to Cats

1. Thiaminase: The Hidden Enzyme

Many raw fish species — including tuna, carp, and herring — contain an enzyme called thiaminase, which breaks down thiamine (vitamin B1) in your cat's body. Thiamine is essential for neurological function. Cats fed raw fish regularly can develop thiamine deficiency, leading to symptoms like loss of appetite, seizures, and in severe cases, death.

2. Bacterial Contamination

Raw fish can harbour harmful bacteria including Salmonella and Listeria. While cats have more acidic stomachs than humans, they are not immune to foodborne illness. Symptoms of bacterial infection include vomiting, diarrhoea, lethargy, and fever.

3. Parasites

Raw fish can contain parasites such as flukes and roundworms that can infect cats. Some parasites are killed by freezing, but not all — and home freezing is not always sufficient to eliminate the risk.

4. Mercury and Heavy Metals

Larger fish like tuna and swordfish can accumulate mercury and other heavy metals. Regular consumption of these fish — raw or cooked — can lead to mercury toxicity over time, particularly in smaller cats.

Why Freeze-Dried Fish Is a Safer Alternative

Freeze-drying offers the best of both worlds: the natural nutrition and flavour of real fish, without the risks associated with raw feeding.

• Thiaminase is deactivated — The freeze-drying process neutralises thiaminase, making the treat safe for regular feeding without the risk of thiamine deficiency.
• No bacterial risk — Freeze-dried treats are processed to eliminate harmful bacteria, making them far safer than raw fish straight from the market.
• Nutrients preserved — Unlike cooking, freeze-drying preserves omega-3 fatty acids, taurine, and other heat-sensitive nutrients at their natural levels.
• Convenient and shelf-stable — No refrigeration needed, no preparation required, and no mess.

Can Cats Have Any Raw Fish at All?

An occasional small piece of fresh, sushi-grade fish is unlikely to cause harm in a healthy adult cat. However, it should never be a regular part of their diet. If you want to give your cat the flavour and nutrition of real fish safely and consistently, freeze-dried is the smarter choice.

The Bottom Line

Raw fish carries real risks for cats — from thiamine deficiency to bacterial infection and parasites. Freeze-dried seafood treats give your cat everything they love about fish (the smell, the taste, the nutrition) without any of the downsides.

Explore our best-selling freeze-dried seafood treats — the safe, natural, and nutritious way to treat your cat to real seafood every day.