• Hahnbee Choi, Cert. CN

A Raw Feeder's Guide To Fish

Updated: Mar 14

Fish is a staple in raw diets as it provides many essential nutrients and counts as whole prey if fed whole. Everything you need to know about adding fish into a raw diet is outlined here!

Why Is Fish Added?

Fish is added as it is a rich source of essential nutrients, particularly vitamin D and omega-3 fatty acids Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA).

Fish To Feed

It is vital to choose lower-level small fatty fish to avoid biomagnification. Biomagnification is the concentration of toxins in an organism that increases as you move up the food chain.

Examples of Appropriate Fish:

∙ Anchovy

∙ Sardines

∙ Smelt

∙ Mackerel

∙ Salmon

∙ Herring

Fish Not To Feed

Fish to avoid are predatory and larger fish such as king mackerel, tuna, swordfish, and shark due to biomagnification. Biomagnification is the concentration of toxins in an organism due to consuming other plants or animals where the toxins are more widely distributed. The pollutants or toxins increase in the tissues as it moves up the food chain. And unfortunately, these toxins cannot be excreted, so they get passed onto the next trophic level. Pollutants are absorbed by microscopic phytoplankton at the bottom of the food chain, smaller fish eat the zooplankton, then a bigger fish eats that fish, and finally, the highest trophic level receives the maximum accumulation of the pollutants. Whether natural or human-made, there are many toxins in the world that animals consume daily and since there is no avoiding them, at least we can avoid feeding these toxins in significant quantities by not feeding predatory animals.


If you are feeding a freshly caught fish, it must be frozen at a minimum of 3 weeks or more to ensure that any parasite or worms in the animal are properly killed to make it fit for feeding. If you purchase the fish from a raw feeding supplier or grocery store, it will already have been frozen before your purchase and can be fed immediately.

How To Feed

As a rough guideline, fish should make up around 1oz (28g) of fish for every 20lb (9kg). Other guidelines include 15% of the diet being fish. If you have a meal plan, the proper amount will be included. When first introducing fish, many dogs can turn their noses up. To persuade them, you can try grinding the fish, freezing, and offering the fish first before the rest of the meal. Freeze-dried or dehydrated fish are another great way to change the texture and smell.


Fish can be sourced from raw feeding suppliers, grocery stores, or fishing (wild-caught). Avoid fish in vegetable oils (olive oil is an exception), tomato sauce, smoked, or added sodium. Ideally, find frozen fish or canned fish in water with no added salt.

Sensitivities & Allergies

Feed the fish that works for them if the dog is sensitive/allergic to a specific fish only. If all fish must be avoided, supplements can be used for Vitamin D and omega-3 fatty acids (EPA/DHA). A supplement such as NOW Vitamin D3 drops can be used for vitamin D. For EPA & DHA, turn to other foods such as shellfish (if applicable), fish oil (if applicable), and other foods such as brain.


Thiaminase is an enzyme that breaks down vitamin B1 or thiamine. Many raw feeders are aware of the thiaminase dilemma and have seen the recommendation to feed and store thiaminase fish away from the rest of the meal. While this is a safe rule to follow, it will not leach into the whole meal if you feed whole fish unless a thiaminase-containing fish is completely ground in, which increases the surface exposure. If you'd like to be on the safer side, feed/store all thiaminase-containing fish separately from the meal. Cooking and steaming deactivates thiaminase; therefore, tinned or cooked/steamed fish can be fed without worry. Learn more about thiaminase here and here.

Fish is essential to raw diets to supply essential nutrients. But with anything, it must be fed in moderation and with as much quality and variety as possible. I hope you learned something new today & Always Keep Exploring!