Librela Adverse Events: Every Sign in the FDA's 10,068 Dog Reports (2023-2024)
By Sarah Bennett · Last updated October 8, 2026 · 11 min read
This page is the FDA's own Librela adverse events listing, turned into something you can read: the Librela FDA adverse event reports, sign by sign. The tables below come from the Center for Veterinary Medicine's response dated January 23, 2025. That letter states "Number of reports in dogs: 10,068" for bedinvetmab, the antibody in Librela, and its search runs from May 5, 2023 through December 31, 2024. Those reports name 1,408 distinct clinical signs, 37,769 sign mentions in all. The April 1, 2024 release covered the same start date through March 31, 2024 and listed 3,342 dog reports. The later total includes those earlier months. We parsed the full later document, ranked every sign, grouped them into eleven categories plus a long tail, and put both tables up for download. The report and sign counts are counts from the FDA file. Percentages and grouped totals are arithmetic from those counts.
How to read this page in one minute
- The listing counts signs, not dogs. One report often carries several signs, so the category totals add up to more than 10,068.
- Percentages are the share of the 10,068 dog reports that mention a sign.
- The categories are ours, assigned by keyword; the FDA lists signs alphabetically without grouping.
- A report is a report. It is not a finding that Librela caused the sign, and the FDA says so in the same document.
- The file has no denominator. How many dogs received Librela in the window is not in it; the manufacturer's global figure is further down.
Download the full table: librela-fda-ade-signs-2023-2024.csv (1,408 rows: sign, count, percent of the 10,068 reports, category). The earlier window is librela-fda-ade-signs-through-2024-03-31.csv (927 rows, 3,342 dog reports). The FDA's original spellings are preserved in both files.
What This Dataset Is, and Is Not
The tables and the chart use the January 23, 2025 listing. Its cover letter searches reports received from May 5, 2023 through December 31, 2024. The listing header inside the same PDF dates the cumulative range through January 1, 2025. The 10,068 figure belongs to the cover letter's search. The April 1, 2024 listing is the shorter window, May 5, 2023 through March 31, 2024. Reports come from veterinarians and owners, directly or through the manufacturer.
Three things the FDA itself says about this kind of data, and that shape everything below:
It cannot establish cause. The listing states plainly: "For any given ADE report, there is no certainty that the reported drug caused the adverse event." A twelve-year-old dog with arthritis is a dog with other things going on, and a report captures what happened after an injection, not what happened because of it.
It cannot be used to compare drugs. The report count depends on how many animals got the drug, how long it has been on the market, and how much attention it is getting. A drug in the news collects more reports.
It has no denominator. The file counts reports; it does not say how many dogs were treated. So a percentage on this page is "share of reports," never "share of dogs on Librela."
Our full discussion of what the signs mean for an individual dog, including the FDA's December 2024 Dear Veterinarian Letter and the manufacturer's response, is in the Librela side effects guide. This page is the data behind it.
The 40 Most Reported Librela Adverse Events
Percent is the share of the 10,068 dog reports that include the sign. Spellings are Americanized for reading; the CSV keeps the FDA's terms.
| # | Sign | Reports | Share of dog reports | Category |
|---|---|---|---|---|
| 1 | Lethargy | 1,143 | 11.4% | General and systemic |
| 2 | Death by euthanasia | 968 | 9.6% | Death |
| 3 | Polydipsia (drinking more) | 904 | 9.0% | Urinary |
| 4 | Polyuria (urinating more) | 862 | 8.6% | Urinary |
| 5 | Vomiting | 800 | 7.9% | Gastrointestinal |
| 6 | Diarrhea | 796 | 7.9% | Gastrointestinal |
| 7 | Ataxia (wobbliness) | 712 | 7.1% | Neurological |
| 8 | Urinary incontinence | 680 | 6.8% | Urinary |
| 9 | Seizure, not otherwise specified | 638 | 6.3% | Neurological |
| 10 | Lack of efficacy, not otherwise specified | 602 | 6.0% | Lack of efficacy |
| 11 | Partial lack of efficacy | 583 | 5.8% | Lack of efficacy |
| 12 | Limb weakness | 547 | 5.4% | Musculoskeletal and mobility |
| 13 | Death | 539 | 5.4% | Death |
| 14 | Urinary tract infection | 537 | 5.3% | Urinary |
| 15 | Anorexia | 463 | 4.6% | Gastrointestinal |
| 16 | Not eating | 452 | 4.5% | Gastrointestinal |
| 17 | Panting | 441 | 4.4% | Respiratory and cardiac |
| 18 | Decreased appetite | 411 | 4.1% | Gastrointestinal |
| 19 | Inappropriate urination | 405 | 4.0% | Urinary |
| 20 | Unable to walk | 367 | 3.6% | Musculoskeletal and mobility |
| 21 | Hind limb paresis (partial paralysis) | 319 | 3.2% | Neurological |
| 22 | Proprioception deficit | 299 | 3.0% | Neurological |
| 23 | Weight loss | 299 | 3.0% | General and systemic |
| 24 | Emesis, multiple | 281 | 2.8% | Gastrointestinal |
| 25 | Unable to stand | 258 | 2.6% | Musculoskeletal and mobility |
| 26 | Elevated alanine aminotransferase (ALT) | 250 | 2.5% | Laboratory values |
| 27 | Elevated blood urea nitrogen (BUN) | 242 | 2.4% | Laboratory values |
| 28 | Lameness | 219 | 2.2% | Musculoskeletal and mobility |
| 29 | Not himself/herself | 217 | 2.2% | Behavioral |
| 30 | Weakness | 217 | 2.2% | Musculoskeletal and mobility |
| 31 | Pain, not otherwise specified | 214 | 2.1% | Musculoskeletal and mobility |
| 32 | Walking difficulty | 210 | 2.1% | Musculoskeletal and mobility |
| 33 | Fecal incontinence | 204 | 2.0% | Gastrointestinal |
| 34 | Decreased urine concentration | 203 | 2.0% | Laboratory values |
| 35 | Behavioral disorder, not otherwise specified | 199 | 2.0% | Behavioral |
| 36 | Falling | 188 | 1.9% | Musculoskeletal and mobility |
| 37 | Musculoskeletal disorder, not otherwise specified | 188 | 1.9% | Other |
| 38 | Hind limb ataxia | 186 | 1.8% | Neurological |
| 39 | Leukocytosis, not otherwise specified | 185 | 1.8% | Laboratory values |
| 40 | Proteinuria | 180 | 1.8% | Laboratory values |
The remaining 1,368 signs each appear in 179 or fewer reports. Of those, 940 appear ten times or fewer, and 305 appear exactly once. The full list is in the download.
In the April 2024 file, death by euthanasia was eighth, with 241 mentions. In this file it is second, with 968.
The Signs Grouped Into Categories
Sign mentions, not dogs. A report with vomiting and diarrhea contributes two mentions to Gastrointestinal.
| Category | Sign mentions | Share of all mentions | Distinct signs |
|---|---|---|---|
| Urinary | 4,869 | 12.9% | 54 |
| Neurological | 4,810 | 12.7% | 106 |
| Gastrointestinal | 4,656 | 12.3% | 74 |
| Other | 4,429 | 11.7% | 638 |
| Laboratory values | 4,306 | 11.4% | 87 |
| Musculoskeletal and mobility | 4,122 | 10.9% | 85 |
| General and systemic | 2,831 | 7.5% | 68 |
| Skin and injection site | 1,899 | 5.0% | 166 |
| Behavioral | 1,722 | 4.6% | 39 |
| Death | 1,532 | 4.1% | 6 |
| Respiratory and cardiac | 1,394 | 3.7% | 73 |
| Lack of efficacy | 1,199 | 3.2% | 12 |
"Other" is the long tail: 638 signs that did not fit a category cleanly. The category rules are in the parsing script linked at the bottom, so anyone can rerun them differently.
Four Things the Librela Adverse Events Data Shows
1. Lethargy still leads, and death by euthanasia is now second. The five everyday signs from the earlier table, lethargy, drinking more, urinating more, vomiting, and diarrhea, now total 4,505 mentions, 11.9 percent of all sign mentions. Death by euthanasia sits between lethargy and the drinking row.
2. The urinary signs still cluster. Polydipsia, polyuria, urinary incontinence, urinary tract infection, and inappropriate urination together appear 3,388 times. Those signs often travel together in one report, so 3,388 is a count of mentions. The urinary category as a whole is 4,869 mentions across 54 signs. Neurological is close behind, at 4,810 mentions across 106 signs. Our side effects guide covers what to watch for after a first injection.
3. The Librela neurological side effects are a real and sizable cluster. Ataxia appears in 7.1 percent of the dog reports and seizure, not otherwise specified, in 6.3 percent. The neurological category holds 4,810 mentions across 106 signs. Eight signs this page has tracked across both files, ataxia, seizure, limb weakness, hind limb paresis, proprioception deficit, unable to walk, unable to stand, and hind limb ataxia, sum to 3,326 mentions. Limb weakness, unable to walk, and unable to stand sit in the mobility category in the table above. This is the group the FDA named in its Dear Veterinarian Letter, and the group with the least overlap with ordinary arthritis. A dog who was stiff and is now wobbly has changed category. The home check in our weak back legs guide is how to tell the two apart.
4. Death appears under two large signs. "Death by euthanasia" 968 times and "Death" 539 times. Because a report can carry more than one sign, 1,507 is an upper bound on the number of reports involving one of those two signs. Four smaller signs, sudden death (12), found dead (5), unrelated death (5), and unexplained death (3), bring the death category to 1,532 mentions. None of this says the drug was the reason. Many of these dogs are old and have other diseases. The file records the sign, not which of those was the cause. What the number does say is that one of those two signs was recorded in up to 1,507 of the 10,068 reports, 15.0 percent when rounded to one decimal. That is a number worth knowing before an injection, and worth putting next to the denominator below.
The Denominator the FDA Does Not Have
The manufacturer does. Zoetis published its global pharmacovigilance data in Frontiers in Veterinary Science in April 2025, covering February 2021 through June 2024. In that period 18,102,535 doses were sold worldwide, with 17,162 adverse events reported in dogs, which the authors put at 9.48 events per 10,000 doses.
Two cautions on putting the two datasets side by side. The Zoetis figure is global and spans three and a half years; the FDA file on this page is United States reports from May 5, 2023 through December 31, 2024, so they are not the same population. And the Zoetis paper was written by the company that sells the drug, which does not make it wrong, but does make it worth reading alongside the independent analysis of musculoskeletal events by Farrell and colleagues in the same journal, which is discussed in our side effects guide.
The January 23, 2025 file states the limit directly: "Accumulated ADE reports should not be used to calculate incidence rates or estimates of drug risk, because there is no accurate way to determine how many animals were actually given the drug, which is needed as the denominator in calculations of incidence and relative risk."
Read together, the honest summary is: a low absolute rate of reported events per dose, and within the reports that do arrive, a recognizable pattern of urinary, gastrointestinal and neurological signs in a population of old dogs.
How to Use This Before or After an Injection
- Before: ask the vet which of the top categories your dog is already at risk for. A dog with kidney values on the edge, or a history of seizures, is a different conversation from a dog with none of that. Our Librela guide covers what the drug does and who it suits.
- After: the signs to watch in the first weeks are the ones in the table, and the ones that change the picture are the neurological ones: wobbliness, knuckling, a back end that buckles, a seizure. Those are same-day calls.
- If something happens: report it. To the vet, who reports to Zoetis and the FDA, or directly to the FDA. The 10,068 reports on this page exist because people did.
- If you are weighing alternatives: the Librela alternatives guide sets the other options next to it, and Adequan is the other injectable.
Frequently Asked Questions
How many adverse event reports has the FDA received for Librela?
The January 23, 2025 response lists 10,068 reports in dogs for May 5, 2023 through December 31, 2024. The same letter also lists 3 reports in cats, 1 in another species, and 69 human accidental exposures, for a total of 10,141. The April 1, 2024 file, covering the same start date through March 31, 2024, lists 3,342 reports in dogs. The later total includes the earlier months.
How many dogs have died from Librela?
The file cannot answer that, and neither can this page. In the January 23, 2025 listing it records 968 mentions of "death by euthanasia" and 539 of "death," so up to 1,507 of the 10,068 reports involve one of those two signs. It does not record whether Librela caused any of them, and the FDA states that no report on its own establishes cause. Librela is given to old dogs, and old dogs die of many things.
What are the most common Librela adverse events?
By report count in the January 23, 2025 file: lethargy (1,143), death by euthanasia (968), increased drinking (904), increased urination (862), and vomiting (800). Lethargy is in 11.4 percent of the dog reports. Death by euthanasia is in 9.6 percent.
Are the neurological side effects of Librela common?
Common in the reports, unknown in the treated population. Ataxia alone appears in 7.1% of the 10,068 dog reports and seizure, not otherwise specified, in 6.3%. The neurological category holds 4,810 mentions across 106 signs. Without knowing how many dogs were treated in the same window, the file cannot turn that into a rate per dog. The manufacturer's global figure for all adverse events is 9.48 per 10,000 doses.
Where does this data come from, and can I check it?
From two FDA Center for Veterinary Medicine listings for bedinvetmab, both linked in the sources. Those two files are the Librela FOIA data behind the tables. The counts in the tables are from the January 23, 2025 file. The April 1, 2024 file is the shorter window, kept as its own download. Our parsing script and category rules are downloadable below, and the CSV reproduces every count in the later file.
Sources
- U.S. Food and Drug Administration, Center for Veterinary Medicine. CVM ADE Comprehensive Clinical Detail Report Listing, bedinvetmab. FOIA response dated January 23, 2025. Cover letter search: reports received May 5, 2023 through December 31, 2024. Source of the 10,068 dog-report count and of the table on this page. Read October 8, 2026. fda.gov/media/185291
- U.S. Food and Drug Administration, Center for Veterinary Medicine. CVM ADE Comprehensive Clinical Detail Report Listing, bedinvetmab. FOIA response dated April 1, 2024, covering reports received May 5, 2023 through March 31, 2024. Source of the 3,342 count. fda.gov/media/178955
- U.S. Food and Drug Administration, Center for Veterinary Medicine. ADE listing cover notes. Source of the causation caveat quoted above. fda.gov/media/186109
- Zoetis pharmacovigilance data, Frontiers in Veterinary Science, April 2025. Source of the doses-sold and events-per-10,000 figures. frontiersin.org
- Parsing script and category rules: build-librela-ade-data.mjs. Rerun it against a newer FOIA release to update this page.
Keep Reading
- Librela side effects in dogs, what each sign means for an individual dog
- Librela for dogs: does it work, the drug, the cost, and who it suits
- Librela alternatives, if the table above changed your mind
- Old dog back legs weak or giving out, the home check that separates pain from nerve signs
If you find an error in the table, write to us. The counts are only as good as the parsing, and the file is public for anyone to check.
About the authors
Sarah Bennett researches senior dog care from a home centered on her Border Collie, Lucy. I am not a veterinarian; every count on this page comes from the FDA document linked at the claim, and the interpretation is labeled as ours.
Leo Bennett handles the reading and fact-checking behind these pieces, including rerunning the parser against the source PDF and checking the category totals against the sign counts.
Sarah and Leo Bennett are pen names. Senior Dog Daily is written and checked by a small editorial team; see About.