Adequan Canine (polysulfated glycosaminoglycan, or PSGAG) and Librela (bedinvetmab injection) are both veterinary-administered injectable treatments for canine osteoarthritis, but they approach the disease from fundamentally different angles. Adequan targets the joint tissue itself — it is the only FDA-approved disease-modifying osteoarthritis drug (DMOAD) for dogs. Librela targets pain signaling — it is a monoclonal antibody that blocks nerve growth factor (NGF) to reduce the sensation of pain.

This comparison covers mechanism, dosing schedule, evidence, safety, cost, and practical decision-making. It is written for the dog owner trying to understand what their veterinarian is recommending — and for the veterinary team explaining the difference.

Quick answer

Adequan Canine is an intramuscular injection given twice weekly for up to 4 weeks (maximum 8 injections per course). It is derived from glycosaminoglycans extracted from bovine tracheal cartilage. Its FDA label indication is for the control of signs associated with non-infectious degenerative and/or traumatic arthritis of canine synovial joints. It reaches synovial joints within 2 hours of injection, is detected in cartilage and subchondral bone by 96 hours, and is classified as a disease-modifying drug because it inhibits catabolic enzymes and promotes anabolic activity in the joint — meaning it aims to slow cartilage degradation, not just mask pain.

Librela is a subcutaneous injection given once a month. It is a caninized monoclonal antibody that binds and neutralizes nerve growth factor (NGF), a protein elevated in arthritic joints that drives pain signaling to the brain. It provides pain relief but does not modify the underlying joint disease process. It is metabolized through normal protein degradation pathways with minimal liver or kidney involvement.

They are not interchangeable. They can be used together, because they work through completely different mechanisms.

Mechanism: what each drug targets

The distinction matters: Adequan treats the disease process in the joint. Librela treats the pain that results from the disease. They answer different clinical questions.

Dosing and schedule

Adequan Canine

• Dose: 2 mg per pound of body weight (0.02 mL/lb, or 1 mL per 50 lb) by intramuscular injection only.
• Schedule: Twice weekly for up to 4 weeks. Maximum of 8 injections per treatment course.
• Timing: PSGAG reaches synovial joints within 2 hours of IM injection. Detectable levels in synovial fluid and articular cartilage last up to 72 hours. Adequan is detected in cartilage and subchondral bone at 96 hours.
• Retreatment: The label states that the dosing regimen can be repeated as needed over the dog's lifetime upon reoccurrence of clinical signs. In practice, many veterinarians recommend a repeat course every 4–6 months, though the exact interval depends on the individual dog.
• Onset: Pet parents may see signs of improvement in mobility within one month.

Librela

• Dose: Minimum 0.23 mg/lb (0.5 mg/kg) by subcutaneous injection, dosed by weight range.
• Schedule: Once monthly, ongoing for the dog's life.
• Onset: Some improvement within the first week. Steady-state levels are reached after approximately 2 monthly doses (about 8 weeks), so full effect may take 2–3 months to evaluate.
• Administration: Given in the clinic. Each vial is single-use with no preservative.

The practical difference is significant: Adequan requires a loading series of 8 injections over 4 weeks, then periodic repeat courses. Librela requires a single injection once a month, every month, indefinitely. For owners who cannot bring their dog to the clinic twice a week for a month, Librela's monthly schedule is simpler. For owners who prefer a treatment course that can be paused and restarted, Adequan offers that flexibility.

Evidence: what the studies show

Adequan Canine

Approval was based on a distribution study showing PSGAG reaches synovial fluid and articular cartilage after IM injection, and a blinded, placebo-controlled field trial. In the field trial, dogs treated with PSGAG at the labeled dose showed statistically significant improvement in lameness scores compared to placebo. A peer-reviewed study also supported efficacy.

The package insert notes: "The specific mechanism of action of Adequan in canine joints is not known." Despite this, the FDA classified it as a DMOAD because clinical studies demonstrated changes in cartilage and joint tissues beyond just symptom control.

Librela

Two masked, randomized, controlled field studies (U.S. and European, totaling 553 dogs over 84 days) showed that Librela-treated dogs had greater improvement in owner-assessed pain scores compared to saline controls. A 2025 comparator study (Innes et al., Frontiers in Veterinary Science) found Librela equivalent in pain relief to the NSAID meloxicam over 56 days, with fewer adverse events.

Librela has not been studied head-to-head against Adequan Canine. No direct comparison trial exists.

Safety considerations

Adequan Canine

• Contraindicated in dogs with hypersensitivity to PSGAG or known/suspected bleeding disorders. PSGAG has anticoagulant properties at high doses.
• Caution in dogs with renal or hepatic disease — PSGAG is excreted primarily via the kidneys.
• The label safety study used doses up to 10× the recommended dose for over 3× the recommended duration. One dog in the highest dose group developed clinical signs, but no drug-related mortality was observed.
• Post-injection soreness at the injection site is the most commonly reported adverse event in practice.
• Long-standing safety profile with post-approval monitoring reported to the FDA since 1997.

Librela

• Contraindicated in dogs with known hypersensitivity to bedinvetmab, and in breeding, pregnant, or lactating dogs. Not for dogs under 12 months.
• The 2025 U.S. label update added post-approval adverse events including neurologic signs (ataxia, seizures, paresis), urinary incontinence, and death. These events are rare relative to the millions of doses distributed globally.
• Safe concurrent long-term NSAID use has not been established. A human signal for rapidly progressive osteoarthritis (RPOA) with anti-NGF antibodies combined with NSAIDs has not been reproduced in dogs.
• Because Librela is metabolized as a protein, it has minimal liver or kidney involvement. This makes it an option for dogs with compromised renal or hepatic function where traditional NSAIDs are risky.

Can they be used together?

Yes. Because Adequan works on joint tissue and Librela works on pain signaling through an entirely separate mechanism (antibody vs glycosaminoglycan, joint-targeted vs NGF-targeted), there is no pharmacologic reason they cannot be combined. Many multimodal OA plans use both — Adequan for the disease-modifying effect on cartilage and Librela for sustained pain control. The decision should be made by the treating veterinarian based on the individual dog's needs and the owner's treatment goals.

Cost considerations

Neither drug is inexpensive, and costs vary by clinic, region, and the dog's size.

Cost should be discussed with the prescribing veterinarian. Pet insurance policies that cover osteoarthritis treatment may reimburse for both drugs, but coverage depends on the individual policy, whether the condition is pre-existing, and whether the policy covers injectable medications administered in-clinic.

When to choose Adequan

• Early-stage OA where slowing cartilage degradation is a priority.
• Dogs where the owner and veterinarian want a disease-modifying approach, not just pain control.
• Dogs that cannot take NSAIDs and where pain is not severe enough to warrant Librela alone.
• Dogs where periodic treatment courses are preferred over indefinite monthly injections.
• As an adjunct to Librela or NSAIDs for a multimodal approach.

When to choose Librela

• Dogs with moderate to severe OA pain where sustained pain control is the primary goal.
• Dogs with compromised kidney or liver function where NSAID use is risky.
• Dogs that have not responded adequately to NSAIDs or Adequan alone.
• Owners who prefer a monthly injection over twice-weekly injections for a month.
• Dogs that need pain relief while the veterinarian evaluates or manages comorbidities.

When neither is enough alone

Moderate to severe canine OA often requires more than one medication. Current international consensus guidelines from the COAST development group recommend a multimodal approach that may include:

• Weight management and exercise modification
• An NSAID or Galliprant for inflammation and pain
• Librela for sustained NGF-mediated pain control
• Adequan Canine for disease modification
• Gabapentin or amantadine for neuropathic pain components
• Physical rehabilitation (laser, hydrotherapy, therapeutic exercise)
• Joint supplements with evidence of benefit (omega-3 fatty acids)
• Environmental modification (ramps, non-slip surfaces, orthopedic bedding)

The specific combination should be tailored to the individual dog by the treating veterinarian.

What to discuss with your veterinarian

• What stage is my dog's OA? Radiographs and a thorough orthopedic exam help determine whether disease modification (Adequan) or pain control (Librela) should be prioritized — or whether both are appropriate.
• Can my dog take both? If your dog has moderate to severe OA, ask whether combining Adequan and Librela makes sense as part of a multimodal plan.
• What are the monitoring requirements? Adequan courses are time-limited, but baseline bloodwork is recommended. Librela is ongoing and should be reassessed at each monthly visit.
• What if one does not work? Ask about the expected timeline for improvement with each drug and what the next step is if the response is inadequate.
• Is my dog a candidate for NSAIDs as well? Some dogs benefit from a combination of an oral NSAID (like Galliprant or carprofen), Adequan, and Librela — but NSAID and Librela concurrent use requires veterinary guidance due to the unresolved long-term safety question.
• How does cost factor into the plan? Both drugs require ongoing financial commitment. Discuss which combination provides the best value for your dog's specific needs.

Key points

• Adequan Canine is a disease-modifying injectable that targets joint tissue — cartilage, synovial fluid, and subchondral bone. Librela is a pain-control injectable that blocks nerve growth factor.
• Adequan requires a loading course of 8 injections over 4 weeks, with periodic repeat courses. Librela is a once-monthly injection given indefinitely.
• They can be combined because they work through completely different mechanisms.
• No head-to-head trial exists. The choice depends on the dog's OA stage, comorbidities, owner preferences, and the veterinarian's assessment of treatment priorities.
• Both are prescription veterinary-administered drugs. Discuss monitoring, cost, and the multimodal plan with your veterinarian.

Sources

• FDA — FOI Summary for Adequan Canine (NADA 141-038). https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/3696
• Adequan Canine — Full Prescribing Information. https://adequancanine.com/Content/pdf/Adequan_Canine_Pkg_Insert_0732.pdf
• Adequan Canine — Dosing and Administration. https://adequancanine.com/veterinarians/dosing-and-administration
• FDA — Animal Drug Safety-Related Labeling Changes: Librela. https://www.fda.gov/animal-veterinary/drug-labels/animal-drug-safety-related-labeling-changes
• Zoetis — Librela Prescribing Information (NADA 141-562). https://www.zoetisus.com/content/_assets/docs/vmips/package-inserts/librela-prescribing-information.pdf
• Zoetis — Results from First Study Comparing Librela to Meloxicam (March 2025). https://news.zoetis.com/press-releases/press-release-details/2025/Zoetis-Announces-Results-from-First-Study-Comparing-Librela-bedinvetmab-injection-to-the-NSAID-Meloxicam-2025-xPPs4219G3/default.aspx
• Cachon T et al. (2023) — COAST Development Group's International Consensus Guidelines for the Treatment of Canine Osteoarthritis. Frontiers in Animal Science. https://doi.org/10.3389/fvets.2023.1137888
• Innes JF et al. (2025) — A Randomised, Parallel-Group Clinical Trial Comparing Bedinvetmab to Meloxicam for the Management of Canine Osteoarthritis. Frontiers in Veterinary Science. https://doi.org/10.3389/fvets.2025.1502218