Metacam vs Onsior
A detailed comparison of Metacam and Onsior for dogs. Which is the better choice? We compare ingredients, dosing, price, and side effects.
Metacam
Meloxicam oral suspension — the most widely prescribed long-term NSAID for canine osteoarthritis in the UK.
Onsior
Robenacoxib tablets — a newer, highly COX-2 selective NSAID. Often used for short-term peri-operative pain, but also licensed for chronic use in some countries.
Save on Metacam or Onsior at a UK pharmacy
UK registered pharmacies dispense the same prescription medications as your vet, often for less. Ask your vet for a written prescription, then fill it online.
Affiliate links to The Pharm Pet Co., a UK registered veterinary pharmacy. We may earn a small commission, at no extra cost to you. Always follow your vet's guidance on medication choice and dosing.
Side-by-Side Comparison
| Feature | Metacam | Onsior |
|---|---|---|
| Active Ingredient | Meloxicam | Robenacoxib |
| Form | Oral suspension | Tablet |
| Frequency | Once daily | Once daily |
| Species | Dogs | Dogs |
| Price Range | £12–£28/bottle | £15–£40/box |
Key Differences
COX-2 selectivity
Onsior (robenacoxib) is more COX-2 selective than Metacam (meloxicam), theoretically meaning fewer GI side effects.
Long-term use
Metacam has more extensive data for long-term arthritis management.
Clearance
Onsior has a short half-life — it clears the body faster, which is an advantage if side effects occur.
Cat use
Onsior is licensed for cats; Metacam has a cat formulation too but at different doses.
Cost
Metacam is cheaper, especially as generic meloxicam (Loxicom). No Onsior generic exists.
Pros & Cons
Metacam
Pros
- Decades of use — very well-understood safety profile
- Liquid form allows precise dosing
- Generic versions available (Loxicom) for savings
- Licensed for long-term use in dogs
Cons
- COX-2 preferential (not fully selective)
- Long plasma half-life — slower to clear if problems arise
- GI side effects in some dogs
- Must be given with food
Onsior
Pros
- Highly COX-2 selective — theoretically better GI safety
- Short plasma half-life — clears quickly
- Also licensed for cats (unique advantage)
- Well suited for peri-operative pain management
Cons
- More expensive than Metacam
- No generic version available
- Less long-term chronic use data than meloxicam
- Tablet form — less precise dosing for small dogs
Compare Prices & Save
Both Metacam and Onsior may be cheaper from a licensed online retailer than from your vet. Ask for a written prescription and compare prices.
Important: This comparison is for informational purposes only and is not veterinary advice. Always consult your vet before starting, stopping, or switching your pet's medication. Prices shown are typical UK ranges and may vary by product size, weight band, and retailer.
Alternative options to consider
Retailers we earn a commission from. It costs you nothing and never changes what we show.
The Pharm Pet Co. — Pet Pharmacy
UK online pet pharmacy. Flea, worm, prescription medications, supplements and pet food. Save vs vet prices.
Pet Care at Pharmacy2U
The UK's largest online pharmacy. Pet wormers, flea treatments, dental and joint care. Free delivery on orders over £30.
YuMOVE Joint Care for Dogs
The UK's number-one selling joint supplement for dogs. Triple action with green-lipped mussel, glucosamine and hyaluronic acid. Works in six weeks or money back.
We may earn a small commission if you purchase through these links, at no extra cost to you.