Is Librela safe for your dog?

Musculoskeletal adverse events in dogs receiving bedinvetmab (Librela). Farrel et al., 2025.

Hello, and welcome to this in-depth explanation of the above study. The aim of this post is to provide dog owners with a better understanding of the risks associated with the use of Librela so that you can make the best decision for your dog.

So, let’s get started.

It’s no secret that osteoarthritis (OA) is the most common chronic pain condition in dogs, and it can significantly reduce their quality of life. Managing chronic pain is challenging because we have to consider the safety of potential long-term use of certain medications and how effective that medication is going to be for the individual.

Librela is a monoclonal antibody targeting nerve growth factor. But what does this mean?

Nerve Growth Factor (NGF) – a protein involved in nerve growth and maintenance, and is also implicated in pain perception.

Monoclonal Antibodies (mAbs) - man-made antibodies that are designed to specifically target and bind to NGF, to prevent it from interacting with its’ receptors.

Put it all together – Librela works by blocking NGFs from binding with its’ receptors, therefore disrupting the pain signalling pathway and reducing the perception of pain.

Use of mAbs in veterinary treatment of osteoarthritis passed regulatory approval in November 2020. Interestingly, the human equivalent were associated with substantial safety concerns including accelerated joint degeneration in humans.

As clinical trials cannot possibly capture a full spectrum of potential adverse reactions, adverse event reports are maintained and monitored for medications to ensure the safety of their use.

In December 2024, an open letter to vets was issued by the FDA, informing them of neurological and musculoskeletal adverse events associated with the use of Librela. The FDA’s analysis identified 18 distinct safety concerns in dogs treated with Librela, including neurological events, urinary problems, and musculoskeletal disorders. The FDA also observed a disproportionately high rate of “lameness” being reported in Librela-treated dogs.

The Investigation.

The study used a retrospective, case series design – whereby possible cases were identified by vets treating these individuals after an adverse event was noted. The first case was identified by one of the authors of the study, suspecting rapid progression osteoarthritis (RPOA) in a dog receiving Librela. That case was shared on a specialist veterinary forum, and over a period of 11 months several other vets shared their concerns over serious MSAEs in dogs treated with Librela.

To investigate this, a panel of 18 surgical specialists individually reviewed the musculoskeletal adverse event reports (MSAER) of Librela, Rimadyl, Metacam, Previcox, Onsior, Galliprant, and Daxocox. They hypothesised that Librela’s MSAER rate would not exceed that of six comparator drugs by more than 50%.

This diagram shows the protocol for reporting and monitoring Adverse Event Reports (AER). 86% of reports were made by vets, 12% by pet owners and 2% by other health-care professionals. These reports are sent to the Manufacturer (Zoetis) and Regulatory Authority.

The Results.

Tendon or ligament injuries, polyarthritis – arthritis affecting 5 or more joints – musculoskeletal neoplasia – tumours of the musculoskeletal system – and septic arthritis were reported approximately NINE times more often in Librela-treated dogs than the COMBINED total of dogs treated with the 6 comparator drugs.

Accumulated MSAERs comparing Librela to six comparator drugs. focusing on specific reaction types. No relevant MSAERs were found for Daxocox, a weekly NSAID released in April 2021, 2 months after Librela’s European launch.

Additionally, the accumulated MSAER rate for Librela over a 45 month period exceed the equivalent rate for the highest-ranking comparator (Rimadyl) by approximately 20 times.

The Cases.

 Case 1: An 8 Y/O Labrador Retriever with no history of trauma.

(A,B): Pre-treatment x-rays taken aged 8.5 years. (C,D): Post-Librela images showing a fracture to the lateral humeral condyle (C) and a humeral intracondylar fissure (D). (E,F) Immediate post-op x-rays following surgery to correct the fractures/fissures.

Case 2: A 7.5 Y/O Labrador Retriever.

Left: Normal pre-treatment CT scans. Right: Post-Librela CT scans showing the rapid and severe formation of bone spurs (fulminant periarticular osteophytosis) around the joints.

Case 3: A Staffordshire Bull Terrier with no history of trauma.

(A-D): Pre-treatment CT scans showing mild elbow arthrosis. E-H: Post-Librela x-rays shoeing sever left elbow arthrosis and a right lateral humeral condyle fracture.

Case 4: An 8 Y/O English Bull Terrier treated with Librela for elbow dysplasia.

This individual developed swollen hocks and hindlimb lameness within 3 weeks of the first dose of Librela. (A,B): X-rays taken after 2 Librela injections showing moderate arthrosis in both hocks, which rapidly progressed into dislocation of the hock joint (C-E).

Case 5: A 10.5 Y/O Mixed-Breed Dog treated with Librela following TPLO surgery (a surgery to correct luxating patella).

This dog had 7 Librela injections following TPLO surgery. The arrows highlight severe joint erosion causing the failure at the surgical site. Unfortunately, this dog had to be euthanised due to unmanageable pain.

Things to consider.

I am not a vet. I cannot diagnose or prescribe treatments for your dog. I am qualified canine professional that is a bit of a nerd and enjoys reading new studies – weird, I know!

There has been scepticism about Librela within the canine therapist community for some time, and I believe this study provides an incredible important insight into the safety of using Librela.

Personally, I don’t think long-term Librela treatment is a good idea. If you’ve got a younger dog suffering from OA, perhaps consider conservative management strategies initially such as weight and exercise management, hydrotherapy, massage therapy, red light or laser therapies, and the use of NSAIDs. However, if you’ve got an older dog that you want to enjoy a few good, pain-free months and other pain medications aren’t appropriate – maybe Librela is the way to go.

Ultimately, the best thing you can do for your dog is to have an open conversation with your vet, take the time to consider your options and make a decision based on what you feel is the best option for your dog.

Charis

Train & Treat

Further Information

Charis Donnelly, Train & Treat, is a qualified and experienced Canine Behaviourist & Massage Therapist providing treatments to prioritise your dog’s mental and physical wellbeing.

Charis is a member of the International Association of Animal Therapists which promotes best practice.

For more information on how massage therapy can help your dog, including those suffering from OA, email charis@train-and-treat.co.uk