VETINUITY
Why does robenacoxib work for 24 hours when its plasma half-life is short?
It is acidic and concentrates in inflamed tissue, where it persists well after plasma levels fall, which is why once-daily dosing holds.
● ANSWER
Sourced & dated
What is the robenacoxib dose for dogs and cats?
Robenacoxib is 2 mg/kg SC once daily in dogs and cats, or tablets once daily (2 mg/kg in dogs, 1 mg/kg in cats), for a short label course starting before surgery.
● VETINUITY ROBENACOXIB DOSE CALCULATOR
Vetinuity robenacoxib dose calculator
Injection is 20 mg/mL. Cat tablet is 6 mg; dog tablets 5, 10, 20 and 40 mg.
● WHAT'S DOCUMENTED
Per Vetinuity’s robenacoxib dose table, dogs and cats get 2 mg/kg subcutaneously once a day, or tablets once a day (about 2 mg/kg in dogs, one 6 mg tablet for a 2.5 to 6 kg cat), with the first dose before surgery and a US label limit of 3 days. The calculator above shows the injectable volume from the 20 mg/mL vial.
Robenacoxib doses by indication
| Indication | Dog | Cat | Route and frequency |
|---|---|---|---|
| Postoperative pain and inflammation, soft tissue surgery | 2 mg/kg SC, or 2 mg/kg PO | 2 mg/kg SC, or 1 mg/kg PO (6 mg tab) | q24h, up to 3 days (US) |
| Orthopedic surgery (cats, label) | not applicable | 2 mg/kg SC then tablets | q24h, up to 3 days (US) |
A COX-2 selective coxib that stays in tissue
Robenacoxib is among the most COX-2 selective NSAIDs in veterinary use, and its short plasma half-life is offset by persistence in inflamed tissue. The 2022 pharmacology review by Lees and colleagues summarizes how that tissue selectivity supports once-daily dosing and a rapid washout from blood, which can be convenient when changing analgesic plans. For cats, robenacoxib and meloxicam are the two NSAIDs most clinics reach for.
Contraindications and cautions
Do not combine with corticosteroids or another NSAID; allow a washout when switching. Avoid in dehydrated, hypotensive or hypovolemic patients, and in animals with kidney disease, GI ulceration or bleeding disorders. Give tablets without food or with a small amount, as the label directs, and do not split the tablets, which are not scored. The cat label lower limits are 2.5 kg and 4 months; the dog label lower limits are 2.5 kg and 4 months.
Longer courses in cats
King and colleagues treated cats with chronic musculoskeletal disease with robenacoxib for weeks and reported a safety profile similar to placebo, including in cats with stable chronic kidney disease. That supports careful extended use with monitoring, but it is not the US label. This dose table is published by Vetinuity, the clinical assistant from emergency veterinarian Brian Toncray, DVM.
Related: meloxicam, carprofen, NSAID overdose and buprenorphine.
● SOURCES
- 1. DailyMed: Onsior (robenacoxib) label search. Dosage and administration; contraindications. Checked 2026-10-26.
- 2. Lees P, Toutain PL, Elliott J, et al. Pharmacology, safety, efficacy and clinical uses of the COX-2 inhibitor robenacoxib. J Vet Pharmacol Ther. 2022;45(4):325-351. PMID 35460083. Tissue selectivity; dosing. Checked 2026-10-26.
- 3. King JN, Seewald W, Forster S, et al. Clinical safety of robenacoxib in cats with chronic musculoskeletal disease. J Vet Intern Med. 2021;35(5):2384-2394. PMID 34196973. Results. Checked 2026-10-26.
● RELATED ANSWERS
- Meloxicam Dose for Dogs and Cats (Metacam)
Meloxicam is dosed at 0.2 mg/kg once, then 0.1 mg/kg once daily in dogs; in US cats the label allows a single 0.3 mg/kg SC injection only, while some other countries label 0.05 mg/kg PO daily long term.
- Carprofen Dose for Dogs and Cats (Rimadyl)
Carprofen is dosed at 4.4 mg/kg once daily or 2.2 mg/kg twice daily, PO or SC, in dogs; it is not labeled for cats in the US, and some other countries label only a single 4 mg/kg perioperative injection in cats.
- Ibuprofen and NSAID Overdose in Dogs: Toxic Doses
Ibuprofen causes GI signs in dogs from 100-125 mg/kg, renal failure from 175-300 mg/kg, CNS signs above 400 mg/kg and can be lethal above 600 mg/kg; naproxen is toxic at far lower doses.
- Buprenorphine Dose for Dogs and Cats (Simbadol)
Buprenorphine is dosed at 0.01-0.02 mg/kg IV or IM every 6-8 hours in dogs and 0.01-0.03 mg/kg IV, IM or oral transmucosal every 6-8 hours in cats, with the 1.8 mg/mL Simbadol formulation at 0.24 mg/kg SC once daily in cats only.
- Omeprazole Dose for Dogs and Cats
Omeprazole is dosed at 1 mg/kg by mouth every 12 hours in dogs and cats, given 30-60 minutes before a meal, and tapered rather than stopped after courses longer than 3-4 weeks.
● FAQ
Can robenacoxib be used long term in cats?
The US label course is short. A clinical safety study of cats with chronic musculoskeletal disease treated for longer found it well tolerated, and some other countries allow longer use, but in the US that is extra-label.
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