Librela: Take III

The brouhaha brewing about Librela is intensifying. A December 16th letter, written by the FDA and addressed to veterinarians, expressed concerns that during the approval process, Zoetis, the manufacturer of this injectable canine arthritis medication, may have under-reported/misrepresented its adverse side effects.

Since then, I’ve heard from several of you about your Librela experiences with me. They’ve run the gamut from “amazing” to “devastating.”

Two days following the release of the FDA letter, my daughter received this notification from her veterinarian:

On Monday, December 16, the FDA shared some updates with veterinarians about Librela, a medication we’ve been using to help dogs with arthritis pain. The report included a summary of adverse events reported since Librela’s launch in the U.S., along with the FDA’s review of those cases.

This kind of follow-up is part of the FDA’s standard process for any newly approved product, ensuring we’re all up to date on how treatments are performing out in the real world. Their goal is to keep veterinarians like me informed so we can have open, transparent conversations with you, the pet parents, about the best options for your furry family members.

Librela, a medication that’s been a game-changer for dogs dealing with arthritis pain, is a monoclonal antibody therapy that targets excessive nerve growth factor (NGF) in arthritic joints to relieve pain. It’s been FDA-approved in the U.S. since May 2023 but has already helped millions of dogs in Europe since 2021. With tens of millions of doses given worldwide, adverse events remain incredibly rare—less than 0.1% globally (<10 per 10,000 treated animals).

Again, the FDA review of reported adverse events is part of this agency’s standard process following approval of any product in the US.

Unfortunately, recent media articles have sensationalized these findings, purposefully characterizing the report as a warning instead of the informational update that it is. These articles have emphasized numbers like 3,600 reported adverse events over 14 months without context. This certainly sounds alarming on the surface, but it is important to highlight the science over anecdote. While any unexpected issue with a beloved pet is distressing, these numbers represent a tiny fraction of the millions of doses administered. Some of the events attributed to Librela were very serious, however most of these side effects were relatively mild, resolved after stopping the medication, or were overshadowed by the positive impact of the drug.

Here in Austin, we know our pets are family, and many older dogs in our community face significant arthritis pain. Librela has become an important option for these cases, especially when other therapeutics fall short. However, it’s important to know that Librela is specifically designed and FDA approved to treat arthritis—not neurological conditions like degenerative myelopathy or intervertebral disc disease. Since our furry friends can’t tell us exactly where and how it hurts, diagnosing arthritis versus other issues can sometimes be tricky without advanced imaging like MRIs, which aren’t always practical for senior pups. That’s where our best clinical judgment comes in, and why it’s so important to keep an open dialogue with your vet.

When we look at the bigger picture, Librela’s benefits far outweigh its risks for the vast majority of dogs.

To put it in perspective, non-steroidal anti-inflammatory drugs (NSAIDs) are prescribed every day to dogs and cats, even though they can cause side effects including vomiting, diarrhea, loss of appetite, lethargy, and, in severe cases, ulcers, kidney or liver problems, or death. Some side effects, like worsening kidney function in pets with hidden disease or severe gastric ulceration, can be unpredictable. However, despite the undeniable (albeit small) potential for harm, the overwhelming likelihood of benefit when used appropriately gives us the confidence to prescribe this drug so often. Countless of our pets’ lives are the better for it.

Arthritis is an extremely common disease which, when left untreated, severely diminishes the quality of life of millions of dogs. Librela isn’t a miracle drug or magic, but it is a valuable tool for helping dogs live happier, more comfortable lives. If you notice any changes in your pet after starting Librela—or any medication—please let us know. We’ll work with you and report any concerns to ensure all pets benefit from safe and effective treatments.

Is it only me, or does this reek of, “Thou doth protest too much?”

In the meantime, a Facebook group called Librela Class Action & Support Group has jumped to 4,500 members.

Oy, attorneys are gonna have a field day with this one.

Your thoughts?

Happy holidays,

Dr. Nancy