Intestinal microbiota in dogs and cats: restoring balance

Animal intestinal microbiota: understanding disorders before acting

The animal intestinal microbiota participates in digestive function

The animal intestinal microbiota is the set of micro-organisms present in the digestive tract. In dogs and cats, it interacts with diet, the mucosa and the immune defences. To support its balance, start by looking for the cause of the disorders and stabilising feeding habits. A supplement does not replace this work.

Are you wondering whether your animal's soft stools come from its intestinal flora? This is possible, but their appearance does not allow a diagnosis. Diarrhoea can also accompany a parasitosis, an intolerance or another illness. The term dysbiosis refers to a modification of the microbial ecosystem, not a diagnosis established in front of the bowl.

The aim is therefore not to choose a probiotic at random. The species, age, symptoms and treatments must be considered. The owner's observations then help the vet decide on the necessary examinations and support.

Animal intestinal microbiota: a balance specific to each individual

The composition of the microbiota varies between animals and over the course of their life. As a result, a universal list of "good bacteria" is not enough to explain all digestive disorders.

In dogs: consider the whole ration

Kibble is only part of the diet actually consumed. Treats, leftovers, stolen food and products given with tablets also count. A precise diary can therefore reveal a change that went unnoticed. Note the quantities as well as the brands.

An abrupt transition or an excess of food can accompany a change in stools. However, this succession does not prove that the microbiota alone explains the episode. If the disorders persist, avoid switching between foods in the hope of quickly finding the right one.

In cats: preserve food intake

Cats have specific nutritional needs. A recipe intended for dogs does not constitute a ration suited to cats. Likewise, successive additions can unbalance a complete food or discourage a fussy animal.

A marked drop in appetite deserves a prompt veterinary opinion. Do not wait for the end of a digestive course to report it. Weight, the amounts eaten and any vomiting provide more information than a general impression of "fragile flora".

Animal intestinal microbiota: possible causes and signs to watch for

Digestive disorders have multiple, sometimes combined, origins. Clinical examination allows them to be prioritised; a supplement does not allow them to be differentiated.

Circumstances to report

• A change of food, treats or meal schedule.
• A recent course of antibiotics or another treatment, with its name and dates.
• A period of stress, a trip or a stay in a group setting.
• Parasite exposure or an unusual ingestion.
• A known illness, weight loss or recurring disorders.

Antibiotics can alter microbial communities. This does not justify stopping a useful prescription. Contact the prescriber if the stools change during treatment; they will specify the appropriate course of action.

Signs that call for a consultation

Monitor the stools, but also the appetite, vomiting and activity. Bad breath or a dull coat do not identify dysbiosis. Avoid automatically attributing an intestinal origin to them.

Contact a vet promptly in case of blood, repeated vomiting, lethargy, pain or refusal to eat. A belly that suddenly swells is also a warning sign. In a young animal, a fragile animal or one that is already ill, seek advice as soon as the disorders begin. There is no need to wait for several signs or a 72-hour period.

Supporting the intestinal flora with a gradual approach

The first step is to treat the possible cause and secure the diet. Products acting on the microbiota can then complement an individual programme.

Adapting the diet without multiplying changes

Maintain a complete ration suited to the species, unless instructed otherwise by a veterinarian. Avoid fatty leftovers and improvised additions. Leave fresh water available. If the animal vomits or stops drinking, seek advice quickly.

When a dietary change is planned, introduce the new food gradually. The pace depends on tolerance and the reason for the change. A medical protocol may require a different organisation. Do not mechanically continue a transition if symptoms increase.

Monitoring becomes clearer when changes remain identifiable. Note the date of the new food, the supplement and any new treat. However, never delay a prescribed treatment in order to change only one parameter at a time.

Probiotics, prebiotics and postbiotics: reading the terms correctly

• Probiotic: live micro-organisms administered in adequate amounts, with a demonstrated benefit for the host concerned.
• Prebiotic: substrate selectively used by micro-organisms and associated with a benefit for the host. Not all fibres automatically meet this definition.
• Postbiotic: preparation of inactivated micro-organisms or their components, with an established benefit. The word does not refer to just any fermented extract.
• Symbiotic: combination of live micro-organisms and substrates used by micro-organisms. The interest concerns the formula evaluated.

These words describe categories. They do not allow products to be ranked from weakest to strongest. The strain, the formulation and the clinical situation matter. A result obtained in humans does not prove the same effect in dogs or cats.

What the studies allow us to conclude

A veterinary review published in 2024 describes encouraging but still variable results depending on the interventions. It does not allow us to promise that every probiotic corrects every diarrhoea. Improvement of stools and modification of the microbiota are also two distinct results.

In France, INRAE, MNHN and EnvA studies have examined a particular strain against Giardia. This research does not turn commercial supplements into antiparasitic treatments. It mainly illustrates the importance of precisely identifying the strain studied and its context of use.

If in doubt, consult your veterinarian before any treatment.

Choosing the duration and organisation with the professional

There is no universal duration for "rebuilding the flora". Follow the instructions of the chosen product and the advice received. A short or prolonged course only makes sense with an objective and a reassessment point.

If an antibiotic is prescribed, ask how to organise the doses. Do not decide alone on an interval applicable to all strains. Also report digestive dressings and other oral treatments: their combination may require specific precautions.

Finally, check the storage and the use-by date. A preparation containing live organisms requires its storage conditions to be respected. The ENVT's work on labelling highlights the importance of this viability, without allowing a current brand to be judged from old samples.

A useful notebook, without a diagnostic score

A notebook makes it possible to describe the progress without turning your observations into a diagnosis. Note down each day the food actually eaten, the stools, the vomiting and the behaviour. Add the treatments and recent changes.

• Date and time of digestive episodes.
• Appearance of stools, with a photograph if useful.
• Appetite and quantities consumed.
• Usual activity or unusual decrease.
• Products administered and times.

Pass this information on to the clinic when you call. This notebook does not measure the microbiota. A single worrying sign is enough to ask for advice; no score or minimum number of criteria should delay the consultation.

Comparing presentations suited to dogs and cats

The practical choice depends on the product recommended and how the animal takes its meals. The following examples allow you to compare the available presentations. They do not constitute a ranking of effectiveness.

FortiFlora Canine: sachets intended for dogs

The product sheet FortiFlora Canine, 30 sachets of 1 g presents a supplement for dogs. The sachet makes daily organisation easier once a use has been recommended. Check the instructions for the presentation received, without transposing those of another formula.

A powder format assumes that the animal actually consumes the food to which you add it. A bowl left untouched does not guarantee intake. In case of refusal, ask for a suitable solution rather than multiplying new foods.

FortiFlora Feline: a separate reference for cats

The presentation FortiFlora Feline, 30 sachets of 1 g concerns cats. Its separate identification avoids choosing a box solely based on its appearance. Any potential benefit must always match the disorder and the animal.

Respect feeding habits. If the addition puts the cat off its ration, contact the professional supporting you. Maintaining its food intake remains the priority; the supplement must not become an obstacle to the meal.

Canikur Pro: a paste presentation

The product sheet Canikur Pro, 60 ml syringe presents a paste for dogs and cats. This format allows a different way of organising administration. However, the graduations and conditions of use of the exact product must be respected.

The formula combines several types of ingredients. It is therefore not interchangeable with a simple powder on the sole criterion of "probiotic". Ask for advice before combining several supplements or digestive treatments.

Mistakes to avoid with probiotics for dogs and cats

The main mistake is to treat all disorders as a lack of beneficial bacteria. A consistent approach avoids repeated changes and keeps the cause of symptoms at the forefront.

• Do not give a human product without checking its composition and without veterinary advice.
• Do not equate yoghurt or kefir with a preparation evaluated in your animal.
• Do not combine products in hopes of a faster effect.
• Do not stop a prescribed treatment because a supplement seems more natural.
• Do not mask recurrences with repeated courses without a check-up.

A better-formed stool is a useful observation, but it does not prove the disappearance of a disease. Conversely, the absence of a rapid effect does not justify increasing the amounts on your own. The decision depends on overall progress and the agreed programme.

To go further

The section transit and digestion for dogs gathers different families of products. Their presence in the same category does not mean they have the same role. Compare the species, the presentation and the precautions before asking for advice.

Supporting the animal's intestinal microbiota daily

The animal's intestinal microbiota is part of a whole: diet, digestive health, environment and treatments. To support it, favour stable habits, precise observations and a response suited to the symptoms. Probiotics may have a place in this follow-up, without becoming an automatic response.

The most useful benchmark remains concrete: is your animal eating, keeping its activity level and progressing favourably? Any worsening calls for a reassessment. The notebook facilitates this discussion; it replaces neither the examination nor the veterinarian's instructions.

Sources

• ENVT — Jousse-Baudonnet, 2019: labelling of food for dogs and cats, notably the part on probiotics and their preservation.
• INRAE, MNHN and EnvA — research on a probiotic strain and Giardia, 2025. Results specific to the research described.
• INRAE — microbiota, history and mechanisms studied. General scientific context.
• Salavati Schmitz, 2024 — use of biotics in digestive disorders of dogs and cats. Scientific review in English.
• Salminen and collaborators, 2021 — scientific precision of the definition of postbiotics. Terminological reference in English.