Quick answer: some diabetic dogs do take joint supplements, but agree it with your vet before you start. Glucosamine is an amino sugar, so owners and vets reasonably ask whether it affects blood glucose. The honest answer is that the dog evidence is thin: a small, short study in healthy dogs found no change in a key blood sugar marker, but nobody has properly studied diabetic dogs. The bigger practical issue is often the chew itself, because a diabetic dog's food and treats need to be the same every day. If your vet is happy, show them the label of MedPaw Hip & Joint Chews and ask whether it suits your dog.
Transparency note: this page is written by MedPaw, which makes a joint supplement. It is general information, not a diagnosis or treatment plan, and it doesn't replace your vet's advice. Sources are linked so you can check them. Checked 9 October 2026.
Does glucosamine affect blood sugar in dogs?
The worry comes from laboratory and human research suggesting glucosamine could, in theory, make the body less sensitive to insulin. Here is what the canine evidence actually shows.
Glucosamine and blood glucose: what we know and what we don't
| Evidence | What it found | Its limits |
|---|---|---|
| Lenox and Lunn, JAVMA 2010: 12 healthy dogs, glucosamine-chondroitin vs placebo for 3 weeks | No significant change in serum fructosamine, a marker of average blood glucose over recent weeks | Healthy dogs only, small, short term |
| Studies in diabetic dogs | We could not find any | The question that matters most is unanswered |
| Human research | A review for GPs quotes a 2011 analysis finding no effect on fasting blood glucose or insulin sensitivity at oral doses | People, not dogs |
| VCA drug information | Lists insulin and other antidiabetic drugs among medicines to use with caution alongside glucosamine and chondroitin | A precaution, not evidence of harm |
Sources linked in the text below. Checked 9 October 2026.
The fructosamine study (Lenox and Lunn, Journal of the American Veterinary Medical Association, 2010) is described in a dvm360 research summary as a blinded crossover trial in 12 healthy dogs. The summary cautions that it doesn't prove there is no effect, because diabetic dogs handle glucose differently and any effect could, in theory, build up over time. As one veterinary commentary put it, this research "does not answer the question of whether glucosamine is safe for diabetic dogs". The human finding is from a review for GPs, and the medicine caution from VCA Animal Hospitals.
So we won't tell you glucosamine is risky for diabetic dogs, and we won't tell you it is proven safe. What it means in practice is simple: start only with your vet's agreement, and let them decide whether to check your dog's glucose or fructosamine a little sooner after starting.
Treats, calories and routine
PDSA's guide to diabetes in dogs explains that diabetic dogs need "the same amount and type of food every day" at set times, and that treats between meals should be avoided "because the extra food will cause a rise in blood sugar". It also notes that keeping your dog slim makes diabetes much easier to control.
- Give any chew with a meal, at the same time every day, never as a between-meals treat.
- Count it in the daily food, and ask your vet whether the meal needs a tiny adjustment.
- Keep it consistent. Don't start, stop or change several things at once, so your vet can see what changed if readings move.
- Use praise and play as rewards instead of food treats, as PDSA suggests.
When to see your vet
- Drinking or peeing more again, or accidents indoors
- Weakness, wobbliness, trembling or collapse, which can mean low blood sugar: follow your vet's emergency advice and call straight away
- Vomiting, not eating, or a missed meal on an insulin day
- Cloudy eyes or bumping into things
- New lameness, or stiffness that is getting worse
- Any change after starting a new supplement or chew
What helps a diabetic dog's joints
Steady routine helps both problems. Regular, similar daily exercise keeps joints moving and makes blood sugar more predictable, while sudden long hikes or rest days can push readings up or down. A lean body weight takes pressure off sore joints and helps diabetes control. Our guides to weight loss and joint supplements and low-impact exercise for stiff dogs have practical ideas, and non-slip rugs and a car ramp make daily life easier.
If your dog has arthritis pain, talk to your vet about pain relief. A supplement is not a painkiller. Our guide to what you can give a dog for joint pain covers the options vets use.
What to look for in a joint supplement
A 2022 review of 72 trials graded the common actives for dogs with arthritis:
How the main joint supplement ingredients compare on evidence for joint pain in dogs
| Ingredient | What the 2022 review of 72 trials found |
|---|---|
| Omega-3 (fish oil, green-lipped mussel) | The strongest evidence of the supplements reviewed |
| Glucosamine and chondroitin | Did not relieve pain |
| MSM, hyaluronic acid, Boswellia | Too few good trials to judge on their own |
Source: Barbeau-Grégoire et al., International Journal of Molecular Sciences, 2022.
For a diabetic dog that means omega-3 is worth asking about first. Fish oil adds calories, so your vet may want to account for it in the diet. Our guide to omega-3 fish oil for dogs' joints compares the options.
MedPaw's label, to show your vet
MedPaw doesn't treat diabetes or arthritis, and we don't claim it is suitable for every diabetic dog. It does contain glucosamine (170mg per chew), so the points above apply. Here is the full list of published actives and allergens:
MedPaw Hip & Joint Chews: the main amounts per chew on the label, to show your vet
| Ingredient or fact | Per chew, as published |
|---|---|
| MSM | 185mg |
| Glucosamine | 170mg |
| Chondroitin | 70mg |
| Green-lipped mussel | 70mg |
| Boswellia serrata | 30mg |
| Hyaluronic acid | Included (amount not published) |
| Vitamin C | 33mg |
| Vitamin E | 24 IU |
| Zinc | 3mg |
| Format | Soft chicken and bacon flavour chew, 60 per tub |
| Allergens | Mollusc (green-lipped mussel) and gluten (brewer's yeast) |
| What it is | A complementary feed, not a medicine or painkiller |
The full composition and analytical constituents are printed on the tub.
Our recommendation: get your dog's diabetes stable first, and keep insulin, meals and exercise on your vet's routine. If your vet agrees a joint chew can be added, MedPaw's soft chew can be given with a meal at the same time each day, and it comes with a 60-day money-back guarantee. Take the label above to your vet and ask whether MedPaw Hip & Joint Chews suits your dog. Feeding amounts by weight are on the product page.
For older dogs with stiff joints more generally, see the best joint supplements for senior dogs.
Joint supplements and diabetes: common questions
Is glucosamine safe for diabetic dogs?
It hasn't been properly studied in diabetic dogs. A small three-week study in healthy dogs found no change in fructosamine, and human research hasn't shown an effect on blood glucose at normal oral amounts. Start only with your vet's agreement, and let them decide whether to recheck glucose sooner.
Will a joint chew raise my dog's blood sugar?
Any food can, which is why diabetic dogs should have the same food at the same times every day and no treats between meals. Give a chew with a meal, at the same time daily, and ask your vet to count it in your dog's diet.
Can I give a joint supplement with insulin?
Many owners do, with their vet's agreement. VCA lists insulin among medicines to use with caution alongside glucosamine and chondroitin, so tell your vet before starting and report any change in your dog's thirst, appetite or energy.
What is the best joint supplement ingredient for a diabetic dog?
Omega-3 has the strongest evidence for joint pain in dogs and doesn't raise the glucosamine question, but fish oil adds calories. Your vet can advise on an amount that fits your dog's diet.
Should I tell my vet about my dog's supplements before a glucose curve?
Yes. Tell your vet about every supplement, chew and treat before any glucose curve or fructosamine test, so they can interpret the results properly.
My diabetic dog is stiff. Is it the diabetes or arthritis?
It could be either, or both, as weakness and stiffness have several causes in older dogs. Book a check with your vet rather than starting a supplement to find out.
