Is Melatonin Safe for Diabetic Dogs?

If your dog has Cushing’s disease, you might be wondering if melatonin is safe. For most dogs, the answer is yes, melatonin is generally safe and well tolerated. For dogs with diabetes, however, a potential change in blood sugar level is something to be aware of before giving this supplement.

It’s worth noting that most research on melatonin’s effect on diabetes involves humans or rodents, and results are conflicting. Some studies have found that melatonin can increase insulin resistance and raise blood sugar levels in diabetics, while others have found that it actually lowers blood sugar.

One of the few melatonin studies involving canines is referenced in a report by the European Medicines Agency. The study was limited in the sense that it used non-diabetic dogs as test subjects and gave them much higher doses of melatonin than normal. It’s relevant, however, because increased blood sugar levels were observed at some time points during the six months of testing. This lends some weight to the idea that melatonin may promote insulin resistance in dogs.

Everything considered, caution is advised for anyone who is contemplating giving melatonin to their diabetic pet. We strongly suggest consulting your veterinarian before administering any supplement.

Please note, when purchasing melatonin, make sure it does not contain xylitol. Xylitol is an artificial sweetener that is extremely toxic to dogs. Extended and rapid release formulas are also not recommended.

References

Assessment Report for Circadin, by European Medicines Agency (see page 11)

Can You Give a Dog Melatonin? Here’s What to Know, by Brittany Grenus, DVM

Effects of melatonin supplementation on blood glycemic indices in adults: a GRADE assessed systemic review and dose response meta-analysis of randomized controlled trials.