Active ingredient
Robenacoxib for Animals: Mechanism, Doses by Species & Brands
Robenacoxib is a highly selective COX-2 inhibitor of the coxib class [1]. Under the US Onsior labels cats get 1 mg/kg by mouth once a day for up to 3 days [2], and dogs and cats get 2 mg/kg by subcutaneous injection once a day for up to 3 days [3].
- Drug class
- Non-steroidal anti-inflammatory drug (NSAID, coxib — highly COX-2 selective)
- Sourced doses for
- Cats, Dogs
- Brands on this site
- Onsior, Robenatail, SeamiCox
Robenacoxib dose calculator
Type the strength printed on your own product. Results are calculated in your browser from the cited doses on this page — always check the label of the product you use.
Robenacoxib dose by species
| Species | Use | Dose | Route | How often | Basis |
|---|---|---|---|---|---|
| Cats | Post-operative pain (tablets) Cats ≥ 2.5 kg and ≥ 4 months old. | 1 mg/kg[2] | PO | Once daily · Maximum 3 days | Label |
| Cats | Post-operative pain (injection) First dose about 30 minutes before surgery. | 2 mg/kg[3] | SC | Once daily · Maximum 3 days | Label |
| Dogs | Post-operative pain (injection) First dose about 45 minutes before surgery. | 2 mg/kg[3] | SC | Once daily · Maximum 3 days | Label |
What robenacoxib is used for
How robenacoxib works (mechanism of action)
NSAIDs reduce prostaglandin production by inhibiting the cyclooxygenase (COX) enzymes [1]. Robenacoxib is highly selective for COX-2 [1].
Safety, contraindications and precautions
Brands that contain robenacoxib
| Brand | Company | Contains | Market |
|---|---|---|---|
| Onsior | Elanco | Robenacoxib | USA (FDA label) |
| Robenatail | Vivaldis Health and Foods | Robenacoxib | India |
| SeamiCox | Drools Pet Food | Robenacoxib | India |
Frequently asked questions
What is the robenacoxib dose for cats?
Have a case in front of you?Ask WeVet — the AI assistant built for veterinarians. Differentials, treatment plans with calculated doses, drug info from trusted sources and SOAP notes.
Ask WeVet about thisMedically reviewed by
Dr. Ravi Baraiya, B.V.Sc.
Veterinarian · Reviewed 2 Nov 2026
References
- Nonsteroidal Anti-inflammatory Drugs in Animals
Passage read from this source
Robenacoxib is a coxib-class highly selective COX-2 inhibitor
Dosage is 2 mg/kg, PO, initially and then 1–2 mg/kg per day thereafter (for up to 6 days in cats).
NSAIDs act primarily to reduce the biosynthesis of prostaglandins by inhibiting cyclooxygenase (COX).
- ONSIOR (robenacoxib) 6 mg tablets for cats — FDA labeling
Passage read from this source
The dose of ONSIOR tablets is 0.45mg/lb (1mg/kg) orally once daily, for a maximum of 3 days.
Do not use in cats weighing less than 5.5 lbs, as cats less than 5.5 lbs cannot be accurately dosed.
ONSIOR has been shown to prolong the QT interval.
- ONSIOR (robenacoxib) injection — FDA labeling
Passage read from this source
0.91 mg/lb (2 mg/kg) subcutaneously once daily, for a maximum of 3 days
The first dose should be administered approximately 30 minutes prior to surgery
The first dose should be administered approximately 45 minutes prior to surgery
Do not administer ONSIOR injection or tablets in conjunction with any other oral or injectable NSAID or corticosteroid.
For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.