The complete guide to supplements for dogs and cats: when they are needed, which to choose and how to give them safely

Bemo is a brand that helps dog and cat owners every day to choose good food and take a sensible approach to supplements. This guide was written so that you can make an informed decision about whether your dog or cat really needs supplements, which products make sense and how to use them safely.

Supplements for dogs and cats – does your pet really need them?

Slogans such as "essential vitamins for every dog" or "a must-have for your cat's immunity" easily create the impression that supplements are always necessary for everyone. Yet current nutritional guidelines (including those from FEDIAF and WSAVA) are very clear:

if your dog or cat is healthy,
eats a complete (fully balanced) food,
suited to its age and health,

…then routine supplementation with vitamins and minerals is usually unnecessary[1][3].

Supplements make sense when:

there is a specific health reason (e.g. joint disease, digestive problems, chronic kidney disease),
the diet is non-standard (BARF, home cooking, alternative diets),
a vet, after an examination, decides it's worth supporting the body with, for example, omega-3 fatty acids, a probiotic or a liver supplement.

At Bemo, we don't treat supplements as "magic pills for everything", but as a sensible addition to a well-chosen food.

What are supplements for dogs and cats and how do they work?

Supplement vs medicine – an important difference

Supplements (complementary feeds) for animals are products that:

add specific nutrients to the diet (e.g. omega-3 fatty acids, vitamins, minerals, probiotics),
may not claim to "treat disease",
are governed by feed law (in the EU, among others, Regulation 767/2009)[35].

Veterinary medicines:

are used to treat and prevent disease,
must have proven efficacy and safety,
go through a rigorous approval process.

In practice:

a supplement can support treatment (e.g. omega-3 for joint disease),
but it will not replace medicines prescribed by a vet.

How do supplements work?

Depending on the type, they:

make up for deficiencies (e.g. mineral and vitamin mixes for a BARF diet),
modulate inflammation (omega-3, selected plant antioxidants),
influence the gut microbiota (probiotics, prebiotics),
support organ function (SAMe and silymarin for the liver, omega-3 fatty acids for the kidneys and heart),
influence behaviour (L-theanine, alpha-casozepine, L-tryptophan – support for anxiety and stress).

It's not just the ingredients that matter, but also the dose, form and quality of the product.

When do dogs and cats really need supplements?

Below are the situations in which vets most often consider supplementation.

1. Joint disease (especially in dogs, but also in cats)

large-breed dogs, seniors, animals recovering from injuries,
cats – OA (osteoarthritis) is very common but often goes unnoticed.

What may make sense:

omega-3 (EPA/DHA) – used alongside pain relief, they help reduce pain and improve quality of life[6][9],
possibly selected collagen products (although evidence of their effect is limited[10]).

Typical "joint" tablets with glucosamine and chondroitin have weak scientific backing – they shouldn't be treated as the main form of treatment[10].

2. Skin and coat problems, allergies

For atopic dermatitis or chronic skin problems, a vet may recommend:

omega-3 and omega-6,
products with zinc, biotin and vitamin E,
support for the skin barrier through diet and supplements.

For dogs with allergies or sensitive skin, it's also worth considering a good food for dogs with skin problems or food for allergic cats, so that the diet and supplements complement each other.

Supplements won't replace allergy testing or treatment, but they can noticeably improve the condition of the skin and coat.

3. Digestive disorders, sensitive stomach

For diarrhoea, after antibiotics or with IBS:

well-chosen probiotics (specific strains tested in dogs and cats),
prebiotics (e.g. FOS, MOS, inulin),
sometimes digestive enzymes.

Research shows that the right probiotic can shorten the duration of diarrhoea, improve stool quality and support gut immunity[11][13].

For these animals, foods for dogs with sensitive stomachs and foods for cats with digestive problems also work very well as the basis of the diet, with supplements as a precise addition.

4. Seniors – older dogs and cats

Older animals more often struggle with:

joint disease,
kidney and heart problems,
cognitive decline.

In such cases, a vet may recommend, among other things:

omega-3,
selected antioxidants (vitamins E and C, coenzyme Q10),
support for the liver, kidneys or heart.

Here it's especially important to match the diet and supplements to test results – something the Bemo team understands well when helping you choose a food for senior dogs or food for senior cats along with the right extras.

5. Puppies, kittens, pregnancy and lactation

With a good growth food or a diet for pregnant bitches and queens, extra multivitamins and calcium are usually not recommended. They can even do harm (e.g. excess calcium in large-breed puppies leads to bone problems)[29].
Supplements are considered when:
- a home-made/BARF diet is fed (it must be fully balanced),
- there are specific health problems.

If you're looking for a well-balanced food for large-breed puppies or food for kittens, at bemopets.com you'll find products suited to each stage of growth, which helps minimise the need for extra supplements.

6. Chronic diseases (kidneys, liver, heart)

Examples:

chronic kidney disease (CKD) – in addition to renal diets, omega-3 and phosphate binders are often used[19][20],
liver problems – supplements with SAMe and silymarin/silybin (milk thistle) support liver regeneration and improve biochemical parameters[21][22][23],
heart disease – for some dogs and cats, a vet prescribes taurine, L-carnitine and omega-3[7][24].

7. Anxiety, stress, hyperactivity

Supplements with L-theanine, alpha-casozepine or L-tryptophan can:

ease the symptoms of stress,
make behavioural therapy easier.

However, they won't replace work with a behaviourist or drug treatment when it's needed[14][15][16][17]. At bemopets.com you'll find both calming supplements for dogs and cats and "calm" foods that can be part of such therapy.

The main types of supplements for dogs and cats

Below is an overview of the most commonly used groups of supplements, in the form of a handy cheat sheet.

1. Omega-3 fatty acids (EPA/DHA)

Uses:

supporting the joints and reducing inflammation,
improving skin and coat condition,
supporting kidney and heart function,
supporting brain function, especially in seniors[9][18][19][25].

What to watch out for:

choose products that state the amount of EPA + DHA in mg per 1 kg / per capsule,
avoid accidental doubling up (omega-3 in the food + in treats + in supplements),
overdosing can cause diarrhoea, clotting problems and excess calories.

At bemopets.com you'll find salmon oils and omega-3 supplements for dogs and cats matched to your pet's body weight and needs, so it's easy to choose the right dose.

2. Vitamins and minerals

When do they make sense?

with home-made diets (BARF, cooked, vegan), balancing with mineral and vitamin mixes is essential,
with confirmed deficiencies (e.g. after blood tests),
in specific health conditions (e.g. anaemia, absorption problems).

What to avoid?

"just in case" multivitamins for a dog or cat on a good complete food – this can lead to vitamin D and A toxicity and excess calcium[26][27][28][29],
combining several products containing the same vitamins and minerals.

If you feed BARF or cook at home, it's worth using specialist vitamin and mineral mixes for dogs and cats, which help balance the diet in line with current nutritional knowledge.

3. Joint supplements

Typical ingredients:

glucosamine,
chondroitin,
MSM,
collagen,
sometimes added omega-3 and antioxidants.

What does the science say?

for most glucosamine + chondroitin combinations there is no strong evidence of a clear clinical effect[10],
some collagen products may bring moderate improvement, but they are more of a support than a breakthrough.

If you decide on such a supplement, choose products:

with a clearly stated dose in mg/kg,
from manufacturers that care about quality and research.

At bemopets.com you'll find a wide choice of joint supplements for dogs and cats that are easy to match to your pet's age, body weight and activity level.

4. Probiotics and prebiotics

Uses:

acute and chronic diarrhoea,
support after antibiotic treatment,
a sensitive digestive tract,
sometimes as part of immune support.

Important:

what counts is the specific strain (e.g. a particular Lactobacillus or Enterococcus) and its documented effect in dogs/cats[11][13],
look at:
- the full name of the strain (e.g. Lactobacillus rhamnosus GG),
- the number of CFU (bacteria) per dose,
- the manufacturer's recommendations.

At bemopets.com you'll easily find probiotics made for dogs and cats, rather than "universal" products for humans.

5. Skin and coat supplements

They generally combine:

omega-3 and omega-6 fatty acids,
zinc, biotin, vitamins A and E.

They help with:

a dry, dull coat,
dandruff and brittle hair,
recovery after skin conditions.

It's also worth choosing the right food for your dog's or cat's skin and coat, so the improvement is lasting and comprehensive.

6. Calming and anti-stress products

They most often contain:

L-theanine,
alpha-casozepine,
L-tryptophan,
herbal extracts (lemon balm, valerian),
sometimes melatonin.

They can help with:

separation anxiety,
noise sensitivity (storms, fireworks),
changes in the environment (moving house, a new family member).

Always treat them, however, as an addition to a therapy plan agreed with a behaviourist or vet. At bemopets.com you'll find both calming supplements for dogs and stress-reducing products for cats that can be part of such a plan.

7. Liver, kidney and heart support

Example ingredients:

liver – SAMe, silymarin/silybin, phospholipids,
kidneys – omega-3 fatty acids, B vitamins, phosphate binders,
heart – taurine, L-carnitine, coenzyme Q10, omega-3.

Use them only after a diagnosis and on your vet's recommendation, often together with a specialist food (e.g. renal or cardiac). At bemopets.com you can easily combine a veterinary diet with a suitable supplement supporting the organ your vet has indicated.

How to choose good supplements for your dog or cat?

When choosing a supplement, it's worth following a few simple rules.

1. A clear reason

Ask yourself:

what specific problem do I want to support (joints, skin, gut, kidneys)?
has it been diagnosed by a vet?
is my animal's diet complete and properly chosen?

If you're not sure, you can ask the Bemo team for advice on choosing food and supplements (e.g. by phone or email), describing your pet's age, breed, body weight and any health problems.

2. Ingredients and dose

Check the label for:

the exact amounts of active substances (e.g. mg of EPA + DHA, mg of taurine, CFU count of the probiotic),
the recommended dose per kg of body weight,
no unnecessary additives (sugars, artificial colours, flavourings, xylitol – which is toxic to dogs and cats).

3. Manufacturer and quality

Check whether the product:

comes from a reputable company,
has clear information about the manufacturer, a batch number and an expiry date,
is made in facilities that meet quality standards (HACCP, GMP+).

Specialist shops such as bemopets.com select their range with quality and safety in mind – a much safer option than random online purchases.

4. Transparent information

Good supplements have:

clear labels,
no exaggerated promises ("cures every disease"),
realistic descriptions of how they work and how to dose them.

How to give supplements to your dog or cat safely?

Rule 1: talk to your vet

Always discuss supplementation with your vet when:

your dog or cat has a chronic disease (kidneys, liver, heart, pancreas),
is on long-term medication,
is pregnant, nursing, or a puppy/kitten,
you plan to give more than one supplement at a time.

Rule 2: no human supplements

Don't give your animal supplements meant for humans unless your vet explicitly recommends it and works out the dose. Differences in composition (e.g. xylitol, other sweeteners, excessively high vitamin doses) can be dangerous[40].

Rule 3: watch the dose and body weight

dose according to body weight (mg/kg), not "by eye",
weigh your animal every few weeks – especially if it is undergoing treatment or a weight-loss programme.

Rule 4: not everything at once

avoid combining several supplements with similar ingredients (e.g. two multivitamins, several omega-3 products),
keep a simple log – what you give, at what dose and since when.

Rule 5: store them properly

keep fish oils cool and away from light,
don't use products past their expiry date,
store supplements out of reach of your dog or cat (helping themselves to the packet is a common cause of overdoses).

The most common mistakes in pet supplementation

"Just in case" for a healthy animal on a good food – with no medical reason.
Overlapping products – several products containing the same vitamin or mineral.
Human supplements given to animals without veterinary supervision.
Not telling the vet – the vet doesn't know the dog/cat is getting extra products.
Replacing treatment with supplements (e.g. treating heart or kidney disease "with herbs").
Not monitoring the dose and your pet's weight.
Buying cheap, anonymous products with no batch number, manufacturer or specific composition.

At Bemo, we put a strong emphasis on educating owners so they can avoid these mistakes – that's why you'll find reliable descriptions with our products, and if in doubt you can always ask us for details.

Supplements and diet: complete food, BARF, home cooking

An animal on a complete food (dry, wet, specialist)

If you choose a food that is:

labelled as "complete",
in line with FEDIAF guidelines,
suited to your pet's age (junior, adult, senior) and any health conditions,

…then its basic requirements for protein, fat, vitamins and minerals are covered[1][3].

In this case, supplements are mainly used:

for specific indications (omega-3, a probiotic, support for a particular organ),
after a diagnosis and on a vet's recommendation.

bemopets.com offers a wide choice of dry and wet food for dogs and cats, including specialist diets – so you can often improve your animal's health simply by choosing the right food, keeping extra supplements to a minimum.

An animal on BARF or a raw diet

Studies show that many home-made BARF recipes:

are deficient in minerals (Ca, Zn, Cu, iodine) and vitamins (D, E) and have an incorrect Ca:P ratio,
can cause bone disorders and other health problems[30][31][32].

That's why with BARF:

a professional recipe is essential,
you need to use complete mineral and vitamin mixes and the right amounts of oils,
supplementation is not an extra but the foundation of a properly balanced diet.

At bemopets.com you'll find ready-made BARF mixes as well as oils and mineral and vitamin supplements that help balance a raw diet.

An animal on a home-cooked diet

As with BARF, most "recipes from the internet" are significantly deficient[31][32].

If you want to feed your dog or cat home-made food:

have the recipe checked by a veterinary nutritionist,
use the supplement mixes recommended by the specialist, ideally dedicated supplements for home-made diets,
check blood test results regularly.

Alternative diets (vegan, vegetarian)

require intensive supplementation (taurine, vitamin B12, iron, zinc, vitamin D, etc.),
are particularly problematic and controversial for cats (obligate carnivores)[32].

Without close supervision by a vet and a nutritionist, they can lead to serious deficiencies.

How to plan supplementation with Bemo in practice – a simple plan

Assess the starting point
- Your dog's/cat's age, breed and body weight.
- Current food (brand, type, daily amount).
- Any diseases, medication or symptoms (e.g. diarrhoea, itching, stiffness after getting up).
Choose a good food as the base
- At bemopets.com, choose a food that is:
  - complete,
  - suited to the life stage (puppy, adult, senior),
  - tailored to any health problems (e.g. skin, digestion, kidneys).
Decide: is a supplement needed?
- If your pet is healthy and doing well, a good food is usually enough.
- If it has specific problems, decide together with your vet and choose from the supplements for dogs and cats at bemopets.com (omega-3, probiotics, support for the liver, skin and joints).
Choose a specific product
- Pick a product with:
  - clear ingredients,
  - a suitable form (capsules, oil, tasty tablets),
  - clear dosing instructions.
Monitor the results
- Look for improvements (e.g. coat, stools, ease of movement),
- note any changes in behaviour after introducing the supplement,
- after a few weeks, check test results if your vet has recommended it.

Checklist: how to prepare for a conversation with your vet about supplements

Before your vet appointment, prepare:

A list of all the food and treats your dog/cat gets (name, amount, frequency).
A list of the supplements currently given (name, dose, how long they've been used).
Information about medication (name, dose, frequency).
A short note about:
- symptoms that worry you (since when, how often, in what situations),
- changes in behaviour or appetite.
Questions you want to ask, e.g.:
- Does my dog/cat need extra vitamins/minerals with this food?
- Is it worth adding omega-3 / a probiotic / liver support given its current health?
- How long should the supplement be given, and when should we come back for a check-up?

With a checklist like this, it will be much easier for your vet to assess whether supplements make sense and which ones. You can then conveniently order them at bemopets.com, knowing that you're choosing a product in line with the specialist's recommendation.

FAQ: supplements for dogs and cats – frequently asked questions

Does a healthy dog or cat on a good food need supplements?

Usually not. A good-quality complete food covers nutritional requirements. Supplements are needed for specific indications (illness, home-made/BARF diets) or on a vet's recommendation[1][3].

If you're not sure whether the diet you're feeding is right, browse the food for dogs and cats at bemopets.com and then discuss supplementation with your vet.

Can I give my dog/cat an "immunity" supplement in autumn and winter?

There's no strong evidence that such products significantly reduce the number of infections in healthy animals. Much more important are a good diet, vaccinations, deworming and avoiding stress. If you want to add a probiotic or omega-3, talk to your vet.

Which supplements have proven effects for joint disease?

The best researched are omega-3 (EPA/DHA) as part of OA treatment. Products with glucosamine and chondroitin have weak evidence of efficacy – they can be considered as support, but they don't replace pain relief and physiotherapy[6][9][10].

At bemopets.com you'll find salmon oils and omega-3 products for the joints that you can easily add to your dog's or cat's diet as recommended by your vet.

Can I give my dog or cat a human probiotic?

It's best avoided. In dogs and cats, the effect of probiotics depends on the specific strain and dose, and products for humans aren't always suitable for animals[11][13]. It's safer to choose a probiotic made for dogs and cats – available at bemopets.com, for example, as a probiotic.

Can supplements do harm?

Yes. Examples:

overdosing on vitamin D and A,
excess calcium in growing large-breed dogs,
combining several supplements with the same ingredient,
using human products with toxic additives (e.g. xylitol).

That's why supplements should be taken as seriously as medicines – with care and ideally after consulting a specialist.

Will calming supplements solve separation anxiety?

No. They can ease the symptoms and help with training, but the key is working with a behaviourist and – for more severe problems – sometimes drug treatment too[14][15][16][17].

How long should a supplement be given?

It depends on the goal:

briefly for acute problems (e.g. a probiotic after antibiotics),
long term for chronic diseases (omega-3, liver or kidney support),
periodically, e.g. during increased exertion or recovery.

It's always worth agreeing a monitoring plan with your vet (blood tests, assessment of results).

Summary – smart supplements instead of random purchases

The key to your dog's and cat's health is a good, complete food and regular veterinary care.
Supplements are best seen as a tool for precisely supporting specific needs, not a "cure-all".
The best-documented effects come from omega-3, well-chosen probiotics and selected products supporting the liver and kidneys.
Not all popular supplements (e.g. classic "joint" tablets) have strong scientific evidence of efficacy.
Always remember safety: doses, interactions and product quality.

If you want to choose supplements for your dog or cat wisely, start by assessing the diet, talk to your vet, and then browse the range at bemopets.com. You'll find food and supplements chosen with animals' real needs in mind, not passing trends.

Sources

[1] FEDIAF Nutritional Guidelines 2024 – Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs: https://europeanpetfood.org/wp-content/uploads/2024/09/FEDIAF-Nutritional-Guidelines_2024.pdf
[3] WSAVA Global Nutrition Guidelines: https://wsava.org/global-guidelines/global-nutrition-guidelines/
[6] Cachon T. et al., COAST Development Group – International consensus guidelines for osteoarthritis in dogs (2023): https://scholars.cityu.edu.hk/files/173287136/162022269.pdf
[9] Carlisle C. et al., The Effects of Omega-3 Supplementation on the Omega-3 Index, Pain and Quality of Life in Dogs (2024): https://www.mdpi.com/2076-2615/14/21/3108
[10] Barbeau-Grégoire M. et al., A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and Feline Osteoarthritis: https://www.mdpi.com/1422-0067/23/18/10384
[11] ISAPP – Prebiotics and Probiotics for Pets (fact sheet): https://isappscience.org/resource/prebiotics-and-probiotics-for-pets/
[13] Sun J. et al., Application of Probiotics in Cats and Dogs: Benefits and Mechanisms (2025): https://pmc.ncbi.nlm.nih.gov/articles/PMC12568152/
[14] Fan Z. et al., Dietary Strategies for Relieving Stress in Pet Dogs and Cats (2023): https://pmc.ncbi.nlm.nih.gov/articles/PMC10045725/
[15] Araujo J.A. et al., ANXITANE tablets reduce fear of human beings in a laboratory model in dogs: https://www.sciencedirect.com/science/article/abs/pii/S1558787810000171
[16] Buckley L.A., Is Alpha-casozepine Efficacious at Reducing Anxiety in Dogs? Veterinary Evidence: https://veterinaryevidence.org/index.php/ve/article/download/67/174
[17] Landsberg G. et al., Therapeutic effects of an alpha-casozepine and L-tryptophan supplemented diet on fear and anxiety in the cat: https://pmc.ncbi.nlm.nih.gov/articles/PMC5505228/
[18] Blanchard G. et al., Nutrition and aging in dogs and cats: assessment and dietary strategies (2025): https://vetsci.org/DOIx.php?id=10.4142/jvs.25222
[19] Brown S.A. et al., Beneficial effects of chronic administration of dietary omega-3 fatty acids in dogs with renal disease: https://pubmed.ncbi.nlm.nih.gov/9605110/
[20] ISFM Guidelines on the diagnosis and management of feline chronic kidney disease: http://www.catspecialists.com.au/wp-content/uploads/2024/09/isfm-consensus-guidelines-on-the-diagnosis-and-management-of-feline-chronic-kidney-disease.pdf
[21] Tedesco D.E.A. et al., Use of Milk Thistle in Farm and Companion Animals: A Review (2023): https://pubmed.ncbi.nlm.nih.gov/36302565/
[22] Gogulski M. et al., Effects of silybin supplementation on nutrient digestibility, hematological and biochemical parameters in dogs (2021): https://link.springer.com/article/10.1186/s12917-021-02929-3
[23] Gogulski M., Dietary supplements containing silymarin as a supportive factor in the treatment of liver diseases in dogs (2020): http://www.medycynawet.edu.pl/images/stories/pdf/pdf2020/122020/2020126457.pdf
[24] Larsen J.A., The Role of Taurine in Cardiac Health in Dogs and Cats (2020): https://www.advancesinsmallanimalcare.com/article/S2666-450X(20)30015-8/abstract
[25] Vendramini T.H.A. et al., Exploring the efficacy and optimal dosages of omega-3 supplementation for companion animals: https://www.cambridge.org/core/journals/nutrition-research-reviews/article/exploring-the-efficacy-and-optimal-dosages-of-omega3-supplementation-for-companion-animals/118271BA20C2863CF770CB7960145015
[26] Vecchiato C.G. et al., Case Report: A Case Series Linked to Vitamin D Excess in Pet Food (cats): https://pmc.ncbi.nlm.nih.gov/articles/PMC8416511/
[27] Crossley V.J. et al., Vitamin D toxicity of dietary origin in cats fed a natural complementary pet food: https://bioone.org/journals/Journal-of-Feline-Medicine-and-Surgery-Open-Reports/volume-3/issue-2/2055116917743613/Vitamin-D-toxicity-of-dietary-origin-in-cats-fed-a/10.1177/2055116917743613.full
[28] Jewell D.E. et al., Increased dietary vitamin D was associated with hypercalcemia and adverse effects in dogs (2023): https://www.frontiersin.org/articles/10.3389/fvets.2023.1242851/full
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