Filariasis in dogs: diagnosis and prevention

Dirofilaria immitis and Dirofilaria repens affect different sites and have different implications. Testing and prevention must be planned according to risk.

Two forms that must be distinguished

The cardiopulmonary and subcutaneous forms are not intestinal parasitic diseases. Both involve mosquitoes in their life cycle, but their signs, diagnosis and clinical relevance differ.

Confusing the species and sites also makes prevention advice unreliable.

Testing and assessment

Time since exposure, geographical area, travel and previous treatments influence the choice and interpretation of tests. A suspicious result requires further veterinary investigation.

Management of a positive dog should not be reduced to an online protocol.

Risk-based prevention

The veterinarian defines the product and schedule by considering exposure and clinical status. Commercial rankings and automatic combinations are not published.

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.

• ESCCAP — GL5 - Vector-borne diseases in dogs and cats (accessed 24/07/2026)
• Union Product Database — Veterinary medicines authorised in the European Union (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.