General information on adverse reaction/event reporting

An adverse reaction: 

  • Occurs after the use of a veterinary medicine.
  • Is a harmful and unintended (or unexpected) event.
  • Is classified as either ‘serious’ or ‘non-serious’, depending on the clinical outcome.
  • May relate to any of the following:
  1. Reactions in the treated animal following recommended use of the product.
  2. Reactions in the treated animal when a veterinary medicine has not been used as recommended (so-called ‘off-label’ use).
  3. The product did not work as intended (lack of expected efficacy).
  4. Effects in humans following exposure to a veterinary medicine.
  5. Finding residues of a veterinary medicine in produce (e.g. meat, milk, honey) from a treated animal that exceeds permitted limits.
  6. Effects on the environment.

Adverse reactions should be reported either directly to the marketing authorisation holder or to the HPRA using the HPRA’s online reporting form, or pre-addressed HPRA reporting forms.

Reactions are considered to be serious if they are:

  • Fatal. 
  • Life-threatening. 
  • Disabling. 
  • Incapacitating. 
  • Permanent or result in prolonged symptoms in the animal treated. 
  • A human adverse reaction to a veterinary medicine.

Why report an adverse reaction/event?

Extensive testing is carried out on the safety and effectiveness of veterinary medicines before they are authorised for sale.  These studies can identify some common adverse reactions that an animal or a user may experience during or after treatment with the medicine.

However, certain interactions as well as rare adverse reactions or reactions specific to certain breeds or groups of animals may only be identified when the product is used more widely. It is therefore important that all suspected adverse reactions or events are reported to us to enable us to monitor the unexpected reactions and to take action where necessary.

Who should report?

  • Marketing authorisation holders (within 15 days if serious).
  • Veterinary practitioner or a pharmacist*.
  • Wholesalers*.
  • Licensed retailers*.
  • Members of the public (the advice of a vet should be sought if possible).
  • How to report an adverse reaction/event to the HPRA

    Report a suspected adverse reaction/event directly by filling in the online form.

    A downloadable version of the form is also available, which can be filled in manually and sent to the HPRA by e-mail or by freepost.

    A short video presentation providing a step-by-step guide on how to complete the online form is available below.

    A full transcript of this video is also available to download.

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    If you require further information about reporting an adverse reaction/event you can also contact the HPRA’s Veterinary Sciences Department on (01) 676 4971 or by emailing