Librela (bedinvetmab) is a prescription injectable medication manufactured by Zoetis for the control of pain associated with osteoarthritis (OA) in dogs. Approved by the FDA in May 2023, Librela is the first monoclonal antibody the FDA approved for use in dogs. It works by targeting nerve growth factor (NGF), a protein involved in pain signaling, and is administered as a once-monthly injection at your veterinary clinic. Librela represents a fundamentally different approach to OA pain management compared to traditional NSAIDs and has been used in over one million dogs in the United States, with more than 18 million doses distributed globally.
Because Librela is a biologic therapy rather than a traditional pharmaceutical, it works through a distinct mechanism that does not involve the liver or kidneys for metabolism, which has made it an option for dogs that cannot tolerate NSAIDs. However, as with all medications, Librela carries risks that should be discussed with your veterinarian, including neurologic adverse events that were added to the product label in February 2025.
What Is Librela Used For?
Librela is indicated for the control of pain associated with osteoarthritis in dogs. Your veterinarian may recommend Librela in situations such as:
- Moderate to severe osteoarthritis pain where ongoing pain management is needed
- Dogs that cannot tolerate NSAIDs due to kidney disease, liver disease, GI sensitivity, or other contraindications
- As part of a multimodal pain management plan alongside weight management, physical rehabilitation, joint supplements, and other treatments
- Dogs where daily oral medication is difficult to administer consistently
Librela is not a cure for osteoarthritis. It controls pain to improve quality of life and mobility. Osteoarthritis management typically involves multiple approaches, and your veterinarian will develop a comprehensive plan for your dog.
How Does Librela Work?
Librela is a caninized monoclonal antibody, meaning it is an engineered protein designed to closely match a dog’s own immune proteins. It specifically targets and neutralizes nerve growth factor (NGF), a key protein in the pain signaling pathway.
In osteoarthritis, damaged joint tissues produce elevated levels of NGF, which sensitizes pain nerves and amplifies pain signals. By binding to and neutralizing NGF before it can activate pain receptors, Librela reduces the pain signal at its source. This mechanism is entirely different from NSAIDs (which block prostaglandin production) and from other biologics like Cytopoint (which targets the itch-signaling protein IL-31).
Because Librela is a protein-based biologic, it is broken down by the body’s normal protein recycling processes rather than being metabolized by the liver or excreted by the kidneys. This is one reason it has been considered for dogs with organ impairment, though veterinary oversight remains essential.
Dosage & Administration
Librela is administered as a subcutaneous (under the skin) injection by your veterinarian once monthly. It is not a medication you give at home.
| Dog’s Weight | Dose | Injection Volume |
|---|---|---|
| 3.3 - 11 lbs (1.5 - 5 kg) | 5 mg | 0.25 mL |
| 11.1 - 22 lbs (5.1 - 10 kg) | 10 mg | 0.5 mL |
| 22.1 - 44 lbs (10.1 - 20 kg) | 20 mg | 0.5 mL |
| 44.1 - 99 lbs (20.1 - 45 kg) | 30 mg | 0.75 mL |
| Over 99 lbs (over 45 kg) | Weight-based combination | As directed by vet |
Your veterinarian will determine the correct dose based on your dog’s weight and may adjust the treatment plan based on your dog’s response. Effects typically become noticeable within the first week after injection for many dogs, though individual response varies. Monthly appointments are needed to continue treatment.
Important Safety Update: February 2025 Label Change
On February 18, 2025, the FDA updated Librela’s labeling to include additional adverse event information based on post-market surveillance reports. This is an important update that pet owners should be aware of and discuss with their veterinarian.
What was added to the label:
- Neurologic adverse events have been reported in dogs receiving Librela, including ataxia (unsteady gait/loss of coordination), seizures, paresis (partial paralysis), proprioception deficits (reduced awareness of limb position), and paralysis.
- In some cases, death (including euthanasia) has been reported as an outcome associated with reported adverse events.
- The updated label advises veterinarians to discuss these reported adverse events with pet owners and to weigh the benefits and risks for each individual dog.
Important context:
- These are reported adverse events collected through post-market pharmacovigilance. A reported association does not necessarily establish that Librela caused the event in every case, as some of these conditions can also occur in older dogs with OA from other causes.
- Over 18 million doses have been distributed globally, and the reported events, while serious, represent a small fraction of treated dogs.
- The FDA continues to monitor post-market safety data for Librela and all approved animal drugs.
- If your dog is currently receiving Librela and doing well, do not stop treatment without discussing it with your veterinarian. Abruptly stopping pain management can negatively affect your dog’s welfare.
What you should do: Talk to your veterinarian about the updated label information. Together, you can assess whether Librela’s benefits outweigh the risks for your individual dog, and discuss what signs to watch for.
Side Effects
The following side effects have been reported with Librela use. Always report any changes in your dog’s health or behavior to your veterinarian.
| Common Side Effects | Serious Side Effects (Contact Your Vet Promptly) |
|---|---|
| Injection site reactions (mild swelling, discomfort) | Unsteady gait or loss of coordination (ataxia) |
| Urinary tract infections | Seizures or tremors |
| Bacterial skin infections | Weakness in limbs or difficulty walking |
| Vomiting or diarrhea | Dragging of paws or stumbling |
| Sudden behavioral changes | |
| Signs of allergic reaction (facial swelling, hives, difficulty breathing) |
If you observe any neurologic signs, such as stumbling, weakness, loss of coordination, seizures, or changes in how your dog uses their legs, contact your veterinarian promptly. These signs may or may not be related to Librela, but your veterinarian needs to evaluate them.
Drug Interactions
Because Librela is a monoclonal antibody rather than a small-molecule drug, it has a different interaction profile than traditional medications:
- NSAIDs: Librela has been used concurrently with NSAIDs in some dogs during clinical trials. However, combining pain medications should only be done under direct veterinary supervision.
- Vaccines: No specific vaccine interactions have been identified in the product labeling, but inform your veterinarian about all treatments your dog receives.
- Other monoclonal antibodies (Cytopoint): Limited data on concurrent use. Discuss with your veterinarian.
Librela is not metabolized by the liver or kidneys, so traditional drug-drug interactions through these pathways are not expected. However, always disclose your dog’s full medication and supplement list to your veterinarian.
Contraindications
Librela should not be used in:
- Dogs with known hypersensitivity to bedinvetmab or any component of the formulation
- Librela has not been evaluated in dogs used for breeding, or in pregnant or lactating dogs
Your veterinarian will consider your dog’s complete health history, including any neurologic conditions, before recommending Librela. Dogs with a history of seizures or neurologic disease warrant particularly careful discussion about the benefits and risks.
Storage
Librela is stored and administered at your veterinary clinic:
- Store refrigerated at 36-46 degrees F (2-8 degrees C).
- Do not freeze.
- Protect from light.
Cost & Availability
Librela is a prescription-only medication administered at your veterinary clinic. There is no generic version available.
- Approximate cost per injection: $90-$250 depending on dog size and veterinary clinic
- Monthly cost: Same as injection cost (one injection per month)
- Additional office visit fees may apply depending on your veterinary clinic’s policies
Librela is not available for purchase at retail pharmacies. Each injection must be administered by a veterinarian or veterinary technician.
Librela vs. Other OA Pain Treatments
| Feature | Librela | Galliprant | Carprofen (Rimadyl) |
|---|---|---|---|
| Drug class | Monoclonal antibody (anti-NGF) | Piprant (EP4 antagonist) | Traditional NSAID (COX inhibitor) |
| Administration | Monthly injection at vet | Daily oral tablet | Daily oral tablet |
| Liver/kidney metabolism | No (protein recycling) | Yes (liver) | Yes (liver and kidney) |
| GI risk | Lower GI risk profile | May be lower GI risk vs. traditional NSAIDs | Moderate GI risk |
| Neurologic AE reports | Yes (label updated Feb 2025) | Not a primary concern | Not a primary concern |
| Monthly cost | $90-250 | $60-100 | $10-25 (generic) |
| Generic available | No | No | Yes |
The choice of OA pain medication depends on your dog’s individual health profile, response to treatment, cost considerations, and your veterinarian’s clinical judgment.
Frequently Asked Questions
How quickly does Librela start working? Many dogs show improvement within the first week after injection. Some owners report noticeable changes in mobility and comfort within a few days. However, response varies between dogs, and some may need two or more monthly injections before the full benefit is seen.
Can Librela be reversed if my dog has a reaction? No. Unlike some medications, there is no antidote or reversal agent for Librela. Because it is a protein that is gradually broken down by the body, its effects diminish over time (roughly over one month). If adverse effects occur, supportive veterinary care is provided while the drug clears the system.
Is Librela safe for older dogs? Librela was studied in dogs of various ages, including senior dogs, and many older dogs with OA benefit from treatment. However, older dogs may also have other health conditions that warrant discussion. The February 2025 label update applies to dogs of all ages. Your veterinarian will assess your individual dog’s situation.
What about Lenivia, the longer-acting version? Lenivia (izenivetmab) is Zoetis’ next-generation anti-NGF monoclonal antibody that lasts approximately 3 months per injection instead of 1 month. It received EU marketing authorization in December 2025 and Canadian approval in 2025, but is not yet FDA-approved for use in the United States. Your veterinarian can provide updates on its availability.
Should I stop Librela because of the label update? Do not stop or change any medication without consulting your veterinarian. If your dog has been receiving Librela and responding well without adverse effects, your veterinarian may recommend continuing treatment. The label update ensures that pet owners and veterinarians can make fully informed decisions together.
Sources & References
- FDA CVM - Librela (NADA 141-562) Approval Information
- FDA - Animal Drug Safety-Related Labeling Changes - Librela (February 18, 2025)
- FDA - Dear Veterinarian Letter: Librela
- Merck Veterinary Manual - Osteoarthritis in Dogs
- Zoetis - Librela Product Information
- VCA Hospitals - Managing Arthritis Pain in Dogs
This content is for informational purposes only and is not a substitute for professional veterinary advice. Always consult your veterinarian before starting, changing, or stopping any medication for your dog.