The immune system in dogs and cats: what we know

The immune system is complex and is not automatically boosted by a single supplement. Vaccination, nutrition and disease management have distinct roles.

How immunity works

Innate defences and the acquired immune response work together against different agents. Age, disease, medicines and nutritional status can affect the response, but there is no single indicator of strong or weak immunity.

Maternal antibodies and the response to vaccines require schedules based on guidelines and individual risk.

Nutrition and supplements

A complete, appropriate diet is the nutritional foundation. Supplements should not be presented as preventing or treating infections without specific evidence and a professional assessment.

Different products may have different compositions, label indications and interactions.

When further investigation is needed

Recurring infections, weight loss, fever or persistent tiredness require examination and diagnosis; they should not be managed by independently increasing products or supplements.

Sources and document updates

This information is general and does not replace diagnosis, prescription or instructions from a veterinarian. For a medicine, the summary of product characteristics or package leaflet for the specific presentation is authoritative.

• WSAVA — Global vaccination guidelines (accessed 24/07/2026)
• WSAVA — Global nutrition guidelines (accessed 24/07/2026)

Editorial transparency: sources are provided to allow the documents to be checked. Professional review is only declared after genuine approval by a qualified, identifiable person.