Fish or Fish Oils
- RFFDMSUK
- Dec 29, 2024
- 4 min read
Updated: Mar 2
🐟 The Nutritional Value of Oily Fish in a Dog’s Diet
Small oily fish are among the richest natural sources of long‑chain omega‑3 fatty acids, especially EPA (Eicosapentaenoic Acid) and DHA (Docosahexaenoic Acid). Dogs cannot produce meaningful amounts of these fatty acids themselves, so they must come from the diet. Including oily fish helps balance the fatty‑acid profile of meals, particularly when feeding farmed meats, which naturally contain lower omega‑3 levels.
🧠 How EPA & DHA Support Normal Canine Physiology
EPA and DHA contribute to several important nutritional and physiological functions:
Supporting normal brain and nervous system development and cognitive processes
Contributing to the maintenance of healthy vision
Helping maintain skin hydration and supporting normal coat quality
Participating in the body’s natural inflammatory regulation
Supporting a balanced gut microbiome when combined with probiotics
Contributing to normal heart and circulatory function
Supporting the body’s natural antioxidant defences
These roles reflect how omega‑3s function nutritionally within the body, rather than implying medical outcomes.
⚠️ When Omega‑3 Intake Is Low
Low intake of long‑chain omega‑3s may be associated with:
Dull or brittle coat
Dry or flaky skin
Slower recovery after minor scrapes
Recurrent irritation in ears or skin folds
Changes in behaviour or mood
These signs can have many causes, so persistent issues should be discussed with a veterinary professional.
🐠 Whole Fish vs. Bottled Fish Oils
Many owners consider fish oils for convenience, but whole fish offers several nutritional advantages.
Considerations with bottled fish oils
Oxidation can occur quickly once opened, reducing nutritional value
Environmental contaminants may be more concentrated in extracted oils
Why whole fish is often preferred
Whole fish provides:
EPA & DHA in a naturally occurring, highly bioavailable form
Additional nutrients such as selenium, calcium, iodine, niacin, and coenzyme Q10
A food‑based source that aligns with species‑appropriate feeding principles
This makes whole fish a practical and nutrient‑dense choice for many raw feeders.
🦪 Green‑Lipped Mussels as an Omega‑3 Source
Green‑lipped mussels contain a unique omega‑3 fatty acid, ETA (Eicosatetraenoic Acid), which participates in the body’s natural inflammation‑modulating pathways. They also supply amino acids, minerals, and glycosaminoglycans, making them a versatile addition to many diets.
They can be used alongside oily fish or as an alternative when fish isn’t tolerated.
🐟 Best Oily Fish Choices for Dogs
Small oily fish tend to be lower in environmental contaminants and higher in omega‑3s.
Omega‑3 content per 100g
Fish Type | EPA & DHA (mg) |
Sardines | 2,760 mg |
Mackerel | 2,298 mg |
Salmon | 1,962 mg |
Herring | 1,571 mg |
Sprats | 1,400 mg |
Other suitable options
Whitebait — rich in protein and calcium
Green‑lipped mussels — highly bioavailable omega‑3s
Anchovies — nutrient‑dense and generally sustainable
Fish to avoid
Tuna — larger species accumulate more mercury and heavy metals
Crabsticks — highly processed and low in nutritional value
🍽️ How Much Oily Fish to Feed
The ideal amount depends on the rest of the diet:
Dogs eating varied, organic, or grass‑fed meats often need less additional omega‑3
Dogs eating mostly farmed meats may benefit from more oily fish
Dogs on non‑raw or heavily processed diets may require the highest inclusion to balance omega‑6 to omega‑3 ratios
Our Fish Calculator helps determine an appropriate weekly amount based on diet type and feeding volume.
To keep meals balanced:
Spread fish portions across several meals
If weight loss is needed, incorporate fish within the meal rather than adding extra calories (e.g., using a surf & turf mince)
🐾 If Your Dog Won’t Eat Oily Fish
Some dogs dislike the texture or smell of raw fish. Alternatives include:
Algae oils provide EPA and DHA without relying on fish, though they do not supply the additional minerals and proteins found in whole fish.
Green‑lipped mussels are another useful option, and many owners source Canumi Monkhouse Liver, Mackerel, and Green‑Lipped Mussels.
⚠️ Special Considerations for Epileptic Dogs
Some dogs with certain types of epilepsy may require specific omega‑3 sources. A pro‑raw or holistic veterinarian can help determine the safest approach for individual cases.
🥫 Using Tinned Fish
Tinned fish varies widely in quality.
If using tinned fish:
Choose spring‑water varieties
Select BPA‑free tins
Prioritise higher‑quality options such as Canumi’s Monkhouse Liver, Mackerel, and Green‑Lipped Mussels
Why avoid tinned fish in oils or sauces:
Oils, brines, salts, and sugars can remain absorbed even after rinsing
Heat processing reduces nutrient availability compared to fresh or frozen fish
🧼 Safe Handling Practices
To ensure safe feeding:
Freeze fresh, unfrozen fish for three weeks before feeding to reduce parasite risk
Prawns and squid can be fed raw only when sourced safely (your own research will be needed on this); otherwise, cook them
Defrost and prepare fish in whichever form your dog prefers — whole, chopped, or blitzed as a topper
🌍 Sustainability and Ethical Sourcing
Choosing ethically sourced fish supports marine ecosystems and helps maintain healthy fish populations. Small species such as sardines, sprats, and anchovies are often considered more sustainable choices.
Incorporating small oily fish into your dog’s diet provides a rich source of omega‑3s, high‑quality protein, and essential minerals. Thoughtful sourcing and balanced feeding help ensure your dog receives the full nutritional value while avoiding unnecessary risks.
