23/05/2025
The integrity of adverse event reporting is crucial. A key finding from our recent research highlighted a serious concern: drug manufacturers have the ability to modify adverse event reports – including the diagnosis, severity, and outcome – without informing the healthcare professional who submitted the report.
Our study focused on musculoskeletal adverse events in dogs receiving Librela, and found a deeply troubling pattern: two-thirds of adverse event diagnoses chosen by Zoetis specified "arthritis" or associated clinical signs like "lameness" – signs of the very condition the drug is licensed to treat. This is highly relevant, as the FDA has already identified "lameness" as a statistically significant safety signal for Librela.
A key factor here is the limited terminology available in the Veterinary Dictionary for Drug Regulatory Activities (VeDDRA). Crucially, the term rapidly progressive osteoarthritis (RPOA), used by multiple specialists who submitted adverse event reports in our study, is not currently listed in VeDDRA. While Zoetis could have solved this problem by asking the European Medicines Agency to add RPOA to the dictionary, they have so far opted not to.
Even more concerningly, Zoetis has been reclassifying serious adverse event reports as "non-serious”, including multiple reports submitted by veterinary orthopaedic specialists. This is reflected in approximately half of reports of ligament ruptures, luxations (dislocations), limb collapse, and septic arthritis (a serious joint infection) being filed by Zoetis as "not serious”. They even filed one-third of fractures (broken bones) as "not serious" and claimed that several dogs diagnosed with bone cancer (a tragically malignant condition) had "recovered”.
This practice involves a drug manufacturer who has twice been cited by the FDA for producing false and misleading information about Librela (see comments). To safeguard vulnerable animals and allow their caregivers to make an informed choice, the public urgently needs Zoetis to stop making excuses and start being transparent and accountable.
Source: https://doi.org/10.3389/fvets.2025.1581490
