Do Dogs Need Supplements? What Even the Best Dog Food Misses

Written by Lucy Fitzgerald, Founder, WYLDR. Reviewed by Katie McCaul, RNutr, The Pet Diet. Updated 25 June 2026.

The short answer: Some dogs benefit from a daily supplement because everyday processing and feeding can leave predictable gaps, mainly omega-3, prebiotic fibre and antioxidants. A clean, targeted supplement adds these back alongside a good diet. Not every dog needs one, and persistent problems are a job for your vet, not a supplement.

Most dog owners ask the same fair question at some point: if I am already feeding a good food, does my dog actually need a supplement on top? It is worth answering honestly, because the pet shelf is full of products that promise a lot and change very little. So let us be straight from the start. Whether dogs need supplements depends less on the brand on the bag and more on what happens to food before it reaches the bowl. A good diet can still leave predictable gaps. This guide explains what those gaps are, why they exist in kibble and in raw feeding, how to decide whether a daily supplement earns its place, and what separates one worth giving from one that just adds to the cupboard.

Your dog's food is good. The point of this article is simply what it might be missing.

What "complete" food actually means

In short: In the UK, "complete" means a food is formulated to meet a dog's basic nutritional needs on its own, while a "complementary" food is meant to be fed alongside a main diet. The label tells you the role a product plays, not how good it is.

In the UK, "complete" is a regulated term. A complete food is formulated to meet a dog's basic nutritional requirements on its own. A complementary food is designed to be fed alongside the main diet rather than to replace it. Both are legitimate, and the label is telling you the role the product is meant to play, not how good it is.

Here is the part worth understanding. "Complete" means a food meets the minimum requirements a dog needs within that bowl. It does not mean every one of those nutrients is easily absorbed, or that the balance is optimal for your individual dog at every life stage. To be labelled complete, a food only has to meet the lowest nutritional level a dog needs to get by. Minimums are a floor, not a ceiling. That gap, between "meets the minimum on paper" and "what actually reaches your dog day to day", is where the supplement question lives. A supplement is not an admission that the main food is poor. It is a way of topping up the specific things that are easiest to lose.

Why complete food can still have gaps

In short: Two things create gaps. The guidelines for "complete" food aim at preventing deficiency rather than reaching an optimum, and almost all food is processed in some way, which can reduce certain nutrients along the way.

Most dog food has been processed in some form for our convenience. Even a raw diet is usually built from farmed meat and selected cuts rather than whole prey, and some of the nutrients found in a natural, varied diet are reduced along the way. On top of that, the official requirements for a complete food concentrate on the essentials: supporting life stages and preventing the disorders that come from clear deficiencies or excesses. Research tends to be done in response to a suspected problem rather than to chase an optimum, partly because that research is costly to run. The result is a sensible floor, not a ceiling. It is not unlike feeding a person. A diet of ready meals and takeaways will keep you going day to day, but living on convenience food alone misses what fresh, whole ingredients bring. The same is true in the bowl.

Why processing leaves gaps

In short: A complete food only has to hit the minimum, not the optimum, so a few extras are easy to under-deliver: omega-3 balance, prebiotic fibre and antioxidants. High heat, especially the extrusion used to make kibble, can reduce them further.

Three parts of an optimal diet are easy to under-deliver, because a complete food only has to meet minimums rather than optimise everything: omega-3 balance, prebiotic fibre and antioxidants. High heat makes this worse. Most dry dog food is made by extrusion, a high-temperature, high-pressure process that cooks the mix and shapes it into kibble. Heat is efficient, it makes food safe and shelf-stable, and it is why dry food is so convenient. But these three nutrients are sensitive to it.

Omega-3 fatty acids. In a natural diet, dogs get omega-3 from prey that has itself eaten and converted plant sources into a form dogs can use. Omega-3 fats, especially the long-chain EPA and DHA found in oily fish, are among the most studied nutrients in canine health. They are recognised for their anti-inflammatory role and for supporting the brain, joints, skin and coat. But they are fragile. They degrade with heat and with exposure to air over time, and many everyday diets are naturally higher in omega-6 than omega-3, so the balance is often skewed before processing even begins.

Prebiotic fibre. Prebiotic fibres are the specific plant fibres that feed the beneficial bacteria living in your dog's gut. They are not the same as ordinary roughage. The microbiome is increasingly understood to be central to a dog's overall health, and good food should feed the microbiome as well as the dog. Prebiotic fibre helps support a healthy, resilient gut, and high-heat manufacturing can reduce the amount of intact prebiotic fibre that survives through to the finished food.

Antioxidant plant compounds. Normal body processes and everyday environmental exposure constantly generate free radicals, unstable molecules that can damage cells. Antioxidants are the counterweight: they help neutralise free radicals, which is why they are valued throughout the body. The natural antioxidant compounds in fruit and vegetables, such as the anthocyanins that give blueberries their deep colour, are sensitive to heat, so they tend to be diminished by the time a high-heat food is finished.

None of this makes kibble bad. It makes it cooked. Cooking is a trade-off, and these three nutrients happen to be on the losing side of it. Reviews of pet-food processing have documented how the heat of extrusion reduces heat-sensitive nutrients, which is what sits behind this point.

The gap if you feed kibble

In short: A quality kibble usually covers the basics, but the sensitive extras (omega-3, intact prebiotic fibre and antioxidants) can be under-delivered. You do not need to change the food, just add those specific things back.

If you feed a quality kibble, your dog is very likely getting the macronutrients and the vitamin and mineral minimums it needs. What can be under-delivered are the sensitive extras above: a meaningful level of EPA and DHA omega-3, intact prebiotic fibre, and plant antioxidants. The sensible response is not to rip up the diet that is working. It is to add back the specific things that high heat is hard on. That is a narrow, well-defined job, and it is exactly what a daily complementary supplement is for.

The gap if you feed raw

In short: Raw gets the protein right, but muscle-heavy bowls can be short on omega-3 balance and prebiotic plant fibre unless they are deliberately added. So raw has gaps too, just different ones.

Raw feeding gets a lot right. The protein is typically excellent and minimally processed, and there is no high-heat step stripping nutrients out. But raw has its own predictable gaps. Many raw bowls are muscle-meat heavy, which can leave the omega-6 to omega-3 ratio skewed unless oily fish is deliberately added. And the animal-based raw model is usually light on prebiotic plant fibre, which home raw feeding rarely replaces. So a raw-fed dog can be short on the same omega-3 balance and prebiotic fibre as a kibble-fed dog, just for different reasons. Feeding raw does not remove the supplement question. It reframes it.

What about fresh or home-cooked diets?

In short: Gentle cooking is kinder to nutrients than extrusion, but home recipes are hard to balance, so the same sensitive nutrients can still fall short. No single way of feeding automatically covers everything.

Fresh and home-cooked diets sit somewhere in between. Gentle cooking is kinder to nutrients than extrusion, but home recipes are notoriously hard to balance, and the same sensitive nutrients can still fall short unless the recipe is built carefully. The honest takeaway across all of these is the same: no single way of feeding automatically covers everything, and the gaps tend to cluster around the same few nutrients.

So, do dogs need supplements?

In short: Not every dog does. A dog on a varied, well-rounded diet may need very little. But for most dogs on everyday diets, a targeted daily supplement that adds back omega-3, prebiotic fibre and antioxidants is a reasonable, low-effort addition.

Here is the honest answer. Not every dog needs every supplement, and a dog on a genuinely well-rounded, varied diet may need very little. Supplementing for the sake of it is how people end up with a cupboard of half-used tubs and no idea which, if any, is doing something. The useful version of the question is narrower and far more practical: is your dog reliably getting enough of the nutrients that processing tends to strip out, and is there a simple, clean way to add them back if not?

For most dogs on most everyday diets, a short daily supplement that targets the predictable gaps, the omega-3 balance, prebiotic fibre and plant antioxidants, is a reasonable and low-effort addition. The key word is targeted. A supplement should be doing a specific, explainable job, not promising to fix everything at once.

What to look for in a daily supplement

In short: Look for a short, recognisable ingredient list, meaningful inclusion levels, a format that protects sensitive nutrients (such as freeze-drying), no fillers, and honesty about what the product is.

If you decide to add one, a few things separate a supplement that earns its place from one that does not.

A short, recognisable ingredient list. You should be able to read every ingredient and know roughly what it is doing. A long list of vague extras is usually a sign that quantity has been chosen over clarity.

Meaningful inclusion levels. An ingredient only does something if there is enough of it. Token amounts exist to be listed on a label, not to have an effect, so look for products that are open about how much of each ingredient is actually in there.

A format that preserves what it contains. If the whole point of a supplement is to deliver sensitive nutrients, it makes little sense to manufacture it with the same high heat that removed them in the first place. This is the logic behind freeze-drying, which removes moisture at low temperature rather than cooking at high heat, so more of the original nutrients are preserved.

No filler and nothing it does not need. Clean should mean clean. No artificial preservatives, no fillers, no padding to bulk out the tub.

Honesty about what it is. A daily supplement is a complement to a good diet, not a cure and not a replacement meal. Be wary of anything that talks like medicine or promises dramatic results on a timeline.

A quick word on marketing claims

In short: Be a sceptical reader. Trustworthy supplements describe what an ingredient is and what it supports, rather than promising to cure conditions or deliver results by a set week.

Pet wellness is a noisy category, and it is worth being a sceptical reader. Useful supplements describe what an ingredient is and what it supports. They do not promise to cure conditions or guarantee results by a certain week. If a product leans on big, specific health promises, ask what evidence sits behind them. Claiming less, and being able to back it, is usually the more trustworthy signal.

Where WYLDR fits

In short: WYLDR's Every Dog Every Day is a freeze-dried daily supplement with four clean ingredients (wild boar, salmon oil, chicory root and blueberry), made to add back what everyday diets tend to miss, alongside whatever your dog already eats.

WYLDR was built for exactly this job. Every Dog Every Day is a freeze-dried daily supplement with four clean ingredients and nothing else: a wild boar base, salmon oil, chicory root and blueberry. It is a complementary feed, designed to sit alongside whatever your dog already eats, whether that is kibble, wet food or raw.

The thinking is simple. Freeze-drying keeps in more of what high heat takes out. Chicory root is a source of prebiotic fibre. Blueberry brings natural antioxidants. The wild boar base is a lean, single novel protein that is gentle on sensitive tummies. That is the whole idea behind the line we keep coming back to: your dog's food is good, we add what's missing.

Frequently asked questions

Do dogs really need supplements if they eat complete food?
Not always. Complete food meets minimum requirements, but nutrients like omega-3, prebiotic fibre and antioxidants can be under-delivered. A targeted daily supplement adds those specific things back without changing the main diet. Recognise what's in your dog's food, and optimise what's missing.

Can I give a supplement to a raw-fed dog?
Yes. Raw diets are often light on prebiotic plant fibre and can have a skewed omega-3 balance unless oily fish is added, so the same gaps apply. A complementary supplement fits alongside a raw routine.

Is a supplement the same as a treat?
No. A treat is fed for reward. A daily supplement is fed for a nutritional reason and is meant to be given consistently. WYLDR is a natural daily supplement, not a treat.

How do I add a supplement to my dog's food?
Most daily supplements are simply added to the existing meal. Introduce anything new gradually over a few days so your dog can adjust.

Can puppies have a daily supplement?
Many daily supplements are suitable across life stages, but puppies have specific needs, so check the product guidance and speak to your vet if you are unsure.

Will a supplement upset my dog's stomach?
A clean, single-protein supplement with a short ingredient list is generally well tolerated, including by dogs with sensitive stomachs. Introduce it gradually. If your dog has a diagnosed health condition, speak to your vet first.

Sources

• "A literature review on vitamin retention during the extrusion of dry pet food" (ScienceDirect): link
• Today's Veterinary Practice, "Role of Dietary Fatty Acids in Dogs and Cats": link
• University of Guelph Pet Nutrition, "Prebiotics for dogs": link
• Regulation (EC) No 767/2009, Article 3 (legal definitions of "complete" and "complementary" feed): link
• "Oxidative stress, antioxidants, and assessment of oxidative stress in dogs and cats" (JAVMA): link