FOI release

FOI Number of adverse reactions for Librela against number of doses used

Published 19 August 2025

Request ATI1067

I am a practicing VS in Glos UK. This week I have had several clients expressing concerns over Librela following the release of a paper looking at rapidly progressing osteoarthritis (RPOA). Vizla owners appear esp concerned.

Zoetis suggested I contact yoursleves as they cannot release the information, but under the freedom of information act, I can request that you adise me as to the number of suspected adverse reactions for Librela against nos. Of doses used and in particular any cases of RPOA

Our reply

Librela is a veterinary medicinal product (VMP) used for alleviation of pain associated with osteoarthritis in dogs. There are five different strengths authorised in the United Kingdom: Librela 5 mg Solution for Injection for Dogs, Librela 10 mg Solution for Injection for Dogs, Librela 15 mg Solution for Injection for Dogs, Librela 20 mg Solution for Injection for Dogs and Librela 30 mg Solution for Injection for Dogs.

Please be aware that the data we have provided below are not subject to independent verification and the Veterinary Medicines Directorate (VMD) does not guarantee their accuracy.

We have included all adverse event reports. This includes reports where more than one product was used, reports when the product was used off-label, that is using a medicine in a way that is not specified on the product’s label, or reports where, on further evaluation, there may have been other reasons for the adverse event occurring.

Evaluation is dependent on the accuracy and quality of data received from veterinary professionals and animal owners, and reporting frequency can vary over time (reporting frequency may be affected by a product being new to the market or social media interest, for example).

You requested “the number of suspected adverse reactions for Librela against number of doses used”. We can provide the reaction incidence, which is where the number of animals experiencing a suspected adverse event is divided by the estimated number of animals treated. The estimated number of animals treated is calculated from the number of doses sold by dividing the number of doses sold by the estimated average number of doses used per animal. For Librela, the figure we have previously used for the estimated average number of doses used per animal is 1. The resulting incidence has been rounded to 4 decimal places. The latest incidence of adverse events for Librela is 0.0015. This means that according to the data the VMD has received, fewer than 15 animals have experienced a suspected adverse event for every 10,000 doses of Librela used. This calculation does not consider any doses sold that were not used, for example doses discarded prior to administration.

The term ‘rapidly progressive osteoarthritis’ is not yet a recognised term in the veterinary field. It has been borrowed from human medical terminology. It has not been possible for the clinical signs reported to be ‘coded’ in a consistent manner using the terms available. It may have been coded as a ‘bone & joint disorder NOS’ or even ‘uncoded sign’, which would not specifically identify those cases relating to rapidly progressive osteoarthritis, without the full content of the narrative being assessed. Therefore, it is not currently possible to provide a definitive number of cases reporting this type of disorder.

However, a search of case narratives in our adverse event report database that contain ‘RPOA’, or ‘rapidly progressive osteoarthritis’, or ‘progressive osteo…’ identifies 37 such cases.