Can I Give My Dog Cod Liver Oil Every Day? The Real Scoop

Everybody wants their dog to feel amazing—maybe that’s why more people are reaching for supplements like cod liver oil and adding them to their dog’s food. But just because something is healthy in small doses doesn’t mean more is always better, right?

Cod liver oil sounds like a miracle: omega-3s, vitamins A and D, and a track record for helping with joint health, dry skin, and even a shinier coat. But here’s the catch: dogs' bodies don’t always need the same things every day, and some vitamins can build up to unhealthy levels if you go overboard.

If you’ve ever wondered whether you can just pour cod liver oil on your dog’s food every morning, you’re not alone. Lots of pet owners ask this after reading glowing reviews and seeing fish oil popping up in dog food commercials. You want the best for your pup, but it helps to know what’s safe, what’s risky, and how to avoid accidentally making things worse.

• Why Do People Give Dogs Cod Liver Oil?
• How Much Cod Liver Oil Is Safe?
• Risks of Daily Cod Liver Oil Use in Dogs
• Tips for Using Cod Liver Oil the Right Way

Why Do People Give Dogs Cod Liver Oil?

People give dogs cod liver oil because it’s packed with nutrients that can be tough to get from regular dog food. The main draws are omega-3 fatty acids, plus vitamins A and D. These ingredients show up a lot in simple Google searches for natural ways to boost dog health. When I first started researching it for my own pup, I kept seeing stories about dogs itching less, moving better, and looking like they just came home from the groomer.

Let’s break down why pet owners trust this supplement. Here’s what you’re usually getting:

• Omega-3s (EPA and DHA): Good for the heart, joints, and skin. Some studies found that dogs with arthritis show more pep after a few weeks of omega-3s. Their coat may look glossier, and itching can settle down.
• Vitamin A: Helps keep their eyes healthy, supports the immune system, and is crucial for skin and mucous membranes. Still, too much isn’t good, but we’ll get to that in a bit.
• Vitamin D: Helps the body use calcium, so their bones and teeth stay strong. Growing pups and older dogs benefit most, especially if their regular food is low in vitamin D.

Another reason people add cod liver oil to their dog’s diet is that it’s sometimes easier than buying separate supplements. Instead of juggling pills and powders, you squirt a little oil into a bowl. Easy. Plus, it’s got a mild fishy taste that many dogs actually love. I’ve seen even the pickiest eaters lick their bowls clean when there’s a drop of fish oil drizzled on top.

Here’s a quick comparison that shows the main nutrients in cod liver oil versus standard fish oil for dogs:

Bottom line, the reason so many folks are reaching for cod liver oil is because it delivers key nutrients in a quick, simple way—and some dogs clearly benefit, especially seniors or those with skin and joint issues.

How Much Cod Liver Oil Is Safe?

Getting the dose right with cod liver oil is key. Too little might not help your dog much, and too much could actually cause more trouble than it’s worth. You don’t want to play guessing games with anything you give your pup every day, especially when it comes to stuff like vitamin A and D — both of which are easy to overdo.

For everyday use, most vets suggest:

• Small dogs (less than 20 lbs): 1/4 teaspoon per day
• Medium dogs (20-55 lbs): 1/2 teaspoon per day
• Large dogs (over 55 lbs): up to 1 teaspoon per day

These numbers aren’t just random. They’re based on how much EPA and DHA (the omega-3s that actually matter) your dog’s body can handle, plus the vitamin A and D levels that won’t push things into the danger zone. But not all dog health supplements are created equal — some cod liver oils have way more vitamins than others. Always check the label’s daily values, and compare those numbers with your dog’s other food or treats to avoid accidental overdosing.

Sometimes a vet might recommend a different amount, especially if your dog has joint issues, allergies, or dry skin. Never double up on dosing without checking. And skip the DIY refills — those huge bottles meant for people can have much higher concentrations and different purity standards than those made just for pets.

Always start small. If your dog’s food already has added oils or vitamins, you may want to use even less. Keep an eye on your dog for any changes in appetite, energy, or bathroom habits — those can be your first warning signs that something’s off with their supplements.

Risks of Daily Cod Liver Oil Use in Dogs

Before you reach for that bottle every day, it’s good to know the risks of daily cod liver oil for dogs. The part most people forget is that cod liver oil is packed with vitamins A and D. Both vitamins are fat-soluble, so the body stores the extra instead of flushing it out. Over time, high doses can actually backfire with something called hypervitaminosis—which just means dangerously high levels of those vitamins in your dog's system.

Here’s where things get serious: signs of vitamin A or D overdose can sneak up on you. Maybe your dog seems a little stiff and you assume it’s arthritis, but joint pain, bone abnormalities, or even loss of appetite can all be red flags. With enough overload, you might even see kidney or liver issues. Not fun and definitely not the outcome anyone wants from a dog health supplement.

Too much cod liver oil can thin your dog’s blood, too. This means if they have surgery or get injured, their blood may not clot like it should. If your dog is already on any meds for pain or inflammation—like NSAIDs—there’s a real risk of side effects or interactions. Plus, omega-3s are awesome in the right amount, but flooding your pup with them every day can upset their stomach. Diarrhea and vomiting are classic signals things are off.

• Vitamin A Toxicity: Weakness, bone pain, peeling skin, loss of appetite.
• Vitamin D Toxicity: More drinking and peeing, vomiting, even kidney issues over time.
• Upset Stomach: Nausea, diarrhea, greasy stools.
• Blood Thinning: More bruising, slow healing after cuts or surgery.

Vets often see toxicity from overuse of supplements, not just from eating too much actual food. According to some pet nutrition reports, even doses just 2-3 times higher than recommended can start to cause problems after a few weeks.

The best tip? Don't fall into the 'more is always better' trap. Stick to the dose a vet recommends—usually based on your dog’s weight and health needs. If you spot anything weird, like a change in energy or tummy troubles, take a break and talk to your vet before you keep using the supplement every day.

Tips for Using Cod Liver Oil the Right Way

Giving your dog cod liver oil can be helpful, but only if you do it correctly. Mess up the dosage or ignore your dog’s unique needs, and you could create more problems than solutions.

• Talk to your vet first. Always check with your vet before starting dog health supplements. They’ll know if it’ll mix well with any meds or if your specific dog actually needs it.
• Stick to the right dose. Most vets say a safe starting point is about 20 mg EPA (one of those good omega-3s) per pound of your dog each day. But, don’t guess—your vet should confirm the right dose for your dog’s size, age, and health.
• Read the label. Not all cod liver oil is the same. Some have way more vitamin A or D than others, and these can build up in your dog’s system if you aren’t careful. High levels of these vitamins can turn toxic fast. Look for products made for dogs with clear dosing instructions.
• Watch for side effects. Signs your dog’s getting too much cod liver oil include upset stomach, loose stools, loss of appetite, or just acting "off." If you see these, stop the supplement and call your vet.
• Don’t mix with other fish oil. If your dog is already getting fish oil or eats food with added omega-3s, let your vet know. Too much can throw off the nutrition balance.

Here’s a quick look at what you should pay attention to when adding cod liver oil to your dog’s diet:

And remember, daily use isn’t always required. Sometimes, every-other-day or just when skin or joint issues show up is enough. Follow your vet’s advice; they know your dog’s history.