A Look at Librela

Librela is the newest osteoarthritis treatment in the US and of course, everyone is excited about a once monthly treatment to treat your dog’s pain. It can be extremely effective when used appropriately. However, in addition to the benefits, we are also seeing some concerning trends with the use of this drug and want you to be aware of the potential risks before pursuing it for your dog.

What is Librela (bedinvetmab)?

Librela is a monthly canine monoclonal antibody injection that must only be administered by your veterinarian and may take up to 6 weeks for observable results. A monoclonal antibody is a biological agent, a medical product that is isolated from a living creature rather than a chemical, that has been engineered to bind to a single target. Examples of biological agents include gene therapy, vaccines, and blood components.¹ Librela targets Nerve Growth Factor (NGF) to help reduce pain caused by Osteoarthritis. NGF is necessary for neurological development and maintenance though as an animal matures, it becomes part of the body’s sensation of and response to pain. NGF also contributes to healing and cardiovascular health.

Librela works by stopping the healing, growth, or maintenance of nerve tissues in the body. The dog’s pain stops when the nerves don't work and can no longer send pain signals to the brain. 

What Librela Can’t Do

It does not cure osteoarthritis.

While it can lessen the sensation of pain caused by osteoarthritis, it does not stop the inflammation and physical damage that is present and occurring within the joint.

In fact, we frequently see dogs that feel so much better on Librela that they return to more intense activity which then contributes to accelerated osteoarthritis formation. To learn more, check out our article Crunchy Doggos: Managing Osteoarthritis.

It should not be used to address any other conditions. This includes chronic or post-operative pain, like that associated with Cranial Cruciate Ligament (CCL/ACL) rupture or Tibial Plateau Leveling Osteotomy (TPLO). It cannot help those conditions and should not replace conventional methods of pain relief in those cases.

It should not be used in any case where nerve growth is required such as dogs that are breeding (including males), pregnant, or lactating. It should not be used in dogs that are physically immature and still growing. Keep in mind that many large or giant breed dogs do not reach physical maturity until 2-3 years of age.

Neurological Side Effects

Because Librela targets Nerve Growth Factor, it typically results in poorer nerve tissue health. The veterinary community is becoming increasingly aware of neurological adverse side effects associated with Librela including:

• Generalized weakness

• Inability to control bladder and/or bowels

• Stumbling

• Knuckling

• Dragging paws

• Inability to walk

• Seizures

In many cases, a dog may have had very mild neurological dysfunction that had gone unnoticed by their family until they were given Librela. That neurological dysfunction can worsen as soon as hours to weeks after a dose of Librela. 

Should your pet experience any of these symptoms, Librela should not be given again until your pet has been evaluated by a Veterinary Neurologist. It may take up to 3 months for a patient to recover from a Librela-induced neurological decline although patients with Degenerative Myelopathy are extremely unlikely to regain any lost ability. 

If your dog has any sort of neurological condition, such as Intervertebral Disc Disease, Degenerative Myelopathy, or Geriatric Onset Laryngeal Paralysis & Polyneuropathy, they should not be given Librela as it is likely to worsen their symptoms.

Autoimmune Side Effects

There are anecdotal reports of Librela worsening autoimmune conditions. This is especially concerning when it comes to conditions like Immune Mediated Polyarthritis (IMPA). Dogs with IMPA can present identically to dogs with “normal” osteoarthritis/degenerative joint disease but require very different treatment. For example, dogs with osteoarthritis are commonly prescribed NSAIDs like Rimadyl to address their pain, but dogs with IMPA require immunosuppressant drugs to control their pain. If a dog goes to the vet for pain, stiffness, or limping and thorough diagnostics are skipped in favor of jumping straight to medication, a dog with undiagnosed IMPA might be given Librela, then experience an increase in pain and inflammation.

Autoimmune side effects are still being discovered, so we recommend that dogs with any autoimmune conditions should not be given Librela.

Unknown & Long Term Safety Concerns

Safety and efficacy studies on Librela were only 84 days long (less than 3 months!) and were performed on young dogs free from other health conditions. Consider that senior dogs struggling with arthritis pain are the most likely patients to receive Librela and are also nearly guaranteed to have other conditions that may be complicated by Librela. 

There are no long term safety studies.

We are discovering long term side effects only after Librela was approved for widespread use in the US. It is not known what will happen to dogs that are on Librela long term.

A 2025 study published in Frontiers in Veterinary Science found that “Ligament/tendon injuries, polyarthritis, fractures, musculoskeletal neoplasia, and septic arthritis were reported nine times more frequently in Librela-treated dogs”.²

The same study compared Librela’s reports of adverse effects between November 2020 (its european release) and 2024 against a 20 year period for other, better established drugs. Most shockingly, Librela accumulated 3 times more reports of adverse effects than all comparator drugs combined.

“Librela has accumulated 20 times more reports [of adverse effects] than the highest-ranking comparator drug (Rimadyl)”.

NGF Inhibitor Treatments in Humans

Monoclonal antibodies are used in human medicine for many different applications, but development of those that target NGF in humans were halted by the FDA from 2010-2012 due to significant reports of Rapid Progression Osteoarthritis (RPOA) and Osteonecrosis (bone death).

“RPOA is characterized by an accelerated deterioration of joint structures, leading to severe pain and functional impairment."³

Incidence and severity increased the longer a patient was on an NGF inhibiting treatment, but some patients developed symptoms after only one dose. The concurrent use of NSAIDs like Advil or Aleve, the most common treatment for OA, may have also been a contributing factor.

Research and development later resumed, but RPOA and adverse neurological side effects have continually been observed in studies on multiple variations of human NGF inhibiting treatment.

In 2021, the FDA rejected Pfizer’s human NGF inhibitor tanzumab because there was no evidence that it was more effective than traditional painkillers like Ibuprofen and it posed too great a risk for RPOA.⁴

Teva & Regeneron’s fasinumab is currently in development and a December 2024 study still shows an increased risk for neurological and musculoskeletal adverse effects that increased with higher dosage.⁵

As of August 2025, Librela is being further investigated due to case reports of Rapid Progression Osteoarthritis (RPOA) in dogs given Librela. As of September 2025, there are no NGF inhibiting treatments approved for use in humans.

How to Use Librela as Safely as Possible

Try Other Treatments First

Studies have shown that NSAIDs are equally effective at treating osteoarthritis pain when compared to Librela. All medications have some level of risk but at least NSAID related side effects are well documented and can be reduced if your dog’s bloodwork is checked on a regular basis, which is recommended for all senior dogs anyway.

Commonly used NSAIDs include Rimadyl (carprofen), Metacam (meloxicam), and Galliprant (grapiprant). Some patients respond better to one than the other, so be prepared to potentially switch to a different NSAID if your dog doesn’t tolerate the first one you try. Other non-NSAID medications, like Gabapentin or Adequan, are also good, well-established options. Read our Pain Meds & Supplements article to learn more about commonly used medications.

Physical Rehabilitation

Rehab is recommended with or without Librela! A prescribed Rehab treatment plan may even be enough to avoid using Librela all together.

Dogs on Librela still need the other aspects of their osteoarthritis attended to including weight management and safe exercise.

Weight management is the most impactful aspect of treating osteoarthritis. CROC’s treatment plans include an evaluation of your dog’s diet to make sure all nutritional requirements are met while optimizing weight and muscle mass. Safe exercises, like those prescribed by CROC’s medical team, will help improve musculature that is integral for supporting your dog’s joints and preserve range of motion, all of which helps your dog remain comfortably mobile. 

Don’t Skip Diagnostics!

Electing to give your pet Librela without prior diagnostic screening is a big gamble! Due to potentially severe side-effects, we recommend that your pet be thoroughly evaluated to rule out auto-immune and neurological conditions before starting Librela.

This should include a nose-to-tail physical exam, bloodwork (chemistry + complete blood count) and radiographs at a minimum.

Depending on the results of those initial diagnostics, your dog may require evaluation with a neurological or orthopedic specialist instead of Librela.

To Summarize

While Librela can be a very effective method of pain relief, it is not well studied and serious side effects are still being discovered.

Studies show that well established drugs like Rimadyl or Metacam are equally effective at treating pain and have fewer reports of adverse effects.

Librela doesn’t treat inflammation or the physical damage that occurs within the joint, so it should not be used as the only treatment for your dog’s osteoarthritis. Weight management and safe exercise are still integral to your dog’s comfort and mobility.

Dogs with neurological or autoimmune conditions should never be given Librela.

Dogs that are breeding (even males), pregnant, lactating, or still growing should not be given Librela.

The FDA has not approved any human equivalents to Librela because the risk of patients developing Rapid Progression Osteoarthritis (RPOA) was too great. RPOA is being reported in Librela patients now.

Librela should not be a first line treatment and before starting Librela, your dog should be thoroughly evaluated and have comprehensive bloodwork and x-rays performed. 

References

1. Enomoto, M., Mantyh, P.W., Murrell, J., Innes, J.F., Lascelles, B.D.X., (2019). Anti-nerve growth factor monoclonal antibodies for the control of pain in dogs and cats. Veterinary Record of the British Veterinary Association. https://bvajournals.onlinelibrary.wiley.com/doi/10.1136/vr.104590

2. Farrel, M., Waibel, F.W.A., Carrera, I., Spattini, G., Clark, L., Adams, R.J., Von Pfeil, D.J.F., De Sousa, R.J.R., Villagra, D.B., Amegual-Vila, M., Paviotti, A., Quinn, R., Harper, J., Clarke, S.P., Jordan, C.J., Hamilton, M., Moores, A.P., & Greene, M.I. (2025). Musculoskeletal adverse events in dogs receiving bedinvetmab (Librela). Frontiers of Veterinary Science, volume 12. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1581490/full

3. Mobasheri, A., Hanson, P., Larkin, J., (2025). Rapidly progressive osteoarthritis (RPOA) in companion animals treated with bedinvetmab (Librela™): an expected pathophysiological phenomenon or a cause for concern?. Frontiers of Veterinary Science, Volume 12 - 2025. https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1640217/full

4. Jimenez, D., (2021). FDA panel votes against Pfizer’s tanezumab for osteoarthritis pain. Pharmaceutical Technology. https://www.pharmaceutical-technology.com/news/fda-pfizer-tanezumab-safety/

5. DiMartino, S.J., Mei, J., Schnitzer, T.J., Gao, H., Eng, S., Winslow, C., Ho, T., Turner, K.C., Hassan, H.E., Patel, Y., Davis, J.D., Trinh, N., Manley, A., Manvelian, G., Fetell, M., Braunstein, N., Geba, G.P., Dakin, P., (2024). A phase III study to evaluate the long-term safety and efficacy of fasinumab in patients with pain due to osteoarthritis of the knee or hip. Osteoarthritis and Cartilage Open, volume 6, issue 4. https://www.sciencedirect.com/science/article/pii/S2665913124001006

6. Bimonte, S., Cascella, M., Forte, C.A., Esposito, G., Cuomo, A., (2021). The Role of Anti-Nerve Growth Factor Monoclonal Antibodies in the Control of Chronic Cancer and Non-Cancer Pain. National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/34234542/

7. Dakin, P., DiMartino, S.J., Gao, H., Maloney, J., Kivits, A.J., Schnitzer, T.J., Stahl, N., Yancopoulos, G.D., Geba, G.P., (2019). The Efficacy, Tolerability, and Joint Safety of Fasinumab in Osteoarthritis Pain: A Phase IIb/III Double‐Blind, Placebo‐Controlled, Randomized Clinical Trial. National Library of Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC6900077/