Once a veterinary medicinal product has been marketed, user experiences of this product are monitored. By collecting these reports, more and more knowledge about the veterinary medicinal product becomes available. Based on this information, possible actions can be identified to prevent adverse reactions, or to deal with them more effectively, by including an extra warning in the package leaflet.  This is referred to as veterinary pharmacovigilance.

As a marketing authorisation holder, you are legally obliged to submit reports of adverse events to the medicinal product authorities. There are detailed instructions on what needs to be reported and how this should be done. You are also responsible for making Periodic Safety Update Reports (PSURs) which you must submit periodically or at the request of the authorisation authority.