Speak to a vet within minutes

4.9 On the App Store 3600+ reviews

Pet Medication 101: Onsior

Onsior for dogs and cats

It’s important to understand a medication’s uses and side effects before giving it to your pet. This medication info sheet is meant to give you a good understanding of what Onsior (robenaxocib) is used for, how it works, and potential side effects in cats and dogs. Always consult a veterinarian before giving your pet any medication.

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

  • Professional vet advice online
  • Low-cost video vet consultations
  • Open 24 hours a day, 365 days a year

1. Drug Name:

Robenacoxib

2. Brand Name:

Onsior

3. How Dispensed:

Prescription-only

4. Forms:

5mg, 6mg, 10mg, 20mg, 40 mg tablets

20mg/mL injectable solution

5. Drug Type/Class:

Non-steroidal anti-inflammatory drug (NSAID)

6. Uses in Dogs and Cats:

Onsior is used to control pain and inflammation that is associated with surgery and musculoskeletal disorders such as osteoarthritis and fractures.

7. How it Works:

Robenacoxib blocks the enzyme (protein that increases the rate of a chemical reaction) cyclooxygenase (COX-2). Blocking this enzyme decreases the production of prostaglandins that causes the pain and swelling of inflammation and other conditions. Inhibiting COX-2 provides anti-inflammatory, pain relief, and can decrease fever.

8. Side Effects and/or Signs of Overdose:

Gastrointestinal side effects are common and can occur in 10% of dogs and cats. These side effects include vomiting, soft stool to diarrhea, decreased appetite, and blood in the stool. Some pets may have a decrease in energy levels. Elevated liver enzymes are common in dogs on long-term robenacoxib.

Overdosage can cause gastrointestinal upset and adverse effects on the kidney. Gastrointestinal ulceration can occur which can cause perforation (development of a hole) in the stomach or intestine. This can lead to infection and inflammation in the abdomen (peritonitis) or throughout the entire body (sepsis).

9. Drug Interactions:

  • Corticosteroids and other NSAIDs increase the risk of gastrointestinal toxicity
  • Aminoglycoside antibiotics (such as gentamicin or amikacin) may increase the risk of kidney toxicity
  • Furosemide
  • Cimetidine
  • Insulin may increase the risk of hypoglycemia
  • Cyclosporine
  • Methotrexate
  • Aspirin and clopidogrel increase the risk of bleeding

10. Cautionary Statements:

  • NSAIDs should only be used in animals that are otherwise healthy. Do not use in patients who are dehydrated or have impaired heart or kidney function
  • Animals should be closely monitored, and clients should be advised of the clinical signs of, side effects of NSAIDs
  • Risk factors for side effects include: disease of the liver, gastrointestinal tract, and kidney
  • Liver injury may occur with robenacoxib
  • Bloodwork is recommended before starting an NSAID and monitoring liver and kidney bloodwork if being used long term
  • Contraindicated in pregnant and lactating animals

Read more:

Signs of Pain in Dogs

Signs of Pain in Cats

Arthritis in Dogs

Need to speak with a veterinarian regarding your pet's medication or another condition?

Click here to schedule a video consult to speak to one of our vets. You can also download the FirstVet app from the Apple App Store and Google Play Stores

More articles about dog

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

Get started
  • Low-cost video vet consultations, 24 hours a day Low-cost video vet consultations, 24 hours a day
  • Experienced, licensed vets Experienced, licensed vets
  • Over 700,000 satisfied pet owners Over 700,000 satisfied pet owners