Omega 3 for Cats: What It Is and What It Does for Their Joints
Diet, in particular, plays a vital role in your cat’s mobility and joint health. By incorporating specific nutrients and supplements into your cat's diet, you can help to keep their joints healthy right into their golden years.
Omega 3 fatty acids are fats your cat cannot make in useful amounts and has to get from food. Three matter most for joints: EPA, DHA and ETA. The forms cats can actually use come from marine sources, not from plant oils, and the main ones are oily fish, fish oil, krill oil and green lipped mussel. Green lipped mussel is the only common source of all three.
What omega 3 is, and why your cat has to eat it
Omega 3 fatty acids are a family of polyunsaturated fats. Cats cannot manufacture them in the quantities their bodies use, so every bit has to arrive through what they eat. In nutritional terms that makes them essential, in the strict sense of the word rather than the marketing one.
There is a second point that matters more for cats than for most species. Plant oils such as flaxseed and rapeseed contain omega 3 in the form of alpha-linolenic acid, or ALA. Converting ALA into the long-chain forms that tissues actually use is something cats do poorly. A cat given flaxseed oil is receiving omega 3 on the label and very little of the form that counts.
For a cat, the marine forms are the ones worth paying attention to.
EPA, DHA and ETA: the three that matter
EPA, or eicosapentaenoic acid
The long-chain omega 3 most often named on supplement labels and the most studied in companion animal nutrition. It comes from marine sources: oily fish, fish oil, krill and shellfish.
DHA, or docosahexaenoic acid
A structural fat, concentrated in nervous tissue, the brain and the retina. It comes from the same marine sources as EPA and the two are usually listed together on a label.
ETA, or eicosatetraenoic acid
Much less common, and the reason ingredient lists are worth reading closely. ETA is not present in meaningful quantities in standard fish oil. Green lipped mussel is one of the few natural sources of it, which is why it appears in joint supplements formulated to help maintain healthy joints in healthy cats.
A supplement can carry a high omega 3 figure on the front of the pack and contain no ETA at all. The three are not interchangeable.
Where omega 3 for cats comes from
Five sources come up in practice. They are not equivalent.
|
Source |
Provides |
Practical notes |
|
Oily fish in the diet |
EPA and DHA |
Sardines and mackerel are the usual suggestions. The amount arriving is impossible to control, the calories add up quickly, and a good number of cats simply refuse it. |
|
Fish oil |
EPA and DHA |
Widely available and inexpensive. Oxidises readily once opened, so storage and freshness matter. Smell puts some cats off their food. |
|
Krill oil |
EPA and DHA |
The fatty acids are bound in phospholipid form. Usually more expensive per capsule than fish oil. |
|
Green lipped mussel |
EPA, DHA and ETA |
A New Zealand shellfish, Perna canaliculus, with a broader fatty acid profile than fish oil and the practical source of ETA. Not suitable for cats with a known shellfish sensitivity. |
|
Flaxseed and other plant oils |
ALA only |
Cats convert ALA into long-chain forms poorly. Counts towards an omega 3 figure on a label without delivering much of what a cat uses. |
How to read an omega 3 label
Most of the confusion in this category comes from labels that quote the amount of oil rather than the amount of active fatty acid in it. A capsule containing 500 mg of fish oil might contain a third of that as EPA and DHA combined, or a good deal less.
Three things to look for:
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The EPA and DHA figures stated separately, per capsule, rather than a single combined omega 3 total for the oil.
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Whether ETA appears at all. If the source is fish oil, it will not.
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The daily amount recommended for a cat rather than for a dog or a person, since a scaled-down human product is not the same thing.
Freshness is the other half of it. Marine oils oxidise, and an oil that has turned smells of it. Small capsules used within their shelf life are easier to keep stable than a large bottle of liquid oil opened months earlier.
Weight comes before any supplement
No amount of marine oil offsets a cat carrying more weight than their frame is built for. Excess weight places more load on the joints that carry the weight, and heavier cats tend to move less, which turns into a loop that is harder to break the longer it runs.
Three things that make a measurable difference:
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Measure the food. Weigh it on kitchen scales rather than filling the bowl by eye. The measuring cups supplied with some foods are widely inaccurate.
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Feed a good quality complete diet. Rich in quality protein, light on fillers and artificial additives.
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Keep them moving. Short bursts of play, a wand toy, feeding puzzles and something to climb are more effective for a cat than anything resembling a walk.
If you are not sure what your cat should weigh, a nurse-led weight clinic at your practice will tell you, usually free of charge.
What about glucosamine, chondroitin and MSM
These three appear in a great many joint products, for cats and for dogs, and they are often listed first on the pack. It is worth being straightforward about them: the evidence supporting their use in cats is limited, and considerably weaker than the evidence base behind long-chain marine omega 3.
That does not make them harmful. It does mean that a product built mainly around them is asking you to pay for the ingredient with the least behind it, and it is a reason to read past the front of the pack.
Cats hide changes in how they move
Dogs limp. Cats reorganise their lives instead. A cat whose mobility is changing will often keep doing everything they used to do, just less, and lower down.
The things owners tend to notice first, often without connecting them:
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Jumping onto a chair first instead of straight onto the worktop.
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Sleeping somewhere new, usually somewhere lower.
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A coat that looks less well kept over the back and hips.
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Hesitating at the top of the stairs, or taking them one at a time.
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Missing the litter tray edge, or avoiding a high-sided tray.
None of these is dramatic on its own, which is exactly why they get put down to age. If several of them are true of your cat, it is worth a conversation with your vet.
Antinol® Joint Care Pro for cats
Antinol® Joint Care Pro is a blend of two marine lipid concentrates, built around PCSO-524®. It contains more than 90 free fatty acids, including EPA, DHA and ETA, in a small capsule designed to be given daily alongside your cat’s normal food. It is formulated to help maintain healthy joints and mobility in healthy cats, and it is recommended by vets
Antinol does contain green-lipped mussel and so we recommend you avoid use in cats with a known shellfish allergy.
Every order is covered by our 60-day money-back guarantee.
Frequently asked questions
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Can I give my cat a human omega 3 supplement?
It is not a good idea. Human capsules are sized for a person, so the amount in one capsule is far higher than a cat needs, and the flavourings and additives used in human supplements are not formulated with cats in mind. A product made for cats gives you a daily amount you can actually follow.
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What is the difference between fish oil and green lipped mussel?
Fish oil provides EPA and DHA. Green lipped mussel provides EPA, DHA and ETA, along with a wider range of fatty acids. If ETA matters to you, fish oil will not supply it.
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My cat’s food already says it contains omega 3. Is that enough?
It depends what form it is in and how much. Many complete diets meet the omega 3 requirement using plant oils, which supply ALA rather than the long-chain marine forms cats use readily. Check whether EPA and DHA are named specifically, and in what quantity, rather than relying on the words "with omega 3" on the front.
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Can omega 3 upset my cat’s stomach?
Marine oils are generally well tolerated. Introducing them gradually and giving them with food rather than on an empty stomach makes the change easier. If your cat has a known sensitivity to fish or shellfish, check the source of the oil before you start.
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How long is an omega 3 supplement usually given for?
It is a daily, ongoing part of the diet rather than a short course. Cats cannot store these fatty acids in any useful way, so the supply comes from what they eat each day.
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Can kittens have omega 3?
Long-chain omega 3 is a normal part of a growing cat’s nutrition and complete kitten diets are formulated to include it. If you are considering a supplement on top of that, check the product’s own guidance on age before starting.
