If your dog has been prescribed Cartrophen, or your vet has mentioned it, you may be wondering where a daily joint supplement fits in. It is a fair question, and one many owners ask once joint trouble has been diagnosed. The short answer is that the two do very different jobs.
Cartrophen is a prescription-only veterinary medicine given by a vet. A joint supplement is a complementary feed given daily as part of your dog's routine. Here we explain the difference in plain English, what the manufacturer says about how a Cartrophen course works, and why any decision about combining the two belongs with your vet.
Some of the information online comes from outside the UK, and schedules and licensing can differ by country. Please use this as background for a conversation with your own vet, not as a replacement for their advice.
Comparing joint supplements before you speak to your vet
Once Cartrophen is part of your dog's plan, the supplement question comes down to what is actually on the label. The table below sets out six UK joint supplements, including MedPaw Hip & Joint Chews Max, which is our own product, so you have clear ingredient lists to hand.
Your vet decides what sits alongside a prescribed medicine, so treat this as a reference sheet for that conversation. It is not a green light to add anything new on your own.
MedPaw is the only one of the six with all six key joint actives
| Ingredient | MedPaw Hip & Joint Chews Max | NutraPaw Joint Support | YuMOVE Joint Support PLUS Max | Seraquin Joint | Synoquin EFA | Nutraquin+ |
|---|---|---|---|---|---|---|
| Key joint actives | 6 of 6 | 4 of 6 | 3 of 6 (+1 via mussel) | 2 of 6 | 2 of 6 | 3 of 6 |
| Glucosamine | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Chondroitin | ✓ | ✗ | Via mussel | ✓ | ✓ | ✓ |
| MSM | ✓ | ✓ | ✗ | ✗ | ✗ | ✗ |
| Green-lipped mussel | ✓ | ✓ | ✓ | ✗ | ✗ | ✗ |
| Hyaluronic acid | ✓ | ✓ | ✓ | ✗ | ✗ | ✗ |
| Boswellia | ✓ | ✗ | ✗ | ✗ | ✗ | ✓ |
| Omega-3 | Mussel, flax | Mussel | Mussel, fish oil | ✗ | Krill oil | ✗ |
| Turmeric | ✗ | ✓ | ✗ | ✓ | ✗ | ✗ |
| Collagen | ✗ | ✓ | ✗ | ✗ | ✗ | ✗ |
| Antioxidants | Vit C, Vit E, zinc | Manganese | Vit C, Vit E, manganese | ✗ | Vit C, zinc | Vit C, zinc |
| Format | Soft chew | Tablet | Tablet | Chewable tablet | Tablet or capsule | Capsule |
| Guarantee | 60 days | 90 days | 6 weeks | Not stated | Not stated | Not stated |
✓ = included, ✗ = not listed. Key joint actives: glucosamine, chondroitin, MSM, green-lipped mussel, hyaluronic acid and Boswellia. Taken from each manufacturer's published information, September 2026.
The top row is the useful one. MedPaw is the only product of the six with all six key joint actives: glucosamine, chondroitin, MSM, green-lipped mussel, hyaluronic acid and Boswellia serrata. NutraPaw scores 4 of 6, YuMOVE and Nutraquin+ 3, and Seraquin and Synoquin EFA 2 each.
For a dog on injections, that matters because one product with the full set means one label for your vet to review, rather than a stack of separate additions. It also makes it easier to introduce a single change at a time, which is the sensible way to add anything to a dog's routine.
MedPaw is a daily soft chew, a complementary feed that supports joints, mobility and comfort alongside veterinary care, never in place of it. It also contains omega-3, vitamins C and E and zinc. There is a 60-day money-back guarantee, and Subscribe & Save is available.
See the MedPaw Hip & Joint Chews Max label Read the full ingredient list and feeding guide, then take it along to your next appointment so your vet can advise on what suits your dog.
What Cartrophen is, and what it is not
Cartrophen contains pentosan polysulfate sodium (100mg/mL). It is an injectable, sulphated sugar of plant origin, derived from beechwood, so it is not made from animal products. A vet must assess your dog before it can be given.
The manufacturer classes it as a disease modifying osteoarthritis drug, often shortened to DMOAD. It says the medicine acts at several points in the underlying processes of arthritis, including preserving joint cartilage.
It is given by injection under the skin, in a similar way to a vaccination. That is very different from a chew or tablet in your dog's bowl, which is why the two should never be treated as interchangeable.
A supplement is never an alternative to veterinary treatment. Cartrophen is prescribed after a vet has diagnosed a joint problem. A supplement supports everyday joint care alongside that.
How a Cartrophen course works
The course itself
A standard course is four injections, one every 5 to 7 days. The manufacturer stresses that all four should be completed for the intended benefit, so it helps to put the dates in your diary at the start.
Some clinics time the course around the annual vaccination and check-up. This can mean the later injections are nurse appointments after the vet's initial assessment. It is reasonable to ask your practice whether that could work for your dog.
Repeat courses and monitoring
The manufacturer's guidance is that each treated dog needs at least one full course a year. Frequency ranges from once a year for mild cases to up to three times a year for severe cases. One veterinary clinic describes some dogs with more significant joint changes having two courses a year, or monthly maintenance injections. Your vet may adjust the plan for your individual dog.
Once osteoarthritis has been diagnosed, the manufacturer recommends a check-up at least every six months. This helps your vet track progress and choose the best time to repeat treatment.
What to expect
The manufacturer says many dogs respond quickly to the initial course, with less lameness and pain and more activity. That is the manufacturer's own view, not independent evidence, so treat it as one data point. A veterinary clinic notes that results can be gradual and may take a few weeks to become noticeable.
The manufacturer also says veterinary experience suggests a clinical response generally lasts 3 to 12 months and varies from dog to dog. Vets also commonly use it once the sutures are out after joint or ligament surgery, but that is always the vet's decision.
One veterinary clinic describes side effects as rare and the medicine as well tolerated. No medicine comes with promises, though, so do talk through the risks with your own vet.
A prescription medicine and a joint supplement do different jobs
| Question | Cartrophen | Daily joint supplement |
|---|---|---|
| What is it? | Prescription-only veterinary medicine | Complementary feed |
| Who decides on it? | Your vet, after assessing your dog | You, ideally after checking with your vet |
| How is it given? | Injection under the skin, usually a course of four | Daily, by mouth, as part of the routine |
| What is its role? | Veterinary treatment of diagnosed joint disease | Nutritional support for everyday joint care |
| Can it replace vet care? | It is part of vet care | No, it sits alongside it |
For guidance only, not a diagnosis.
Can a joint supplement be used alongside Cartrophen?
The sources give two views, and both are worth hearing.
- The manufacturer's view: nutraceuticals such as glucosamine and chondroitin sulphate are nutritional rather than therapeutic products, and they usually need daily consumption. The manufacturer also says that with a good balanced diet, a nutritional supplement is not necessary.
- A veterinary clinic's view: Cartrophen can be used alongside joint supplements, newer monoclonal antibody pain treatments, dietary changes and exercise management. The clinic describes a combined plan as helpful for many pets.
So there is no single rule. Whether a supplement makes sense depends on your dog's diagnosis, diet and medication, and your vet knows those best. If you would like to add one, ask before you start rather than after.
A key caution about painkillers
This is the part of the manufacturer's guidance that owners most often miss. Non-steroidal anti-inflammatory drugs (NSAIDs) are generally considered safe to use at the same time as Cartrophen. However, the manufacturer recommends they are not used concurrently because of their differing modes of action.
There is a second reason for care. Pain relief from an NSAID can make a dog much more active, much sooner than the joint's recovery warrants. Returning to vigorous exercise too early can aggravate the problem. If your dog needs immediate pain relief, the manufacturer suggests a different type of painkiller may be a better choice, and that is your vet's call.
- Never give your dog human painkillers or leftover medication.
- Ask your vet which pain relief is appropriate for your dog.
- Ask how much exercise is sensible during and after a course, and stick to it even if your dog seems brighter.
Supporting your dog's joints day to day
Whether or not your dog is on Cartrophen, the everyday basics matter. None of these replace veterinary care, but they fit comfortably alongside it.
- Keep to the exercise plan. After a course of injections or surgery, follow your vet's advice on lead walks, rest and building activity gradually.
- Feed a balanced diet. Good nutrition is the foundation, as the manufacturer itself points out.
- Manage weight. Extra weight puts extra load on joints, so ask your vet to check your dog's body condition.
- Make the home easier. Non-slip rugs on hard floors, a supportive orthopaedic bed, and ramps or steps for the car or sofa can all help a stiff dog.
- Consider a daily supplement if your vet is happy. Supplements are about nutritional support, and consistency matters because they typically need daily use.
Where MedPaw fits
MedPaw Hip & Joint Chews Max is a daily soft chew and a complementary feed for dogs. It supports everyday joint care as part of your dog's routine. It does not diagnose, treat or replace veterinary care, and if your dog is on Cartrophen or any other medication, please check with your vet first.
The key joint actives are glucosamine, chondroitin, MSM, green-lipped mussel, hyaluronic acid and Boswellia serrata. It also contains omega-3 from green-lipped mussel and flax seed, vitamins C and E, and zinc, and it is made with rapeseed oil and glycerine.
Feeding guide
- Up to 4kg: 1 chew a day
- 5 to 17kg: 2 chews a day
- 18kg and over: 2 to 3 chews a day
The amount is doubled for the first three weeks, and daily use for 2 to 3 months is recommended. If your dog sits between weight bands, follow the guidance on the pack. There is a 60-day money-back guarantee, and Subscribe & Save is available.
When comparing any joint supplement, look at the format as well as the ingredient list. Joint products come as tablets, chewable tablets, capsules and soft chews. A dog who dislikes tablets may find a soft chew easier to take, but that is a matter of preference, not a claim about results.
When to see your vet
Joint changes can creep up slowly, so it helps to know what is worth a phone call. Book an appointment promptly if you notice any of the following:
- Limping, favouring a leg, or sudden lameness
- Stiffness after rest that does not ease, or difficulty getting up
- Reluctance to jump, climb stairs, go for walks or play
- Yelping, crying, snapping when touched, or licking or chewing at a joint
- A swollen, warm or visibly misshapen joint
- Muscle loss in the back legs, or a change in the way your dog sits or walks
- Changes in appetite, mood or sleep that may suggest ongoing discomfort
How quickly should you call the vet?
Brighter, and keen to do more
Ask your vet before increasing exercise, or before starting or changing a supplement while your dog is on prescribed medication.
Signs returning, or no improvement
If stiffness or lameness comes back sooner than expected, your vet may adjust the plan or the timing of repeat treatment.
Cannot put weight on a leg, collapses, or seems in severe pain
Seek urgent veterinary advice straight away.
Bringing it together with your vet
Cartrophen and a daily joint supplement are not rivals. One is a veterinary medicine prescribed for a diagnosed problem, and the other is nutritional support that sits alongside your dog's routine. Neither is a substitute for a proper assessment.
The most useful step is a conversation about the whole joint-care plan: diet, weight, exercise, pain relief and any supplement. Take a list of what your dog currently eats and takes, including chews and treats, so your vet can see the full picture and advise what suits your dog.
Can I give my dog a joint supplement while they are having Cartrophen injections?
There is no single rule, and I cannot say it is right for your dog. Cartrophen is a prescription veterinary medicine and a joint supplement is a complementary feed, so they do different jobs. One veterinary clinic describes Cartrophen being used alongside joint supplements, but the decision belongs with your vet, who knows your dog's diagnosis, diet and other medication. Please ask before you start.
Is there any published interaction data for glucosamine or chondroitin with Cartrophen?
The manufacturer describes glucosamine and chondroitin as nutritional rather than therapeutic products that usually need daily use. I am not aware of published interaction data for the other common joint actives, such as green-lipped mussel, MSM, hyaluronic acid, boswellia or omega-3, given alongside Cartrophen. Where there is no data, it is best to say so plainly and let your vet weigh it up for your dog.
Should I start a supplement and Cartrophen at the same time?
It is usually sensible to introduce one change at a time, so you and your vet can see how your dog is getting on with each. Ask your vet whether they would prefer you to wait until the course of injections is complete before adding anything new. Keep a note of the dates and any changes you notice, and share it at the next check-up.
What should I ask my vet before adding a joint chew?
Take the product label with you and ask whether anything in it is a concern for your dog's diagnosis, diet or current medicines. It is also worth asking about pain relief, as the manufacturer advises against using NSAIDs at the same time as Cartrophen, and about how much exercise is sensible during and after the course. Your vet can then advise on timing and whether a supplement suits your dog.
How many MedPaw chews would a 20kg dog have, and how long does a tub last?
Under the printed label, a dog of 18kg and over has 2 to 3 chews a day, doubled for the first three weeks. At 20kg that is 4 to 6 chews a day for the first three weeks, then 2 to 3 a day after that. A tub holds 60 chews, so it lasts roughly 10 to 15 days at the starting amount, then 20 to 30 days at the standard amount. The label recommends 2 to 3 months of daily use, and please check with your vet first if your dog is on Cartrophen.
Can a joint supplement replace Cartrophen injections?
No. Cartrophen is prescribed by a vet for a diagnosed joint problem, and a supplement such as MedPaw Hip & Joint Chews Max is a complementary feed that supports everyday joint care. It sits alongside veterinary treatment, never instead of it. If your dog is limping, stiff or seems uncomfortable, please speak to your vet.
