Is Cod Liver Oil Good for Dogs? Benefits, Risks & Dosage Guide

Cod liver oil has been a popular supplement for humans for generations, but is cod liver oil good for dogs too? For most dogs, the answer is yes—when used correctly. This nutrient-rich oil offers several health benefits, from supporting joint health to improving skin and coat condition. However, proper dosing and quality control are essential to avoid potential risks.

This guide explores everything UK pet parents need to know about cod liver oil for dogs, including its benefits, potential risks, and how to choose the right product for your furry friend.

What Is Cod Liver Oil?

Unlike regular fish oil that comes from whole fish bodies, cod liver oil is extracted specifically from the livers of cod fish. This makes a big difference in what nutrients your dog gets! The liver is where cod store fat-soluble vitamins, giving this oil a natural boost of:

• Omega-3 fatty acids (especially EPA and DHA)

• Vitamin A for healthy vision and immune function

• Vitamin D for strong bones and calcium balance

A typical teaspoon (5ml) of cod liver oil contains about 400mg of EPA and 450mg of DHA - the essential fatty acids that work wonders for your dog's health. You'll find this supplement in two main forms: liquid bottles (perfect for mixing into kibble) or capsules (easier for picky eaters when hidden in treats).

The quality of cod liver oil varies widely depending on where the cod fish were caught and how the oil was processed. The Marine Conservation Society recommends choosing products with MSC certification from UK or Norwegian waters for the most sustainable and pure options.

Benefits of Cod Liver Oil for Dogs

Skin and Coat Health

Many pet parents first consider cod liver oil when their dog develops dry, itchy skin or a dull coat. The omega-3 fatty acids in cod liver oil can help reduce inflammation and improve skin hydration.

Research published in the Journal of Veterinary Dermatology found that dogs receiving omega-3 supplements showed a significant reduction in itching and skin inflammation after 12 weeks. The essential fatty acids help maintain the skin's natural barrier function, reducing moisture loss and protecting against irritants.

Joint Health and Mobility

One of the most well-documented benefits of cod liver oil is its positive effect on joint health. The EPA in cod liver oil helps reduce inflammation in the joints, potentially easing discomfort for dogs with arthritis or joint issues.

A study by the Royal Veterinary College found that dogs with osteoarthritis showed improved mobility and reduced pain when given regular omega-3 supplements. This makes cod liver oil particularly valuable for older dogs or breeds prone to joint problems.

Brain and Eye Development

For puppies and young dogs, the DHA in cod liver oil supports healthy brain and eye development. According to research published by the British Veterinary Association, puppies whose diets were supplemented with DHA showed improved cognitive function and better visual acuity.

For pregnant and nursing dogs, cod liver oil can help support the development of their puppies' nervous systems. The PDSA recommends starting supplements in the final trimester of pregnancy for optimal benefits.

Heart Health and Immune Function

The omega-3 fatty acids in cod liver oil support cardiovascular health by helping to maintain healthy blood pressure and reducing inflammation. Regular supplementation may help protect against heart disease, especially in older dogs.

Additionally, the vitamin A and D content supports immune function, helping dogs fight off infections and maintain overall health. During the UK's darker winter months, the vitamin D in cod liver oil can be particularly beneficial when dogs get less natural sunlight.

Risks and When to Avoid It

While cod liver oil offers many benefits, it's not right for every dog. The biggest concern is vitamin A toxicity, which can happen if you give too much over time.

According to the Veterinary Medicines Directorate, signs of vitamin A overdose include:

• Joint pain and stiffness

• Dry skin or unusual skin changes

• Digestive problems

• In severe cases, liver damage

Some dogs might get loose stools when first starting cod liver oil. Others with specific health conditions should avoid it altogether:

• Dogs with liver disease

• Pets with pancreatitis

• Dogs on blood-thinning medications

• Pets scheduled for surgery (stop supplementation one week before)

Always check with your vet before adding any supplement to your dog's diet, especially if they have existing health concerns.

Vet‑Approved Dosage Guide — How Much Cod Liver Oil to Give

Giving the right dose matters more than anything else. UK vets usually start at 20 mg combined EPA + DHA for every kilogram of the dog’s weight each day. That equals about ½ teaspoon of liquid for a 20 kg Labrador, or one 500 mg cod liver oil capsule. The Colorado State University dosing chart sets a safe upper limit of 310 mg / kg^0.75 for arthritic dogs, but most dogs never need that

FEDIAF’s 2024 feeding guide reminds makers that vitamin A in cod liver oil supplements must not push a complete diet above 5 000 IU per 10 kg body‑weight. Use the table below as a rule of thumb, then ask your vet to adjust for age, arthritis severity or dog’s diet.

*Split large capsules or choose a pump bottle for toy breeds. Always start at half the target for a week to avoid loose stools.

How to Choose Quality Cod Liver Oil

Not all cod liver oil supplements are created equal. When selecting cod liver oil for your dog, look for:

1. VMD approval: In the UK, supplements making health claims must be authorized by the Veterinary Medicines Directorate and display a Vm number.

2. Sustainability certification: The MSC blue fish label indicates sustainable fishing practices.

3. Purity testing: Quality products should be tested for contaminants like heavy metals and PCBs.

4. Freshness: Rancid oil loses its benefits and may cause digestive upset. Choose products with added vitamin E as a natural preservative.

5. Transparent labeling: The product should clearly state the amounts of EPA, DHA, vitamin A, and vitamin D.

According to the British Veterinary Association, it's always best to consult with your veterinarian before starting any supplement regimen, especially for dogs with existing health conditions.

How to Add Cod Liver Oil to Your Dog’s Diet

The easiest way is to pour the measured liquid over regular food. Fatty flavour boosts appetite for picky eaters. For tiny terriers, pierce a capsule and drip half onto a lick‑mat. Mix well so the oil doesn’t sink. Pet owners who raw‑feed can weigh bone‑in meats first, then top up with liver oil to balance the fat‑to‑protein ratio.

Start with ½ dose for seven days. If stools stay firm, climb to the full amount. Purina UK notes that most dogs tolerate cod liver oil well when it comes from a trusted source, but it’s wise to speak to a vet first—especially if your dog is on meds or has Keep the bottle in the fridge, cap tight, and throw it away after 90 days or if it smells sour.

Tip: Combine the oil with a joint‑support chew rich in glucosamine for double joint care power, but subtract the chew’s vitamin A from your daily total.

FAQs

How often should a dog give cod liver oil?

Daily dosing keeps omega 3 levels steady. Split the amount between breakfast and tea for better absorption and less fishy breath.

What are the side effects of cod liver oil for dogs?

Loose stools, greasy coat or, with huge overdoses, vitamin‑A toxicity that harms the liver. Watch for vomiting, low energy or yellow gums and contact your vet.

How much cod oil for dogs?

Aim for 20 mg EPA + DHA per kg body‑weight (see table). Active dogs with arthritis may need up to 100 mg/kg under vet guidance, while puppies and young animals do well on 10 mg/kg for eye and brain

Conclusion

Yes, is cod liver oil good for dogs —when you pick a vet‑approved, MSC‑certified product and dose it to match your dog’s weight. The oil’s essential fatty acids fight inflammation, polish skin, support eye health and build strong bones by topping up natural vitamin D. Follow UK label rules, store the oil cold, and review the dose at each health check. Add these steps to your routine and you’ll give your dog a tasty boost for joints, heart health, and the immune system—all in one simple spoonful.