Research Library Cats & Solensia
Solensia:
What every cat family should know
A dedicated Solensia resource for the people who love cats.
Explore the research, understand safety updates, and bring better questions to your veterinarian. Your cat’s wellbeing is part of our mission.
For every cat. For every family.Featured FDA safety update October 5, 2026 NADA 141-546
Solensia label update: serious reactions may result in death or euthanasia
The FDA’s October 5, 2026 entry documents new safety-related labeling, including post-approval adverse events and a Client Information Sheet for cat owners.
“Serious side effects can occur, with or without warning, and in some situations may result in death.”
Client Information Sheet reproduced in the FDA update
Reported outcomes: Death, including euthanasia, was reported following some listed adverse events. These include neurologic problems, severe skin reactions, and anaphylaxis.
Before every injection: The revised labeling directs veterinarians to provide and review the Client Information Sheet and discuss possible reactions with the owner.
How to interpret this: FDA cautions that post-approval reports cannot reliably establish how frequently events occur or whether product exposure caused them.
Read the FDA label changes and Client Information SheetIf your cat develops concerning changes, contact your veterinarian promptly.
A little context
What is Solensia?
Solensia is the brand name for frunevetmab, a cat-specific monoclonal antibody administered by a veterinarian as a monthly injection for osteoarthritis pain. It targets nerve growth factor (NGF), a protein involved in pain signaling. FDA approval announcement ↗
Its approved role is pain control. More comfortable movement does not establish that damaged joints have healed. Current owner information ↓
Read with perspective
What the evidence can tell us
Benefit, suspected harm, and biological explanations need different kinds of evidence. Keep those distinctions in view.
Short-term pain benefit
A randomized feline trial found improvement in some pain-related measures. It also recorded more skin disorders in treated cats.
Clinical trialReported adverse outcomes
Case series and reporting analyses identify concerns worth examining. A statistical reporting signal is not the percentage of cats harmed.
Feline reporting analysisJoint risk and mechanisms
The joint-safety literature raises questions. The frequency, causes, and proposed mechanisms of these outcomes in cats remain unresolved. Dog or human findings cannot settle feline risk.
Joint-safety commentaryGo to the original source
The Solensia source library
Research, regulator materials, public records, journalism, and the petition—each with its scope and limits.
FDA label change: serious reactions may result in death or euthanasia
The October 5 labeling revision adds reported adverse events, including outcomes of death or euthanasia. The new Client Information Sheet warns that serious reactions may be fatal, and the revised label directs veterinarians to review it with owners before every injection.
Evidence & limits
Official safety update
Cats · U.S. labeling
The FDA cautions that spontaneous reports cannot reliably establish frequency or a causal link to exposure.
Open access
Pain relief in a controlled feline trial
Three monthly injections improved some owner-assessed pain and function measures versus placebo. Skin disorders were recorded in 32 of 182 treated cats and 8 of 93 placebo cats.
Evidence & limits
Controlled clinical evidence
275 cats · Randomized, blinded trial
This supports short-term benefit and identifies observed skin events. The trial's size and duration cannot settle uncommon or long-term risks. Results varied by measure and assessment time.
Funding & disclosures: Funded by Zoetis; several authors disclosed company employment or other financial relationships.
Reference: DOI: 10.1111/jvim.16291
Open-access full text
Safety signals in feline adverse-event reports
An analysis of 5,248 frunevetmab reports found 19 statistical reporting signals, including skin conditions, arthritis and paresis (weakness or partial loss of movement).
Evidence & limits
Reporting signals
U.S. cat reports · 2022–2024
A disproportionality signal means an event is reported relatively more often in the database. It is hypothesis-generating, not an estimate of incidence or proof of causation. The analysis predates the October 2026 U.S. label update.
Reference: DOI: 10.1093/jvimsj/aalag003
Open-access full text
Itching and skin lesions in five cats
Five cats developed substantial itching and self-inflicted head or neck lesions 3–18 days after an injection. The three cats given further injections after the initial reaction had another reaction.
Evidence & limits
Limited clinical observations
Five cats · Clinical case series
Timing and recurrence provide useful clinical detail, but a small, uncontrolled case series cannot determine population risk or exclude every alternative explanation.
Reference: DOI: 10.1177/1098612X231198416
Open-access full text
Emerging concerns about joint changes
Discusses unusually rapid arthritic changes in dogs and cats receiving anti-NGF antibodies. The Citizen Petition cites its feline example in the discussion of structural joint safety.
Evidence & limits
Limited clinical observations
Dogs and cats · Clinical editorial
An editorial describing selected observations does not establish how often joint damage occurs or prove that Solensia caused it. Findings in dogs cannot be assumed to apply equally to cats.
Reference: Veterinary and Comparative Orthopaedics and Traumatology 39:157–161. DOI: 10.1055/a-2846-8347. See also petition pages 39–40.
PubMed record with publisher link
UK update: coordination, thirst and urination
Adds ataxia (loss of coordination), increased urination and increased thirst to product information, classified as very rare: fewer than 1 in 10,000 treated animals, including isolated reports.
Evidence & limits
Official safety update
Cats · UK product information
This is a UK labeling classification. It should not be treated as a risk estimate calculated from FDA reports or applied to all reported outcomes.
Open access
European authorization and assessment materials
The Solensia medicine page links to the public assessment report, product information and authorization history, and directs readers to the Veterinary Medicines Information website for up-to-date product details.
Evidence & limits
Official regulatory record
Cats · European Union
EU documents have their own revision dates and approved wording. Check the current product information for your jurisdiction.
Open-access regulatory resource
FDA Solensia adverse-event report release
The release lists 7,626 reports involving cats, received from January 13, 2022 through June 30, 2026. One report may contain several clinical signs.
Evidence & limits
Public reporting records
Cats · U.S. reporting database
These are submitted reports, not confirmed drug-caused injuries. Without a reliable count of exposed cats, they cannot establish incidence or individual risk. Clinical-sign totals should not be added together.
Open-access PDF · 47 pages
UK disclosure on rapidly progressive arthritis reports
A response to a records request about suspected rapidly progressive arthritis following Solensia explains the regulator's searches and coding limitations.
Evidence & limits
Public reporting records
Solensia · UK disclosure
Reports and narrative searches are not independently confirmed cases. This disclosure does not establish the rate or cause of joint damage in treated cats.
Open access
Cat families question Solensia risk disclosure
A cat-focused investigation features owners who associated their cats' deterioration or deaths with Solensia, alongside responses from FDA and Zoetis. Zoetis expressed confidence in labeled use.
Evidence & limits
Journalism and owner accounts
Cats · Television investigation
Owner accounts are important leads, but news coverage does not resolve an individual animal's medical cause. This report reflects information available in 2024.
Publisher article; regional access restrictions may apply
National reporting on pet arthritis antibodies
Reports on owner concerns about Librela and Solensia, veterinary uncertainty, and the manufacturer's safety response. Coverage includes both animals that benefited and suspected adverse outcomes.
Evidence & limits
Journalism and owner accounts
Dogs and cats · News report
A historical news report is context, not a clinical study or current label. Mixed-species reporting should not be read as a feline risk estimate.
Subscription may be required
Citizen Petition: where feline evidence appears
Pages 39–40 discuss a cat treated with frunevetmab in the joint-safety literature. The petition's formal requested actions focus on Librela (bedinvetmab) in dogs.
Evidence & limits
Advocacy submission
FDA-2026-P-6249-0001
The petition is a request for regulatory action and contains the petitioner's interpretations. It is not an FDA finding or an independent clinical study.
Open access · 88 pages
How FDA evaluated effectiveness
FDA explains its weight-of-evidence approach: although the confirmatory study did not meet its protocol-defined success criterion, the combined results supported effectiveness for osteoarthritis pain control.
Evidence & limits
Official assessment context
Cats · Solensia effectiveness
This describes FDA's approval reasoning. It does not establish joint repair or answer every long-term safety question.
Open access · See Solensia in “Flexibilities in the Review Process”
How to report a suspected adverse reaction
FDA explains how owners and veterinary professionals can report suspected animal-drug side effects and product problems, including submitting supporting information.
Evidence & limits
Practical reporting instructions
Owners and veterinarians · United States
An adverse-event report and a petition comment serve different purposes. Neither replaces veterinary assessment when a cat becomes unwell.
Open access
No matching sources
Try a different word, choose another topic, or clear the filters.
A curated reading guide, not a systematic review. This collection includes beneficial findings and safety concerns; it does not establish a complete safety profile. Source dates and access notes are shown above. External sources open in a new tab.
Cats are part of our advocacy
How the Citizen Petition
addresses cats
Filed June 1, 2026
FDA-2026-P-6249-0001
The petition includes feline evidence. Pages 39–40 discuss a published example of joint changes in a cat receiving frunevetmab and consider what that observation may mean for anti-NGF safety.
The scope matters: the formal actions requested in this filing focus on Librela in dogs. Its discussion of Solensia is part of the supporting evidence; it is not a separate FDA determination about cats or proof that the two medicines have identical risks.
Cat families can contribute relevant Solensia experiences and concerns through our comment hub. Describe what happened, what veterinary records show, and what remains uncertain.
A public comment supports the administrative record. Report a suspected reaction separately through the appropriate adverse-event reporting process.
For the people who love cats
Make the next conversation count
If your cat becomes unwell after treatment, contact your veterinarian promptly and discuss reassessment before the next planned injection.
Questions to bring to your veterinarian
- What findings support an osteoarthritis diagnosis in my cat?
- How do my cat’s health history and other medications affect the risks and expected benefit?
- Can we review the latest owner information sheet together?
- What changes should I record, and who should I contact if I notice them?
- How will we assess the response before another injection?
Document and report a concern
Keep a factual timeline: injection dates, health before treatment, other medicines, symptom onset, veterinary findings, and outcome. Retain records and product or batch details if available.
Use FDA’s instructions for U.S. reporting. If a report already exists, include its case number when sending follow-up information.
FDA reporting instructionsA suspected reaction can be reported even when the cause is uncertain. The regulator or manufacturer assesses the report.
Common questions
A few helpful distinctions
Is Solensia the same medicine as Librela?
They target the same protein, NGF, but contain different species-specific antibodies: frunevetmab for cats and bedinvetmab for dogs. Evidence from one species should not be treated as a direct measurement of risk in the other. See the petition's species context.
Does an adverse-event report prove the drug caused it?
No. Timing can raise suspicion, and patterns across reports can help identify signals. An individual cat may also have underlying disease, other exposures, or another explanation. Reports require clinical and regulatory evaluation. Read FDA's reporting caveats.
Can I calculate a death rate from report totals?
No. Report counts do not provide a reliable denominator of treated cats, and reporting can be incomplete or duplicated. A percentage of submitted reports is not a percentage of treated cats. See the FDA release.
Is a petition comment also an adverse-event report?
No. A petition comment enters the public regulatory docket; a suspected adverse-event report enters a drug-safety reporting process. Use the relevant route for each purpose. Comment hub · Reporting instructions
Your experience matters
For your cat.
For every cat family.
We welcome carefully documented experiences and corrections to this resource. If you share your cat’s story or photographs, let us know separately whether you consent to their publication.
Contact Paws Over Profits