My dog ate Melatonin. What Should I do?

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Key Takeaways:

  • Melatonin is a relatively safe supplement.
  • Commonly used to calm or aid sleep in dogs, melatonin is also used to treat non-allergic alopecia in dogs.
  • Overdose of melatonin is rare, but symptoms tend to include vomiting, sleepiness, and lethargy.
  • Xylitol is sometimes used in human melatonin supplements, which IS TOXIC to dogs.

Many of us take melatonin or even give our pooch a melatonin supplement to assist with sleeping. 

Luckily melatonin is actually a very safe supplement, and the primary concern if your pooch eats human melatonin is the other ingredients that may be in the product that can cause problems. 

Xylitol is an artificial sweetener commonly used and is highly toxic to our fur babies. Read on to learn more about melatonin and your dog. 

How much melatonin is toxic to dogs?

Studies on melatonin in dogs are limited, and there’s no established toxic dose. We typically dose dogs 3mg per 12 hours when being given as a calming or sleeping aid in pooches.

Overdose can happen in small dogs eating a couple of human melatonin tablets or gummies at 10mg but luckily melatonin has a wide safety margin and your pooch would likely need to eat large quantities before significant signs are evident. 

There are anecdotal stories of dogs eating entire bottles of melatonin gummies without any ill effects. 

Melatonin is a very safe medication, and the most likely effect of an overdose is slight sedation, so there’s no reason to be too worried. 

What to do if my dog ate melatonin?

The first step if your dog ate melatonin is not to panic! Check the label to see what other ingredients may be in the product, specifically any that are toxic to our pooch dogs, such as xylitol. 

If there are any toxic or suspicious ingredients, then contact your veterinarian or the Pet Poisons helpline on (855) 764-7661 for advice and an appointment.

If there are no dangerous ingredients in the product, you can breathe a sigh of relief and focus on the melatonin. 

Melatonin is used in veterinary medicine and is a very safe medication, so even if eaten in large quantities slight sedation may be the only effect seen. You shouldn’t need to induce vomiting, and this is always safest done by your veterinarian due to the slight risk of aspiration of the vomitus. 

Your veterinarian is best placed to tell if your pooch has eaten sufficient amounts of melatonin for it to be of concern. 

Check the label for other ingredients that may be toxic to your pooch. Don’t panic, melatonin is a very safe medication used in veterinary medicine. Contact your veterinarian for specific advice about your pet and to find out if you need to induce vomiting. 

When to see a vet?

For the vast majority of dogs that eat melatonin, nothing is needed to be done, but it’s always a good idea to phone your vet for specific advice about your dog’s situation. Have to hand the amount your dog ate, the concentration of the tablets/gummies, and your dog’s weight, as this will help your veterinarian to ascertain if your pet has potentially overdosed. 

If your veterinarian feels that your pet has eaten an excessive amount for their bodyweight and enough for them to feel the effects of an overdose, then they may advise you to attend for an appointment to induce vomiting.

Most dogs that eat melatonin won’t need to be seen by a veterinarian, but if you’re unsure, you should phone your veterinarian for specific advice for your dogt’s situation. Information to have on hand is your dog’s weight, how much your pet ate, and the concentration of the tablets/gummies. 

What if my dog ate plenty of melatonin but seems fine?

Many dogs that eat melatonin suffer no ill effects due to its wide safety margin and your dog will likely feel fine even if they ate a large quantity of melatonin. It’s still advisable to read the label to check for other potentially dangerous ingredients to your dog in the product. If there are any, such as xylitol, then contact your veterinarian immediately for advice and an appointment. 

If there are no toxic ingredients and your dog is feeling fine, then there’s nothing to worry about. It’s no harm in phoning your vet for advice tailored to your dog’s situation specifically, but it’s unlikely that your pooch will need any intervention. Some dogs may experience slight sedation for 8-12 hours after eating a large amount of melatonin, but once you keep them warm and dry indoors, there shouldn’t be any lasting effects or concerns. 

It’s unlikely that your dog will suffer any ill effects from eating melatonin. As we mentioned before, it’s a safe medication and is used in veterinary medicine so that you can rest easy. Phone your vet for advice specific to your dog, particularly if they ate a huge quantity and they’re a small dog, but the main effect we see in cases of an overdose is slight sedation for up to 12 hours after eating melatonin. 

Signs that my dog ate melatonin

The most common side effect of your dog eating a large quantity of melatonin is slight sedation and sleepiness. This is harmless and shouldn’t be of major concern. If your dog experiences sedation, then it will last for up to 12 hours and may be of variable depth, but your pet should be rousable during this period, just a little sleepy and quiet. 

Some dogs experience vomiting or diarrhea, but these are mild and tend to resolve rapidly without any intervention. If vomiting or diarrhea persists or your pet is unresponsive or has a prolonged (>12 hours) period of sedation, then you should contact your veterinarian.

A few pets may have vomiting or diarrhea after eating melatonin, but the most common side effect is slight sedation and sleepiness. 

Final Woof

Melatonin is safely used in veterinary medicine for dogs with anxiety and behavioral and sleep disorders.

If your dog eats some of your human melatonin supplement then you should check that there are no dangerous substances, such as xylitol, within the product.

If your dog does eat a large amount of melatonin, then the most likely adverse effect seen would be slight sedation and sleepiness. A small number of dogs may also experience vomiting or diarrhea after eating melatonin supplements, but these are uncommon and generally self-limiting. 

If your dog eats melatonin, then you don’t need to worry as it’s very safe, but you can contact your vet for specific advice regarding your dog’s situation. Have to hand how much they’ve eaten, your dog’s weight and the concentration of the product they ate too. 

Photo of author
Since graduating from Dublin, Ireland in 2013 with an honors Veterinary Medicine degree, Edele has enjoyed working with as many species of animal as possible. Edele is currently working in clinical practice while studying towards Advanced Practitioner status with the RCVS in the UK. Passionate about education and writing, Edele’s goal is to maximize the pet-owner bond and welfare through education accessible to everyone. Never found without her middle-aged Weimaraner, Purdy (who still thinks she’s 18 months old), Edele spends her limited time outdoors with her horses, hiking and traveling home to Ireland to spend time with family.

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