4 min read


Can Dogs Overdose on Melatonin?



4 min read


Can Dogs Overdose on Melatonin?


From hair loss and alopecia to insomnia and separation anxiety, there are many reasons why your veterinarian might prescribe melatonin to your dog. This naturally-occurring hormone is created by the pineal gland in dogs and humans, and it's becoming increasingly commonly used to treat a wide range of doggy medical conditions.

While there's minimal scientific evidence regarding the use of melatonin in dogs, it's generally regarded as being safe to give to our canine companions. However, it's important to get the dosage just right, as an overdose of melatonin could have very serious consequences for your dog.

The correct melatonin dosage for your dog varies depending on a number of factors, so ask your vet whether it's safe to give melatonin to your dog and, if so, how much they should have.


Signs and Symptoms of a Melatonin Overdose

While melatonin can have plenty of potential benefits to help your dog overcome a variety of health and behavioral problems, it's also possible for your pet to have too much of a good thing. Make sure to work out the correct dosage for your pet with your vet, as this will eliminate the risk of overdose.

However, if you're worried you may have given your dog too much melatonin, or if you think they may have gotten into the medical supplies and helped themselves to an extra dose, make sure you recognize the warning signs and know how to respond. In the case of a mild overdose, the symptoms are unlikely to be overly dramatic. Your pet may have a slightly upset stomach, for example, and also show signs of sleepiness.

Significant overdoses can produce much more serious symptoms and require an urgent response. Signs to keep an eye out for include vomiting and diarrhea, loss of coordination, high blood pressure, and even seizures.

If you notice any of these symptoms, don't delay. Contact your vet immediately or call a poison control hotline. You'll be advised on the best next steps and what you can do to look after your pet.

Body Language

Keep a close eye on your dog's body language for any cues that may indicate an overdose of melatonin, such as:<br/>

  • Weakness
  • Sleepiness

Other Signs

Other signs you may notice include:<br/>

  • Vomiting And Diarrhea
  • Seizures
  • Loss Of Coordination
  • Confusion
  • High Blood Pressure


The Science of Melatonin's Affects on Dogs


Unlike many of the other medications that may be prescribed to your dog throughout their life, melatonin isn't a drug that was invented in a lab by people in white coats. Rather, melatonin is a hormone secreted by the pineal gland, which is located in the center of the brain.

As production of the hormone is inhibited by daylight, it only takes place at night, and as a result, it plays an important role in regulating your dog's internal clock. And because the hours of daylight vary throughout the seasons, your dog's melatonin levels will also fluctuate. These seasonal changes have an impact on the reproductive system, while melatonin also affects thryoid function and immune function.

Therapeutic use of melatonin in humans first gained widespread attention in the 1990s, mainly to combat jetlag and insomnia, but the hormone's calming effect also saw researchers begin to consider using it to treat other conditions.

In dogs, melatonin can be prescribed to help treat a variety of conditions, including:

  • To control sleeping patterns, for example in older animals suffering from the disrupted sleeping patterns caused by sundowner syndrome
  • To treat various kinds of anxiety, including separation anxiety
  • To promote hair growth, for example in a dog suffering from hair loss due to alopecia
  • To combat a range of phobias
  • To help dogs gain weight after an illness or after undergoing surgery

Giving Your Dog Melatonin


Melatonin for dogs can be given as pills, capsules, chewable tablets, powders, drops, and even can be injected as a subcutaneous implant. When taken orally, it can be plain or offered with a tasty flavor likely to encourage canine consumption.

Once given, it is quickly absorbed into the bloodstream, taking effect within 15 to 20 minutes, but we actually know surprisingly little about how it goes to work on your dog. In fact, there's very little scientific evidence on the use of melatonin in dogs, which is something every dog owner should be aware of before giving it to their pet.

If you live in the US and Canada, the drug is available over the counter, but its supply is more strictly controlled in other parts of the world. However, before you start giving your dog melatonin, make sure you consult your vet.

Your veterinarian is qualified to determine whether or not your dog could benefit from melatonin. While the drug is widely considered to be a safe option for most dogs, there could be other factors at play that could limit its suitability for your pet. For example, if your dog is already on other medications, they could potentially react with the melatonin. The drug should also never be given to pregnant animals or puppies under 12 weeks of age.

Side effects are rare but have been known to occur in some cases, so your vet will run you through the pros and cons of giving melatonin to your pet.

As for the correct amount to give your pet, and for how long to continue administering melatonin, this should once again be left up to your vet. From the condition affecting your dog to their size and also their general health, there are several factors that can influence how much melatonin you should give your dog.

As a very general ballpark guide, oral doses of melatonin are typically as follows:

  • 3mg per dose for dogs weighing less than 25lbs
  • 6mg per dose for dogs weighing more than 25lbs

However, these figures are a guide only, so ask your vet to recommend the ideal dosage for your animal. And if you suspect your pet has had an overdose, contact your vet or the poison control hotline as soon as possible.

Have questions or concerns about your pet?

Chat with a veterinary professional in the Wag! app 24/7.

Get Vet Chat

Written by a Labrador Retriever lover Tim Falk

Veterinary reviewed by:

Published: 05/29/2018, edited: 04/06/2020

Wag! Specialist
Need to upgrade your pet's leash?

Learn more in the Wag! app

Five starsFive starsFive starsFive starsFive stars

43k+ reviews


© 2024 Wag Labs, Inc. All rights reserved.

© 2024 Wag Labs, Inc. All rights reserved.