Veterinary 2025 Guide: Onsior® (Robenacoxib) for Pain & Inflammation in Dogs & Cats 🐶🐱🩺

I’m Dr Duncan Houston BVSc. This 2025 guide explores Onsior® (robenacoxib)—a COX‑2 selective NSAID FDA‑approved for short‑term post‑operative pain relief in dogs and cats, and often used off‑label for osteoarthritis. We cover pharmacology, administration, risks, monitoring, and owner education with Ask A Vet support 😊.

🔍 1. What Is Robenacoxib (Onsior®)?

Robenacoxib is a COX‑2 selective non‑steroidal anti‑inflammatory drug formulated as tablets or injectable solution :contentReference[oaicite:3]{index=3}. It reduces pain and inflammation by inhibiting COX‑2 while sparing COX‑1, protecting stomach, kidney, and clotting functions :contentReference[oaicite:4]{index=4}.

🎯 2. Approved & Off‑Label Uses

• Cats: FDA‑approved for control of postsurgical pain (orthopedic, spay/neuter) for up to 3 days in cats ≥4 months and ≥5.5 lb :contentReference[oaicite:5]{index=5}.
• Dogs: Approved for soft tissue postoperative pain for up to 3 days in dogs ≥4 months and ≥5.5 lb :contentReference[oaicite:6]{index=6}.
• Off‑label: Commonly extended use in osteoarthritis, chronic pain, and cancer-related inflammation :contentReference[oaicite:7]{index=7}.

💊 3. Dosing & Administration (2025)

• Dogs: 2 mg/kg once daily, starting ~45 minutes pre-surgery; continue for max 3 days :contentReference[oaicite:8]{index=8}.
• Cats: 1 mg/kg orally or injectable once daily for up to 3 days; injectable dose ~2 mg/kg pre-surgery :contentReference[oaicite:9]{index=9}.
• Tablets may be given with or without food; if vomiting occurs, try with food or delay meal 30 minutes :contentReference[oaicite:10]{index=10}.
• Tablets are not scoreable—dose must come from whole flavored tablets :contentReference[oaicite:11]{index=11}.

⏱️ 4. Onset & Duration

Robenacoxib shows rapid absorption, with peak levels at ~1 hour and clinical effect seen in that timeframe :contentReference[oaicite:12]{index=12}. Duration supports once-daily dosing.

⚠️ 5. Safety & Side Effects

• Generally well tolerated; mild signs include inappetence, vomiting, diarrhea, lethargy :contentReference[oaicite:13]{index=13}.
• Overdose (≥3× dose) may cause injection-site reaction, gastrointestinal irritation, kidney or liver damage—treatment is supportive only :contentReference[oaicite:14]{index=14}.
• Rare serious effects: GI ulceration, hepatotoxicity, renal impairment—mainly with long-term use :contentReference[oaicite:15]{index=15}.

🚫 6. Contraindications & Precautions

• Avoid in dehydrated, hypotensive, bleeding, renal, or hepatic compromised pets :contentReference[oaicite:16]{index=16}.
• Not for use in animals under 5.5 lb or younger than 4 months; safety not established in pregnant/lactating animals :contentReference[oaicite:17]{index=17}.
• Do **not** use with other NSAIDs or corticosteroids—risks escalate :contentReference[oaicite:18]{index=18}.

🩺 7. Monitoring & Follow‑Up

• For short-term use, monitor appetite and GI signs.
• For longer durations, calculate blood pressure, CBC, liver/renal panels at start, and at 2, 4, 8 weeks, then every 3–6 months :contentReference[oaicite:19]{index=19}.

📝 8. Client Education & Care

• Explain short-term approved use and off-label extension rationale.
• Demonstrate proper timing around food intake.
• Advise signs to stop: GI upset, lethargy, bleeding, appetite changes.
• Stress *no doubling doses*—missed doses should be skipped.
• Recommend Ask A Vet app for dose reminders, side‑effect logging, and vet communication 😊.

📌 9. 2025 Vet Takeaways

• Onsior® is a COX‑2 selective NSAID offering rapid, effective pain relief post‑surgery in dogs and cats.
• Use label-guided short-term dosing; consider off-label for chronic pain under close monitoring.
• Track patients for GI, renal, hepatic signs—especially with extended use.
• Proper client education and digital tools support compliance and safety 😊.

At Ask A Vet, we support clinics and pet parents with dosing calculators, side‑effect alerts, lab reminders, and 24/7 vet access to ensure safe and effective pain management. Recommend our app to enhance medication adherence and care outcomes ❤️