Now That He Has Arthritis

On the hall table there’s a folded information sheet from the clinic and a printed estimate for something called Librela. The vet confirmed arthritis this morning, offered two ways to treat his pain, a pill every day or an injection once a month, and said you could talk it through at the next visit.

He’s asleep in his bed a few feet away. The sheet is mostly a list of possible side effects, with nothing on how likely each one is.

If you only want the questions to bring to the next visit, they’re in What should I ask before he starts?

What is the medicine for?

The medicine is there to ease his pain enough that he keeps moving. None of the drugs below has been shown to repair the joint (Pye et al., 2022). They work on top of the two things that help nearly every arthritic dog: a healthy weight and regular, sensible exercise. For a dog carrying extra pounds, losing some of them can ease his walk.

The international guidelines for arthritis in dogs start from a base that includes weight and exercise and add medicine in layers as his signs and pain increase, judged by how he moves and feels rather than by his x-rays (Cachon et al., 2023). Those layers are laid out in Can a Dog Have Arthritis and Not Limp?

For moderate or severe pain, the specialists who wrote those guidelines all agreed on two kinds of first-line drug: an anti-inflammatory or an antibody injection. For a dog whose pain is still mild, they split. Three of the nine favored an anti-inflammatory first, and six considered either one a reasonable start (Cachon et al., 2023).

Why is an anti-inflammatory usually the first step?

Veterinary nonsteroidal anti-inflammatory drugs (NSAIDs), such as carprofen, meloxicam, firocoxib and deracoxib, have been the first-line pain relievers for arthritis in dogs for many years. Systematic reviews have found a high level of evidence that meloxicam, carprofen and firocoxib work, and no single NSAID has been shown to be consistently better or safer than the others (Pye et al., 2022).

These drugs need watching. Because they can affect the liver and kidneys, the FDA suggests a blood test before a dog starts an NSAID for long-term arthritis, and more at regular intervals (FDA). The international guidelines also recommend blood work for dogs with signs of arthritis (Cachon et al., 2023).

The FDA’s list of signs to watch for: vomiting, diarrhea, bloody or black stool, eating less, being less active, or yellowing of the gums or the whites of the eyes, even in a dog who was healthy before. If you see any of them, stop the medicine and call your vet (FDA).

Most liver reactions appear in the first three weeks, but watch for all of these signs the whole time he takes it, and for a little while after he stops (FDA).

The FDA rules out two pairings: two different NSAIDs at once, or an NSAID with a steroid such as prednisone, since both raise the risk to the digestive tract (FDA). And keep his pain relief to what his vet prescribes: ibuprofen and naproxen, sold for people, are toxic to dogs (what each one can do to a dog).

Every oral NSAID approved for dogs comes with a Client Information Sheet that your vet is meant to hand you with the first prescription and each refill. If you don’t get one, ask for it (FDA).

What about the monthly injection?

Librela (bedinvetmab) is a different kind of drug. It’s an antibody that blocks nerve growth factor, a signal involved in arthritis pain, and your vet gives it as an injection under the skin once a month. The FDA approved it in May 2023, on the strength of two field studies in which owners rated their dogs’ pain and how much it got in the way of daily life; dogs given Librela were compared with dogs given saline injections (FDA).

The label says the effect may not come until after the second dose. From six weeks on, both studies, one run in the US and one in Europe, had more dogs counted as a treatment success on Librela than on saline. At four weeks, the main test in both, only the European study showed a difference that held up statistically (Librela label).

Because the international guidelines list it next to NSAIDs as a first-line choice for moderate or severe pain, it gives his vet another option when he can’t take an NSAID (Cachon et al., 2023). In a 2025 study of 101 dogs, Librela and meloxicam controlled arthritis pain about equally well over eight weeks. Owners and vets knew which drug each dog was getting, and Zoetis, Librela’s maker, paid for the study (Innes et al., 2025).

Its safety record since approval is less settled. The FDA’s December 2024 letter to veterinarians described adverse events reported in dogs treated with Librela: ataxia (wobbliness), seizures, other nerve-related signs such as weakness, being unable to get up, and urinary incontinence, as well as increased thirst and urination. In some cases, the dog died or was euthanized (FDA, 2024).

The US label, revised in February 2025 and still the current one in November 2026, now lists those signs, along with lameness and muscle weakness, among the problems reported since approval (Librela label).

The label is careful about what those reports can show. Some problems never get reported, and it isn’t always possible to tell from the reports how often a problem happens or whether the drug caused it (Librela label). The FDA’s letter adds that a drug used in a very large number of animals can turn up problems that the studies before approval didn’t show (FDA, 2024).

A second question concerns the joints themselves. In human trials of similar antibodies, rapidly progressive osteoarthritis was reported in a small number of patients, more often when they also took an NSAID long term. The February 2025 label says this “has not been characterized or reported in dogs,” and that the safety of combining Librela with an NSAID hasn’t been established (Librela label).

In June 2026, thirteen veterinary surgeons and specialists wrote in the Journal of the American Veterinary Medical Association (JAVMA) that the drug “offers effective analgesia for many dogs,” and, in the same sentence, called rapidly progressive osteoarthritis “a critical safety concern” (von Pfeil et al., 2026).

Their commentary draws on case reports, adverse-event reports and the experience in people rather than a trial. In one series of 38 cases they cite, 79% of the dogs were also taking an NSAID. How often it happens, they write, is unknown and may be underestimated.

So the question goes to your vet, and the label sets the moment: it tells vets to give owners the Client Information Sheet and discuss possible side effects before each injection. If he also takes an NSAID, ask about the combination. If he hasn’t been able to exercise much, ask about an exercise plan: the label warns that a dog who becomes more active after treatment is at greater risk of injury (Librela label).

After an injection, if he is wobbly or loses his balance, is weak in his legs, can’t get up, has a seizure or loses bladder control, he needs to be seen today, at an emergency clinic if yours is closed. If he drinks or pees more, vomits, has diarrhea or seems unwell in any other way, call your vet right away (Librela label).

On any of these drugs, if his limp gets worse, he needs to be seen today, at an emergency clinic if yours is closed (what else to watch for in a limp). And if the injection stops helping after it had been working, tell your vet right away. It can mean the joint is getting worse, and the JAVMA authors write that a loss of effect in a dog who had been doing well “must prompt urgent reevaluation” (von Pfeil et al., 2026).

Is there a version that lasts three months?

Not in the US. Lenivia (izenivetmab) belongs to the same drug class as Librela, comes from the same company, and is given as an injection once every three months. The company launched it in Canada and the European Union in July 2026 (Zoetis), but as of November 2026 it does not appear in the FDA’s database of approved animal drugs (Animal Drugs @ FDA). The questions above would apply to it too if the FDA approves it.

What else might your vet suggest?

Some of these are added to a first-line drug, and some replace one.

• Galliprant (grapiprant). An anti-inflammatory that works differently from the standard ones. The FDA groups it with the NSAIDs, so it’s used instead of a standard NSAID, not on top of one (FDA). For arthritis, the one published trial as of a 2022 review found that after four weeks, 48% of the dogs on grapiprant counted as a treatment success, against 31% on a placebo (Pye et al., 2022). A 2026 review rated the evidence weak (Olding & Govendir, 2026). The only other study that compared it with dogs not given the drug gave a single dose to healthy lab dogs with a short-lived joint inflammation, caused by an injection to mimic arthritis, and it didn’t measurably change how they limped. The arthritis trial was paid for by the drug’s developer, the lab study by the maker of a rival NSAID (Olding & Govendir, 2026). How it compares with the standard NSAIDs over months of use is still unknown (Pye et al., 2022).
• Adequan (polysulfated glycosaminoglycan). A course of up to eight injections into the muscle over four weeks, given by your vet. It’s FDA-approved for the signs of non-infectious degenerative or traumatic arthritis, and an earlier systematic review, cited in the 2022 review, rated its evidence as moderate, from two trials (Pye et al., 2022). Its label says how it works in dogs’ joints isn’t known, and it isn’t used in dogs with bleeding disorders (Adequan Canine label).
• Glucosamine is a different product. Despite the related chemistry, the glucosamine sold in chews is not Adequan. In a 2022 analysis, glucosamine with chondroitin showed a marked lack of effect on arthritis pain, with one trial in nine showing any improvement (Barbeau-Grégoire et al., 2022).
• Amantadine. An add-on rather than a pain reliever on its own. In a trial of 31 dogs still lame despite an NSAID, all were put on meloxicam, and those given amantadine on top were more active three weeks later than those given a placebo, by their owners’ blinded assessment (Lascelles et al., 2008). It’s one small study.
• Gabapentin. A 2022 review found the evidence for it in dogs with arthritis lacking (Pye et al., 2022).
• Tramadol. In a trial where 35 dogs with arthritis each took tramadol, carprofen and a placebo for ten days at a time, tramadol did no better than the placebo, while carprofen helped (Budsberg et al., 2018). The test periods were short, and other small studies have had mixed results (Pye et al., 2022). If tramadol is part of his plan, ask your vet what it’s meant to add.
• Injections into the joint. Hyaluronic acid injections still need more evidence, and the stem-cell trials in a 2022 review were mostly small (Pye et al., 2022). In a 2022 trial of 14 dogs, stem cells did no better than hyaluronic acid (Kim et al., 2022).

Ratings are for the evidence that each option eases arthritis pain in dogs. They don’t rate safety: for that, see the NSAID and Librela sections above and the questions below. Strong: systematic reviews find a high level of evidence. Moderate: a review or at least one sizable controlled trial supports it, but studies are few or mixed. Limited: reviews find the evidence lacking, small or inconsistent, or trials found little or no benefit.

What should I ask before he starts?

You don’t need to pick the drug on your own: your vet has his exam, his bloodwork and his history in front of them. Your part is to leave the appointment knowing how the plan works. The FDA keeps its own list of questions for any pet medicine (FDA); for arthritis, these are the ones that matter most:

• What is this drug supposed to do for him, and how will we tell whether it’s working?
• Does he need blood tests before he starts, and how often afterward?
• Which side effects should I watch for, and which ones mean I stop and call you?
• Can it be combined with everything else he takes, including supplements and any other pain medicine?
• For the monthly injection: which signs after a dose mean he needs to be seen, and what should we do if it stops helping months in?
• When do we recheck, and do you call me or do I call you?
• If this one doesn’t suit him, what would we try next?
• Who do I call if something happens when the clinic is closed?

One rule covers the months after: don’t change the dose, skip it, stop it, or add another pain reliever without asking your vet first. The exception is the NSAID warning signs above, and any others your vet gives you: stop it and call.

What happens at the next visit?

The sheet and the estimate can stay on the hall table for now. The choice gets made at that visit, once you and your vet have talked it through. Take the questions above with you, along with the sheet, so the conversation starts from what you want to know.

Common questions

Is Librela safe for my dog?

Librela is FDA-approved and controls arthritis pain for many dogs, and questions about its safety are still open. Since approval, its label has added nerve, urinary and other problems reported in treated dogs, and it notes that some problems never get reported and that reports can’t always show how often a problem happens or whether the drug caused it. A question about whether it can speed up joint damage, especially alongside an NSAID, is also still open. Your vet is expected to go over possible side effects with you before each injection, and that’s the moment to ask what they would watch for in him. After an injection, a dog who is wobbly, weak in his legs, can’t get up, has a seizure, loses bladder control or is limping worse needs to be seen today, at an emergency clinic if yours is closed; call your vet right away if he drinks or pees more, vomits, has diarrhea or seems unwell in any other way, or if Librela stops helping after it had been working.

How long can a dog stay on an anti-inflammatory?

Dogs with advanced arthritis often need an anti-inflammatory for life, the international arthritis guidelines note. Earlier on, how long a dog needs one depends on how he responds to it, and for some dogs your vet may be able to taper it off. The FDA suggests baseline blood tests and regular rechecks for any dog on one long term. How often those rechecks happen is your vet’s call. Warning signs such as vomiting, black stool or eating less mean you stop it and call your vet.

Can a joint supplement replace his pain medicine?

A joint supplement isn’t a substitute for pain medication. In the international arthritis guidelines, omega-3 fatty acids, in a joint diet or as a supplement, are the one nutritional addition all nine authors recommended for dogs with signs of arthritis, while glucosamine and similar products had the support of only a minority. Ask your vet before adding one, and don’t drop a prescribed pain reliever for it.

Sources

• Barbeau-Grégoire M, et al. A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and Feline Osteoarthritis. International Journal of Molecular Sciences. 2022;23(18):10384. Link
• Budsberg SC, et al. Lack of effectiveness of tramadol hydrochloride for the treatment of pain and joint dysfunction in dogs with chronic osteoarthritis. JAVMA. 2018;252(4):427-432. Link
• Cachon T, et al. COAST Development Group’s international consensus guidelines for the treatment of canine osteoarthritis. Frontiers in Veterinary Science. 2023;10:1137888. Link
• Innes JF, et al. A randomised, parallel-group clinical trial comparing bedinvetmab to meloxicam for the management of canine osteoarthritis. Frontiers in Veterinary Science. 2025;12:1502218. Link
• Kim S, et al. Intra-articular injections of allogeneic mesenchymal stromal cells vs. high molecular weight hyaluronic acid in dogs with osteoarthritis: exploratory data from a double-blind, randomized, prospective clinical trial. Frontiers in Veterinary Science. 2022;9:890704. Link
• Lascelles BDX, et al. Amantadine in a multimodal analgesic regimen for alleviation of refractory osteoarthritis pain in dogs. Journal of Veterinary Internal Medicine. 2008;22(1):53-59. Link
• Olding G, Govendir M. Does grapiprant reduce osteoarthritic pain in dogs? Veterinary Evidence. 2026;11(2). Link
• Pye C, et al. Advances in the pharmaceutical treatment options for canine osteoarthritis. Journal of Small Animal Practice. 2022;63(10):721-738. Link
• von Pfeil DJF, et al. Bedinvetmab (Librela/Beransa) in dogs raises safety concerns, including rapidly progressive osteoarthritis, and warrants vigilant adverse event reporting. JAVMA. Online ahead of print, June 2026. Link
• U.S. Food and Drug Administration. FDA Approves First Monoclonal Antibody for Dogs with Osteoarthritis Pain. May 5, 2023. Link
• U.S. Food and Drug Administration. Dear Veterinarian Letter Notifying Veterinarians about Adverse Events Reported in Dogs Treated with Librela. December 16, 2024. Link
• U.S. Food and Drug Administration. Get the Facts about Pain Relievers for Pets. Content current as of 09/29/2022. Link
• U.S. Food and Drug Administration. Medications for Your Pet: Questions for Your Vet. Content current as of 02/20/2024. Link
• U.S. Food and Drug Administration. Animal Drugs @ FDA (searched November 4, 2026). Link
• Librela (bedinvetmab injection) label, revised February 2025. DailyMed. Link
• Adequan Canine (polysulfated glycosaminoglycan) label. DailyMed. Link
• Zoetis. Zoetis Launches Lenivia (izenivetmab injection) in Canada and the European Union. July 15, 2026. Link