9 Dec 2025
Richard Meeson called for more information while addressing what he described as “forgotten truths and false myths” about the disease in a congress session.
Allister Webb
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Image: Trsakaoe / Adobe Stock
More needs to be done to help vets “contextualise” treatment decisions linked to a controversial canine osteoarthritis drug, a leading clinician and academic has warned.
RVC professor Richard Meeson called for more information about Librela while addressing what he described as “forgotten truths and false myths” about the disease during a London Vet Show (LVS) presentation.
The treatment has been at the centre of both clinical and legal disputes during 2025 amid fears over potentially serious side effects.
The drug’s manufacturer, Zoetis, has consistently defended the treatment and staged its own osteoarthritis session as part of the show’s programme.
In a separate presentation at Excel London, Prof Meeson described Librela as “the biggest step change in therapeutic functions we’ve had for a very, very long time”.
But while he recognised it could have significant benefits for some dogs, he suggested the clinical effect was no greater than that seen from a non-steroidal treatment, as he argued newer treatments were not necessarily better than those they replaced. He also acknowledged incidents of what he called “quite unusual” side effects in some patients before telling delegates: “We need some more information.”
Prof Messon said: “We really need to know how quickly do these things occur and what the risk factors are in any individual patient. That way, we can contextualise the benefit of giving the treatment against the risk.”
Fears over the safety of Librela and its feline equivalent, Solensia, have also inspired campaigns seeking to have the products withdrawn from sale, even though Zoetis insists it remains “confident in the safety and efficacy” of both products.
But the company has now stepped up its defence of Librela by issuing a formal response to some of its strongest academic critics.
In analysis published in the journal Frontiers in Veterinary Science earlier this year, musculoskeletal adverse event reports were recorded nine times more frequently in dogs treated with Librela than with other drugs.
The paper, which was also the subject of intense debate at May’s Veterinary Osteoarthritis Congress, also argued there was a “strong suspicion of a causal association” between the drug and accelerated joint destruction in 19 individual cases.
Zoetis officials insisted they were not excluding the possibility of any adverse event in their response to the analysis, which has now been published by the same journal and was discussed at the company’s LVS session.
However, they argued that the cases presented lacked “biological similarity” and did not support the existence of a canine equivalent to rapidly progressive osteoarthritis in humans.
They also warned of data limitations, which they claimed rendered the original analysis “incomplete and invalid”.
Despite the ongoing scientific dispute, Prof Meeson said it was important for vets to be aware that “atypical, adverse events are possible” and for such cases to be reported to help improve broader understanding of the issue.
But while Zoetis continues to encourage the reporting of adverse event cases direct to itself, concerns have also been raised that limitations in the VMD’s reporting protocols, including the development of a new online portal, could mean the full extent of issues linked to the drug may never be known.
