Why fish oil is one of the best supplements for dogs and cats

Why are supplements worthwhile for pets as well?

When we go shopping, many of us consider vitamins and supplements for our own daily lives. But how often do we stop to think whether our pet gets everything it needs from just basic food? Dogs and cats are surprisingly similar to us in this respect: some important nutrients are difficult to obtain in sufficient amounts from ordinary dry or canned food.

One such nutrient is omega-3 fatty acids—especially EPA and DHA obtained from fish oil. These fatty acids have become increasingly important in pet wellness research, and there is already abundant scientific evidence of their benefits. In this article, we will review what omega fatty acids actually are, why they are beneficial for dogs and cats, and how to find a high-quality option for your pet.

What omega-3 and omega-6 fatty acids are—and why balance is important

Fatty acids belong to the so-called essential nutrients: the body cannot produce them itself, so they must be obtained from the diet. Omega fatty acids are divided into two main groups, omega-3 and omega-6, both of which are necessary—but for very different functions.

• Omega-6 fatty acids (such as linoleic acid and arachidonic acid) are abundant in most commercial pet foods. They support normal cell function, but excessive omega-6 relative to omega-3 increases the body’s sensitivity to inflammation.
• Omega-3 fatty acids (alpha-linolenic acid or ALA in plant-based oils, and EPA and DHA in fish-based oils) balance the situation. They act in the body to reduce inflammation and support the function of the heart, joints, skin, and brain.

The bodies of dogs and cats cannot convert ALA sufficiently into EPA and DHA, so fish oil plays a key role here: it directly contains bioactive EPA and DHA, which the body can easily utilize. This is why veterinary nutritional research particularly recommends fish oil-based supplements over plant oils.

Benefits of fish oil for the skin and coat shine of dogs and cats

One of the most visible signs of the effects of omega-3 is the condition of the coat. If your dog’s or cat’s coat feels rough, flaky, or looks lifeless, the cause may be a deficiency of fatty acids. EPA and DHA participate in maintaining the structure of skin cells and strengthening the skin’s natural moisture barrier.

In practice, fish oil supplementation can show effects quite quickly: many pet owners notice within a few weeks that the coat begins to shine and feels softer. Skin flaking decreases and itching eases, especially in allergic or sensitive-skinned pets. Fewer substances causing inflammatory reactions – so-called prostaglandins – are produced as the omega-3 to omega-6 ratio balances out.

The situation is particularly significant in cats: cats are meticulous about grooming, but dry or irritated skin can cause excessive licking and skin damage. Fish oil supports the integrity of a cat’s skin naturally without chemical additives.

The effect of omega fatty acids on joint and heart health

The anti-inflammatory properties of fish oil are especially valuable for pets suffering from joint problems or aging. Osteoarthritis is a common condition in dogs and cats, causing pain primarily due to inflammatory reactions in joint tissue.

Studies show that EPA and DHA reduce the production of enzymes that cause inflammation in joint tissue. Practically, this means that dogs and cats with osteoarthritis given fish oil supplements move more freely and experience less pain. In one study, cats fed an omega-3 enriched diet combined with supplements showed significant improvement in mobility measured by objective methods.

Fish oil has several beneficial effects on heart health:

• It can reduce triglycerides in the blood, which is particularly important for pets with heart disease.
• EPA and DHA can protect the heart from arrhythmias – especially in cats, where heart disease often involves a risk of blood clots, fish oil can act as a natural blood thinner.
• Blood pressure may moderately decrease with regular use of fish oil.

These results do not mean that fish oil replaces medication prescribed by a veterinarian – but it can be a valuable complementary support in comprehensive care.

How to choose a high-quality fish oil for your pet

There are many types of fish oils on the market, and quality varies significantly. Here are the key factors to pay attention to:

• EPA and DHA content: These are the most important active ingredients in fish oil. The higher the EPA+DHA content per milliliter or capsule, the more effective the product. Veterinary nutrition experts recommend at least 225 mg EPA+DHA per milliliter for liquid oil.
• Origin of raw material: Oil derived from wild fish (salmon, sardine, anchovy) is of higher quality than that from farmed fish. Atlantic salmon and sardine are good options – they provide abundant EPA and DHA.
• Purification process: High-quality fish oil is purified from heavy metals and other contaminants by molecular distillation or another certified method. Check the product packaging or manufacturer’s website for details.
• Oxidation protection: Fish oil oxidizes easily, which makes it rancid and ineffective. A good product contains a natural antioxidant, such as vitamin E, to prevent oxidation.
• Liquid vs. capsules: Liquid oil allows for more precise dosing than capsules, which is especially important for small pets. It also mixes easily into food.
• Pet-specific product: Fish oil intended for humans is not always suitable for pets – for example, some products contain flavorings or additives that are not appropriate for dogs or cats. Always choose a product specifically developed for pets, such as Atlantic salmon oil for dogs and cats or Atlantic sardine oil for dogs and cats.

Dosage and practical feeding tips

Dosage always depends on the pet’s size, age, and health condition. The following guidelines are general – precise dosing can be found on the product packaging or from your veterinarian, especially if the pet has a medical condition.

For dogs

Veterinary literature generally recommends 40–70 mg EPA+DHA per kilogram of body weight per day for general well-being. For therapeutic purposes, such as osteoarthritis treatment, doses may be higher – even 100–220 mg/kg – but this is always done under veterinary supervision.

• Small dogs (under 10 kg): About 0.5–1 ml of liquid fish oil per day.
• Medium-sized dogs (10–25 kg): About 1–2 ml per day.
• Large dogs (over 25 kg): About 2–4 ml per day.

Always start with a smaller dose and gradually increase it over a few weeks – this way, stomach issues are less likely to occur. Mix the oil directly into the food; most dogs like the taste of fish oil and will eat it willingly.

For cats

Omega-3 research in cats is less extensive than in humans and dogs, but the commonly used dose is about 30 mg EPA+DHA per kilogram per day. In practice, this means about 0.25–0.5 ml of liquid fish oil per day for a small cat.

• Important for cats: Do not give cats too much fish oil containing vitamin D supplements, as cats are sensitive to vitamin D overdose. Pet-specific products are dosed safely.
• Many cats are more finicky than dogs. Try mixing the oil into wet food or directly on top of dry kibble – it often works.
• Start with a very small dose (e.g., a few drops) and increase slowly.

General tips for both:

• Store fish oil in the refrigerator after opening and use the product within the time indicated on the packaging – rancid oil is not beneficial.
• The effects of fish oil usually appear after weeks or months, not days. Be patient.
• If the pet has an underlying illness, is on medication, or is pregnant or nursing, consult a veterinarian before starting supplements.
• Avoid overdosing: excessive omega-3 can impair blood clotting and cause stomach issues.

Summary

Omega-3 fatty acids – especially EPA and DHA from fish oil – are among the best researched and most beneficial supplements for dogs and cats. They support skin and coat condition, ease joint problems, protect the heart, and balance the body's inflammatory responses in many ways.

The most important thing is to choose a high-quality product designed for pets, with a clearly stated EPA+DHA content, made from pure, known raw materials. It is advisable to start the dose cautiously and monitor the pet's condition. After just a few weeks of use, many owners notice positive changes in the coat and mobility.

Fish oil supplements do not replace high-quality basic food or veterinary care – but they can be the small, easily implemented daily action that, in the long term, makes a pet's life more comfortable and healthier.