Veterinary Medicines Safety Day highlights importance of reporting issues with antiparasitic medicines

Social media campaign encourages vets and animal owners to report when antiparasitic medicines don’t work as expected

Today is Veterinary Medicines Safety Day, the second annual social media campaign encouraging vets and animal owners to report adverse events for veterinary medicines. The campaign was developed by the European Medicines Agency (EMA) and the Federation of Veterinarians of Europe (FVE), and is supported by the HPRA along with other national medicines regulators across Europe.

In 2026, the campaign focuses on the importance of reporting cases where antiparasitic medicines do not work as expected. Throughout the day, on our  LinkedIn and Instagram accounts, we will encourage vets and animal owners to check whether antiparasitic treatments are effective and to report when they are not.

Reporting helps to protect animal and public health 

Antiparasitic medicines help protect animals from infections or diseases caused or transmitted by parasites such as worms, fleas, ticks, and mites. 

However, there are times when these medicines do not work as expected. This can happen for several reasons, including antiparasitic resistance, incorrect dosing or using the wrong product. 

When we receive reports that a medicine has not worked well, it helps us learn more about how to use antiparasitic medicines safely and effectively. We can take regulatory action when needed, such as updating guidance on how a product should be used or providing clearer information to vets and animal owners. Reporting helps to protect animal and public health. 

Checking if an antiparasitic medicine works as expected 

To help ensure these medicines work properly, it is important to follow the instructions provided by a vet and to read the package leaflet carefully.

Vets have an important role to play by only using antiparasitic medicines when necessary, selecting the correct dose and educating animal owners about how to use the treatment correctly. 

Vets and animal owners can look for signs that an antiparasitic medicine may not have worked well. These include:

• Ongoing signs of parasites 
• No improvement after treatment
• Weight loss or poor growth 

If an animal has not improved after finishing an antiparasitic treatment, speak to your vet and report the issue to us. You can also report if you suspect your animal experienced a side effect from the treatment. 

How to report

Anyone can report using our online form. We welcome reports from:

• Vets, veterinary nurses and pharmacists
• Animal owners, including farmers and pet owners
• Wholesalers and licensed retailers

Visit our webpage to learn more about reporting: Reporting a side effect | Information for vets and animal owners. This page includes a video with a clear practical overview of reporting side effects and other adverse events.