Onsior for Cats & Dogs

Onsior for Cats & Dogs
Cat 6mg » Priced per Tablet
Solution for Injection » 20mg/ml

Images are for illustration purposes only. Packaging may change from time to time and images on our website may or may not be updated.

  • Cat 6mg » Priced per Tablet £0.88
  • Dog 5mg » Priced per Tablet £0.63
  • Dog 10mg » Priced per Tablet £0.89
  • Dog 20mg » Priced per Tablet £1.25
  • Dog 40mg » Priced per Tablet £1.29
  • Solution for Injection » 20mg/ml £63.07

Selection of 6 products from

£0.63 to £63.07


Onsior is one of the safest medications of its type for use in cats and dogs. For dogs, it is used primarily to treat osteoarthritis (degenerative joint disease). It reduces pain and stiffness, increasing their mobility and enjoyment of exercise. Onsior can also be an effective treatment for the relief of pain and inflammation of other causes in both cats and dogs.

Onsior should not be given to animals which are dehydrated, or if underlying kidney or gastro-intestinal conditions might be present. Treatment should be suspended if vomiting or diarrhoea are seen.

Browse more prescription medication and cat and dog joint care.

Need help or advice? Contact us:

  • Landline: 01582 842096
  • Mon - Fri: 8:00am - 5:45pm
  • Sat: 9:00am - 1:00pm
  • Email: [email protected]

All prices include VAT where applicable.

Medication Datasheets

Reviews (60)

Summary of Reviews for Onsior for Cats & Dogs

Overall 5
Ease Of Use
Value For Money
Absence Of Side Effects
58 out of 60 (97%) customers would recommend this product.
5 stars (50 reviews)
4 stars (7 reviews)
3 stars (1 reviews)
2 stars (1 reviews)
1 stars (1 reviews)

Only verified purchasers of this product can leave a review.

35 Help for Cassie
Verified Purchase

By on 4 October 2021

Cassie has only just started taking Onsior so I do not know how effective it will be.

Customer recommends this product

45 a good buy
Verified Purchase

By on 13 September 2021

helped my dog almost immediately

Customer recommends this product

55 Anti inflammatory tablets for dogs with still joints
Verified Purchase

By on 18 August 2021

This was recommended by my vet - has really put the spring back into my spaniel's steps.

Customer recommends this product

55 Onsior for cats and dogs
Verified Purchase

By on 19 June 2021

Makes a difference to my dogs arthritis, seem to be more comfortable with his walking after taking a tablet

Customer recommends this product

55 Onsior..excellent product
Verified Purchase

By on 26 May 2021

Very effective

Customer recommends this product

Page 1 of 12

Next Page

Q & A

Below are some recent questions we've received regarding Onsior for Cats & Dogs, including answers from our team.

14 October 2021 at 8:04pm

What does do not give with food mean?

Pete Sutcliffe

  • VioVet customer since 2021
  • From: West Yorkshire, United Kingdom

The dosing instructions state this should not be given with food. Is there a time duration that this shouldn’t be given before or after food?

  • VioVet Staff

You should discuss the exact time period with your vet, however the datasheet states the following:

Do not administer with food since clinical trials demonstrated better
efficacy of robenacoxib for osteoarthritis when administered without
food or at least 30 minutes before or after a meal.

27 February 2021 at 2:30pm

Onsior and NAF products

Lizzie Cameron

  • VioVet customer since 2016
  • From: Cheshire, United Kingdom

Can naf canine relief be used with onsior ?

  • VioVet Staff

NAF Canine contains devils claw which does have anti-inflammatory properties. There is not enough research into devils claw to show how it does this so I do not recommend using them both together just in case they have a similar mode of action. If your dog is affected by arthritis then I advise using a joint supplement alongside the Onsior. I recommend reading our blog 'Arthritis in pets - prevention & management' for a useful guide on this.

27 July 2020 at 3:49pm

Changing regular dose time

Andrea Taylor

  • VioVet customer since 2015
  • From: Hertfordshire, United Kingdom

I currently dose in the evening but wish to change to morning. What is the safest way to achieve this? Should I miss a dose out then resume from morning.

  • VioVet Staff

You should never exceed your vet's recommended doseage with this medication, therefore it is safest to miss one dose (in the evening) then resume the following morning.

13 July 2020 at 11:55am

Onsior, dosage

Dorcas ODell

What is the correct dosage for a 22kg dog who has joint pain please.

  • VioVet Staff

Pasted below are the recommended doseages as found on the data sheet:

Number of Tablets by Strength and Body Weight for Osteoarthritis

Body Weight (kg) Number of Tablets by Strength
5 mg 10 mg 20 mg 40 mg
2.5 to <5 1 tablet
5 to <10 1 tablet
10 to <20 1 tablet
20 to <40 1 tablet
40 to 80 2 tablets

Number of Tablets by Strength and Body Weight for Soft Tissue Surgery

Body Weight (kg) Number of Tablets by Strength
5 mg 10 mg 20 mg 40 mg
2.5 1 tablet
>2.5 to <5 1 tablet
5 to <10 1 tablet
10 to <20 1 tablet
20 to <40 2 tablets
40 to <60 3 tablets
60 to 80 4 tablets
13 July 2016 at 2:22pm

Onsior or Previcox

Cherry Welsh

  • VioVet customer since 2015
  • From: Argyll and Bute, United Kingdom

I would be grateful if you could tell me if there is any significant difference between these 2 drugs regarding their safety and effectiveness in treating osteoarthritis.

My dog had Onsior for a few weeks and it didn't seem to make much difference.

With thanks

  • VioVet Staff

These are both effective normally at reducing the discomfort from osteoarthritis. I am not aware of any scientific investigations conducted to try and compare them in this way, but they are both generally regarded as about equally safe and effective based on anecdotal evidence. Some dogs might happen to respond better to one drug than another, but I do not think that is particularly likely. I would have to question if the symptoms you are noticing are genuinely caused by the osteoarthritis which has been identified. Obviously I cannot tell and indeed it might be very difficult to be sure, but I would say that sometimes osteoarthritis can exist without causing obvious trouble for the dog. Another, unidentified condition could be causing trouble now, rather than the osteoarthritis. My first suggestion would be to re-evaluate the diagnosis, which obviously means going back to your vet. If nothing else is identified, then perhaps just try a different drug as well as doing all you can in other ways to help. Joint supplements such as Yumove or Joint Force are widely believed to be able to help. It is also helpful to encourage regular, gentle exercise (but never excited, strenuous or prolonged). Weight loss through food reduction is for some dogs the most beneficial thing you can do, but that depends on the current bodyweight and other factors. All else being equal though, you aim for a slim dog. It is always possible through simply giving less food, but that is very difficult for many people in practice.

19 December 2015 at 9:55am



Can this be given at the same time as yumove?

  • VioVet Staff

It is very common to use a prescription, anti-inflammatory drug such as Onsior along with a non-prescription, joint supplement such as Yumove. Many vets do recommend this and it is safe. Other measures can involve restricting food levels a bit to help keep body weight down as well as encouraging regular but gentle exercise.

21 April 2015 at 9:02pm

Onsior overdose?

Gilly Peters

Hector is on constant Onsior, 1 tablet per day, but today we both inadvertently dosed him, so he has taken 2. Could this be dangerous? He seems hyper and a bit "whiney" (He is a 30kg Lab/lurcher).

  • VioVet Staff

This is unlikely to cause trouble, but it certainly could. If your dog shows any vomiting or diarrhoea it is important not to give any more tablets and go straight to your vet. If he seems fine then all should be well. I would be tempted to miss out the next dose though.

23 February 2015 at 2:20pm

Extra Tablets


Hello there
My dog has just been diagnosed with Elbow Dysplasia and has been given these Onsior tablets (40mg) to take.
We was wondering if we can also give him some herbal tablets too, as we gave him them before and seemed to help him, however we do not want any weird side effects.
Thank you for your help
Deanna Miller

  • VioVet Staff

Most herbal tablets appear to be safe and can be given alongside Onsior, but they have not all been tested and there is no scientific confirmation of that initial comment. Personally I would be happy for you to give any of the main brand herbal products at the recommended amount alongside Onsior. As long as your dog is otherwise well, it is very unlikely that there would be any sort of adverse reaction.The glucosamine/chondroitin based supplements, such as Joint Force, are regarded as particularly suitable to add to the treatment.

6 May 2014 at 11:00pm

Hair loss


My dog has been taking on onsior and is doing her leg good, can you please tell me if it has any side effects as she is losing her coat, it started with a lilltle bald patch on her back but now it's coming out on her chest
Please help
Thank you

  • VioVet Staff

Onsior can occasionally have side effects, but hair loss is very unlikely to be due to the Onsior. It is much more likely to be a coincidence that the hair loss is occurring at the same time. I would make sure that your flea control measures are adequate, even if you see no fleas, and take your cat to the vet to be checked out for any other causes. (A flea allergy would be a very common cause for hair loss on cats, and can happen with very few fleas which are difficult to see.)

Delivery Information