Omega-3 fatty acids play a vital role in your dog’s health. They support skin barrier function, reduce inflammation, nourish the joints, modulate immune responses and maintain brain and nervous system function. But how do you know if your dog is actually getting enough?

And did you know that too much omega-3, especially without the right nutritional balance, can cause harm rather than help?

Many pet parents add fish oil or sardines to their dog’s bowl hoping to ease itching, stiffness or anxiety. But without testing, it is impossible to know whether your dog needs more, less or something entirely different. The Omega-3 Index takes the guesswork out. It is a simple blood test that measures the amount of EPA and DHA, the two most important omega-3s, inside your dog’s red blood cells. This gives a reliable picture of their long-term omega-3 status over the past few months and helps guide dietary or supplement decisions with precision.

Why omega-3s matter and why balance counts

EPA and DHA are long-chain omega-3 fatty acids found primarily in marine sources like fish and algae. They are well known for their anti-inflammatory effects, particularly in the skin and joints, but their influence extends much further. These fatty acids support immune regulation, coat quality, gut-brain communication and cognition in ageing dogs.

Dogs cannot produce EPA or DHA in significant amounts and while plant-based oils like flaxseed contain ALA, the conversion rate to EPA and DHA is extremely low. Without oily fish or marine-based supplements, many dogs are significantly under-supplied, especially those eating dry or processed diets.

At the same time, commercial foods are typically high in omega-6 fatty acids from poultry fat, sunflower oil and grain-based ingredients. While omega-6s are essential, they compete with omega-3s in the body and tend to promote inflammation when unbalanced. The goal is not to eliminate omega-6, but to restore a healthier ratio. In most cases, that means increasing omega-3 intake in a targeted way.

Too much of a good thing

Although omega-3s offer many benefits, they are also highly unsaturated fats and can be prone to oxidation. Giving high doses without sufficient antioxidant support, particularly vitamin E, can lead to increased oxidative stress. This may counteract the intended anti-inflammatory effect and in some cases make things worse. Dogs on high-fat diets or managing chronic inflammation may be especially sensitive.

Using the Omega-3 Index allows you to fine-tune supplementation to ensure it is both effective and safe. Rather than assuming more is better, you can make decisions based on the actual amount of omega-3 incorporated into your dog’s cells.

The problem with guessing

Many people try to help their dog by adding a human omega-3 capsule to their bowl. In some cases that may help, but without knowing the baseline level or measuring the response, there is no way to know if it is doing what you hope. EPA and DHA content varies widely between products and few are tested for oxidation, stability or purity in animals.

The Omega-3 Index shows whether your chosen supplement or diet is actually being absorbed and used. It provides a target range to guide dosage and gives you the confidence to adjust with purpose, not guesswork.

Quality matters

Omega-3s are fragile. They degrade with heat, light and air exposure and can go rancid in storage or during processing. Rancid oils lose their health benefits and may even contribute to inflammation. Choosing a high-quality, marine-based supplement that is properly stored, regularly tested and clearly labelled is essential. If it smells strongly fishy or sour, it is probably not fresh.

Which dogs benefit most

All dogs need omega-3s, but some need more than others. Skin conditions such as atopic dermatitis, joint disease, gastrointestinal inflammation, age-related cognitive decline and immune-mediated issues all increase demand. Dogs with poor coat quality, frequent itching or anxiety-like behaviour may also benefit. In these cases, maintaining a high-normal Omega-3 Index may support broader treatment goals and improve resilience.

What about wholefoods

Wholefood sources can contribute to omega-3 intake as part of a fresh food plan or alongside supplements. Sardines in springwater, salmon, anchovies, fish skins and green-lipped mussels are all rich in EPA and DHA. These can be rotated into the diet several times per week, adjusted to match energy needs and introduced gradually to avoid digestive upset.

Why testing matters

The Omega-3 Index measures what is actually being used in the body, not just what is going into the bowl. It reflects the proportion of EPA and DHA in red blood cell membranes, which mirrors long-term tissue status. This makes it one of the most accurate tools available for tracking omega-3 health in dogs.

For dogs already on omega-3 supplements, it shows whether the current plan is working. For those not yet supplemented, it offers a starting point. And for any dog with chronic health concerns, it allows for targeted, measurable intervention. Once optimal levels are reached, retesting every six to twelve months helps ensure your dog stays within the healthy range.