Onsior® Solution for Cats

An injectable NSAID used to control postoperative pain in cats. This page explains use, safety, and access so you can compare options. Available with US shipping from Canada.

What Onsior Is and How It Works

CanadianInsulin.com is a prescription referral platform. We verify prescriptions with your prescriber when required, and licensed Canadian pharmacies dispense your order.

Onsior® is a veterinary nonsteroidal anti-inflammatory drug containing robenacoxib. The Onsior Robenacoxib Solution is administered by subcutaneous injection to manage pain and inflammation after orthopedic procedures, spay, or castration in cats. It selectively inhibits cyclooxygenase-2 (COX-2), which may reduce prostaglandin production associated with pain and swelling while limiting effects on COX-1.

This medicine is intended for short-term use around surgery. The veterinarian administers the injection and monitors the patient during recovery. It is not labeled for dogs in the United States or Canada.

Who It’s For

Onsior Solution for cats is indicated for control of postoperative pain and inflammation. It is intended for individual patients a veterinarian has assessed as suitable for NSAID therapy. Do not use in animals with gastrointestinal ulcers, bleeding disorders, significant renal or hepatic disease, or known NSAID hypersensitivity. Avoid use during pregnancy or lactation unless the prescriber determines potential benefits outweigh risks. This treatment is not recommended for dogs under North American labels. For background on joint pain and mobility in companion animals, see Understanding Arthritis In Dogs And Cats What To Know.

Dosage and Usage

Dosing and duration follow the approved label and the veterinarian’s judgment. Typical perioperative use involves a single injection before surgery, with up to two additional once-daily doses if needed based on clinical response. Administration is subcutaneous only.

The Robenacoxib 20 mg/mL solution reference helps clinicians calculate an appropriate volume for each cat. Do not combine this therapy with other NSAIDs or corticosteroids. If the prescriber transitions the cat to an oral option, follow the approved instructions and avoid exceeding the labeled total duration for cats.

Strengths and Forms

Onsior Injection 20 mg/mL is supplied as a sterile multi-dose vial for veterinary use. Tablet forms with the same active ingredient exist for cats and for dogs; availability can vary by country and by clinic.

Missed Dose and Timing

If a scheduled injection visit is missed, contact the clinic to reschedule. Do not double up or compress dosing intervals. Keep postoperative checkups and monitoring appointments as directed by the veterinary team.

Storage and Travel Basics

Store the vial at controlled room temperature according to the package insert. Keep it upright in the original carton, away from moisture and excessive heat. Do not use product past the labeled in-use dating after first puncture; clinics track this carefully. Keep all medicines out of reach of children and animals.

When traveling, carry the prescription label and a copy of the veterinarian’s directions. Pack the vial securely to prevent breakage and keep it in a protective pouch during transit. For air travel, confirm airline rules for transporting veterinary medicines and be prepared to present documentation if asked. For additional reading on injectable products used in cats, see Baytril Injection For Cats Uses Dosage And Safety Guide.

Benefits

This treatment offers a parenteral option when a cat will not take tablets. It can be started at the time of anesthesia so pain control begins before recovery. COX-2 selectivity may lessen some gastrointestinal effects compared with older, less selective NSAIDs. Once-daily dosing can reduce handling stress in the early postoperative period.

Side Effects and Safety

• Vomiting or soft stool
• Reduced appetite
• Lethargy or behavior change
• Injection-site swelling
• Increased thirst or urination
• Elevated liver enzymes on lab testing

Serious but less common reactions can include gastrointestinal ulceration or bleeding, kidney injury, and severe dermatologic reactions. Stop therapy and seek veterinary care if the cat shows black stool, persistent vomiting, yellowing of the gums, or marked depression. Use cautiously in dehydrated patients or those with pre-existing renal, hepatic, or cardiac disease. Never use with another NSAID or a corticosteroid at the same time.

Drug Interactions and Cautions

Tell the prescriber about all medicines and supplements the cat receives. Interactions may occur with other NSAIDs, corticosteroids, anticoagulants, and nephrotoxic drugs. Extra care may be needed with diuretics or ACE inhibitors because kidney perfusion can be affected. Do not administer over-the-counter pain relievers unless specifically instructed by a veterinarian. For perioperative nausea topics, see Cerenia Tablets And Injections For Pets Uses And Dosage.

What to Expect Over Time

The cat should rest comfortably as anesthesia wears off, with gradual return to normal activity per veterinary instructions. This injection is intended for short-term use centered on a surgical event. If pain signs persist or worsen, contact the clinic for assessment. Ongoing monitoring through examination and, when indicated, lab tests supports safe use.

Compare With Alternatives

Veterinarians may consider another NSAID, such as Metacam Solution For Injection, for surgical pain control in selected patients. Where an oral route is preferred after surgery, meloxicam oral suspension for cats is another option; see Metacam Oral Suspension For Cats. Suitability differs by species, medical history, and lab results.

Pricing and Access

Pet owners can access Canadian pricing with US shipping from Canada through our pharmacy partners. Review current options on CanadianInsulin and submit your valid prescription to begin processing.

You can check live pricing for this medicine to estimate out-of-pocket spend. If comparing a cash-pay fill for a cat, look for the line item that matches the vial size needed. For recurring clinic purchases, request a written prescription so you can compare sources as appropriate.

See available offers on our Promotions page. For broader therapy choices, browse Pet Medications. Checkout is encrypted, and prescriptions are verified when required.

Availability and Substitutions

Stock can vary by supplier and by province. If a vial is unavailable, a prescriber may recommend an alternative NSAID or a different pain-management plan. Restock dates are not guaranteed. Any substitution should occur only under veterinary supervision with a clear clinical rationale.

Patient Suitability and Cost-Saving Tips

Good candidates include cats undergoing surgery who are otherwise healthy and well hydrated. Those with prior NSAID reactions, gastrointestinal disease, or significant renal or hepatic conditions may not be candidates. The prescriber will weigh potential risks and benefits on an individual basis.

To manage costs, request the smallest practical pack size that covers the intended short course. Coordinate refills early before scheduled dental or orthopedic procedures. You can set reminders in your account to upload a fresh prescription or approve a refill request ahead of time. Clinics may also use multi-dose vials; the veterinarian will determine appropriate quantities.

Questions to Ask Your Clinician

• Is the cat an appropriate candidate for this NSAID?
• What dosing schedule is planned around surgery?
• Which lab monitoring is recommended before and after use?
• Which medicines or supplements should be avoided?
• What warning signs should prompt a clinic call?
• How long should activity be restricted after surgery?
• Is transition to an oral option expected, and when?

Authoritative Sources

• FDA DailyMed: Robenacoxib Injection
• Health Canada Drug Product Database: Onsior (robenacoxib)
• Elanco: Onsior Veterinary Resources

Start your order at CanadianInsulin for licensed pharmacy dispensing and US shipping from Canada, with prompt, express shipping and temperature-controlled handling when required. Information here is educational and not a substitute for the approved label or veterinary advice.