Melatonin is commonly used in dogs for short-term sleep disruption, mild situational anxiety (like fireworks), or certain coat/hair issues—but the right amount depends on your dog’s weight, the reason you’re using it, and what other meds they’re on. That’s why the safest approach is: use vet guidance first, and avoid “one-dose-fits-all” advice.
Before you give melatonin, check these safety points
- Avoid gummies and flavored chews unless your vet approves. Some products contain xylitol, a sweetener that can be dangerously toxic to dogs (can cause low blood sugar, seizures, liver injury).
- Pick plain melatonin tablets/capsules with the fewest extra ingredients.
- Don’t combine with other sedatives or new meds without veterinary advice.
General dose ranges vets commonly reference (not a substitute for your vet)
Different sources describe ranges in two common ways:
Weight-based guidance (example used by some experts):
- Around 0.1 mg per kg of body weight, sometimes repeated (e.g., every 8 hours) depending on the situation.
Size-based “typical” ranges you’ll often see:
- For sleep/anxiety, guidance commonly falls in the ~1–9 mg range depending on dog size and condition.
Because these ranges are broad, the safest move is to confirm a dose with your vet—especially for small dogs, seniors, dogs with liver disease, or dogs on other medications.
Side effects & red flags
Possible side effects include:
- Sleepiness, digestive upset, changes in behavior
Get urgent veterinary help if you notice:
- Vomiting, severe lethargy, collapse, tremors, seizures
- Or if your dog ate melatonin gummies / anything that might contain xylitol
