Prescribing overview
US feline tablets provide short-course postoperative analgesia, not an unrestricted chronic-pain regimen.
Key prescribing checks
- Assess hydration, kidney and liver disease and gastrointestinal history before NSAID treatment. Establish baseline evaluation and appropriate monitoring for the patient.
- Avoid concurrent NSAIDs or corticosteroids and assess appropriate switching intervals under the veterinarian’s plan.
- Vomiting, appetite changes, diarrhea or other suspected adverse effects require prompt veterinary contact. Continued discomfort after the labeled course requires reassessment and a revised analgesia plan, not automatic extension.
Uses by species
Approval and evidence apply to the named product, species, route and indication. An extra-label use requires its own prescribing assessment; a human indication is not an animal approval.
Cats
US FDA-approved Onsior tabletsPostoperative pain/inflammation with orthopedic surgery, ovariohysterectomy or castration
At least four months old and 2.5 kg.
Use / indication source ↗Pharmacology & pharmacokinetics
Mechanism and clinical role
Selective COX-2 inhibition was demonstrated in feline whole-blood assays; clinical relevance of those assay results is unestablished.
Absorption, distribution, metabolism and elimination
In cats, oral peak concentrations occur around 0.5 hours; terminal blood half-life averages 1.7 hours. Tissue persistence differs.
SAFETY REFERENCE · PRODUCT & SPECIES SPECIFIC
Contraindications & cautions
Contraindications identify circumstances where the source says a product should not be used. Precautions call for assessment or monitoring. Interactions identify combinations to review. They are distinct categories; this summary does not replace a full interaction check or the current product label.
Onsior
Oral tablets; Cats
Contraindications · when not to use
- Robenacoxib hypersensitivity or known NSAID intolerance.
Precautions & monitoring
- Assess renal, hepatic, cardiovascular and hydration status; QT prolongation is reported. Stop for poor appetite or lethargy.
Safety sources checked: . Selected label information; independent veterinary or veterinary-pharmacy review remains pending. A label for dogs, cats, horses or humans does not establish safety for another species.
Adverse effects
Vomiting, poor appetite and lethargy; NSAID-associated gastrointestinal, renal and hepatic injury can occur.
These are selected source-reported effects, not incidence estimates or an exhaustive list. Spontaneous postmarketing reports do not by themselves establish frequency or causality.
Dosing & administration
| Species & indication | Labeled regimen | Eligibility & source |
|---|---|---|
| CatsLabel-listed postoperative pain/inflammationOnsior 6-mg tablets | 2.5–6 kg: one whole tablet; 6.1–12 kg: two whole tablets Oral · Once daily Maximum three total doses over three days, counting injections | At least four months old; first dose approximately 30 minutes before surgery. Tablets must not be split. Verify full dosing label ↗ |
Nominal label dose is 1 mg/kg; use its whole-tablet chart. Injection has different dosing. Do not combine with NSAIDs/corticosteroids.
Extra-label prescribing and food-animal residue requirements are separate from labeled regimens. FDA extra-label-use guidance ↗
Drug & supplement interactions
This is a selected interaction reference, not an automated or comprehensive combination checker. Reconcile prescription drugs, nonprescription products, supplements and recent treatment changes.
Onsior
Oral tablets; Cats
- Do not combine with other NSAIDs or corticosteroids; assess washout. Avoid QT-prolonging drugs; monitor nephrotoxic combinations.
Monitoring
Baseline examination, blood counts/chemistry and hydration assessment; monitor appetite and postoperative comfort.
Client counseling
Stop and contact the veterinarian for appetite loss or lethargy; do not extend the course.
This section supports the veterinary team's discharge discussion; it does not replace the product’s Client Information Sheet where one is required.
Storage & handling
Store at 15–25°C; dispense with owner information.
Brands, formulations & ingredient identity
Active ingredients
Robenacoxib
Onsior identifies robenacoxib, not another NSAID. This entry verifies the US feline tablet product; formulations and approvals in other countries must be checked separately.
The tablet label limits total treatment to three days, including any in-hospital injectable or oral doses counted under its instructions.
Confirm species, age, weight, route and previous administration before dispensing. A brand match does not permit treating tablets and injections as independent courses.
Shared ingredients do not establish interchangeable concentrations, routes, release properties, species labeling or regional availability.
Onsior
- Formulation
- Oral tablets
- Label / product scope
- Cats
US feline postoperative product with age/weight eligibility and a three-day maximum course.
Product label / source ↗References & review status
Clinical reference updated October 16, 2026. Independent veterinary or veterinary-pharmacy review not yet completed. Evidence gaps remain explicitly identified; this page does not claim equivalence to a comprehensive, professionally reviewed veterinary formulary.
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