Welcome to our complete guide to melatonin for dogs.
The health benefits of melatonin are of growing interest for many dog owners at the moment.
In this article we examine what melatonin does. This includes what it can treat, melatonin dosage for dogs, and if it is right for your Labrador.
Why give dogs melatonin?
If you look up melatonin online, the results are likely to include many amazing benefits. You might think you’ve found a perfect, omnipotent cure-all!
There are sources which recommend melatonin for lots of things. These include:
- alleviating anxiety
- noise phobias
- hair loss
- skin problems
- canine Cushing’s disease
- and stress-induced behaviors such as excessive grooming.
But can melatonin really deliver on all these promises?
What is melatonin?
Melatonin isn’t a drug made by scientists. In fact, it’s a hormone all animals (including us!) make in their pineal gland. That’s a tiny organ in the centre of the brain.
Production of melatonin is inhibited by daylight, so it only happens at night. This has earned it the catchy name “the hormone of darkness”.
Melatonin production is linked to the cycle of night and day. As such, melatonin plays a key role in regulating our internal clocks. It tells diurnal animals to rest at night, and nocturnal animals to wake up.
Because the number of daylight hours changes with the seasons, melatonin levels change too. This prompts animals to make seasonal adaptations.
For many animals, these seasonal changes in melatonin affect the reproductive system. So they breed at the optimal time.
Melatonin is also known to interact with thyroid function and immune function. And did I mention it’s an antioxidant? It really is an amazing hormone!
Can You Give Dogs Melatonin?
Therapeutic use of melatonin first gained traction in the 1990’s. But the first uses weren’t designed for pets.
The link between melatonin and sleep was known. So clinicians started using it to alleviate insomnia and jet lag in people.
It appeared to have a calming effect. Researchers became interested in how melatonin might be used to treat animals in captivity as well.
Melatonin for Dogs
Today, there are many competing melatonin supplements designed just for dogs.
But what exactly are they for?
What does melatonin for dogs do?
Melatonin potentially has lots of clinical uses. We’ll look at some promising new applications on the horizon later.
So far, the main at-home use of melatonin for dogs is to treat fears, anxiety and stress.
Using melatonin in this way was pioneered by Dr Linda Aronson at Tufts University, Massachusetts.
In 1999 she wrote a review of her trials for the Journal of the American Veterinary Medical Association. To this day it is still the most cited evidence for using melatonin to treat dog anxiety and phobias.
Dr Aronson reported that melatonin supplements partially or completely eased the signs of distress in 80% of the dogs she treated.
Melatonin for dogs’ anxiety
For example, your Lab might benefit from taking melatonin if they panic in thunderstorms or fireworks.
Dr Aronson recommended melatonin for any fear. But she observed that it is particularly effective against noise phobias.
She also used melatonin to successfully treat separation anxiety. As well as anxiety or stress caused by strange surroundings or situations, for example flying.
If you’re worried about dog anxiety, take a look at some of our articles here:
How to give melatonin to dogs
Dog melatonin comes as pills, chewable tablets and drops.
They can be plain, or flavored with something like pork.
How does melatonin for dogs’ anxiety work?
Melatonin taken orally is quickly absorbed into the bloodstream.
But after that, no one quite knows how it works!
Dr Aronson, vets, and dog owners across the country have replicated her observations thousands of times over. But surprisingly, no further clinical trials have been carried out.
No one has tried to find the mechanism by which melatonin works to regulate stress, anxiety or fear.
Can I buy melatonin for my dog over the counter?
That depends where you’re reading this.
Melatonin for dogs is available over the counter in the United States and Canada.
In Europe and Australia melatonin is more strictly regulated. It is mostly only available by prescription.
Can I give my dog melatonin?
It is important not to give your dog additional melatonin without consulting their vet first.
Your vet will help you balance the potential benefits of supplemental melatonin against the possible side effects.
They will also be able to tell you if anything in your Labrador’s medical history means they shouldn’t take extra melatonin.
When can you give a dog melatonin?
The simple answer is when your vet says so!
If you think your Labrador could benefit from taking melatonin, the first stop HAS to be your vet.
Melatonin is generally considered safe to give to dogs. However your vet is best placed to balance the case for your individual pet.
They will take a full medical history for your Labrador, and if it’s safe, help you plan a melatonin regimen to meet their needs.
Is melatonin safe for dogs?
Part of melatonin’s appeal is that side effects are rare.
Unlike sedatives and tranquilizers sometimes used to treat stress or anxiety, melatonin doesn’t make dogs drowsy. Dr Aronson even reported using melatonin to calm working search and rescue dogs before flying!
But, only ever give your Lab a melatonin supplement specifically designed for dogs and recommended by your vet. Some melatonin products for humans include ingredients which are poisonous to dogs. For example the sweetener xylitol.
Plus, melatonin for dogs is classed as a supplement rather than a medicine in the US and Canada. This means that the Food and Drug Administration (FDA) regulate it more loosely.
This inevitably means that when you go shopping there are good and poor quality products. Your vet can help you find the former, and avoid the latter.
Are there any dogs that can’t take melatonin?
In 1999 Paul Ashley and colleagues at University College London conducted an experiment. They monitored the levels of sex hormones in the blood of dogs taking daily oral melatonin over 28 days.
Both male and female dogs experienced a decrease in these hormones.
So, melatonin might not be suitable for dogs used for breeding. Nor is it suitable for pregnant dogs or puppies.
Another study in 2018 studied the effect of giving melatonin to both neutered and intact dogs. It found that dogs given melatonin produced more serotonin and less cortisol. These findings suggest that melatonin might be a good treatment for dogs who have had surgery.
Melatonin might also be unsuitable for diabetic dogs, or dogs with an autoimmune disease.
Your vet is best placed to advise whether melatonin is safe for your particular Labrador.
How much melatonin can I give my dog?
One usually gives melatonin as and when needed, rather than continuously. This is the case when treating anxiety, fear and stress.
If you know an event is coming up which is likely to upset your dog, you’ll be able to start giving melatonin a little in advance.
But, if this isn’t possible, Dr Aronson still recommends giving it at the first signs of stress.
Your dog will absorb melatonin and retain it in his bloodstream for some time. Typically, you need to repeat dosages every eight hours, or until the trigger for the anxiety has ended. Check with your vet if you’re not sure.
Melatonin dosage for dogs
I can’t stress enough the importance of getting your vet’s advice.
Melatonin dosage for dogs differs based on each dog’s weight among other factors. Your vet is best to advise you on a specific dose for your dog.
But to give you an idea, Dr Aronson recommends the following dog melatonin doses:
- For dogs under 10 pounds: 1 milligram.
- Dogs between 10-25 pounds: 1.5 milligrams.
- Finally, dogs weighing 25-100 pounds: 3 milligrams.
- 3 milligrams is often enough for dogs over 100 pounds. But you can give them up to 6 milligrams.
Though melatonin is relatively safe, it is always better to check with your vet first.
Dog melatonin side effects
Unwanted side effects of melatonin are rare, but not unheard of.
Look out for the following signs that extra melatonin is not sitting well with your Lab:
- changes in fertility
- gastric upset and stomach cramps
- increased heart rate
- confusion or disorientation
If you notice any of these, stop using melatonin immediately, and consult your vet again.
Dog melatonin overdose
Your dog will absorb melatonin quickly. However, he will excrete it in urine much more slowly.
So it is possible to overdose if your dog has too much at once.
Keep melatonin products well out of reach of your Lab. Some manufacturers flavor these treats so that they appeal to your pooch. It’s best if you keep them hidden away.
Symptoms of overdose include dizziness, seizures and vomiting.
If your dog starts to show any symptoms of overdose, take them to the vet immediately.
Melatonin for dog hair loss
Labradors have a slight genetic predisposition to seasonal alopecia in spring and summer. These are bald patches on their flanks which go beyond normal molting.
Longer days and shorter nights cause a natural dip in melatonin levels. There is a link between this dip and seasonal hair loss. But, the connection is something of a mystery.
Delivered orally, you can give your dog melatonin easily. Alternatively, implants under the skin are successful in treating 50-75% of seasonal alopecia cases. Veterinary textbooks now routinely recommend these.
To use melatonin to treat hair loss in your Labrador, consult your vet first.
Melatonin for dogs – what does the future hold?
Melatonin is already bringing relief to many pets, but some really exciting uses for it are still at the clinical research stage:
Dog melatonin for healing
In 2007, Antonio Cutando and his team at the University of Grenada applied melatonin to the gums of Beagles following tooth extraction. They found it reduced oxidative stress caused by the extraction.
Melatonin is also being testing in dentistry. Applying powdered melatonin at the site of dental implants in beagles accelerated bone formation in early stages of healing. We know this as a result of a 2009 study by Dr Fernando Muñoz and his team.
And in 2015, Pablo Sande and his team at the University of Buenos Aires found that melatonin reduced inflammation in dogs recovering from cataract surgery. Their report found that after surgery, melatonin seemed more effective than NSAIDs (a kind of painkiller).
As you can see, a variety of dog care experts are studying melatonin. In 2014, Juliana Ramos Lopes produced a study. They looked at the effect of giving melatonin to female dogs with tumors. They found that melatonin can be useful in making cancer cells in breast tissue weaker. Interestingly, Ramos Lopes stated that ’canine mammary tumors are an excellent model for the study of breast cancer’ in humans.
Melatonin for dogs – summary
Melatonin is a fascinating hormone.
We know it has lots of roles inside us and our dogs to help us function properly. We just don’t know how it manages it all yet.
Melatonin for dogs already has some established uses treating fear, anxiety, stress, and hair loss. Perhaps one day it could also be a routine part of some surgeries to reduce inflammation and accelerate healing.
Used correctly it is incredibly safe. It can have fewer side effects than it’s pharmaceutical alternatives.
Do your dogs take melatonin?
Has your vet recommended melatonin for your Labrador? What symptoms is it being used to treat?
Please share your experiences in the comments section below!
We have revised this article for 2019. It has also been fact checked by our team medic, Dr S. Austwick MBBS.
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American Kennel Club
Aronson, L., “Animal behavior case of the month. A dog was evaluated because of extreme fear”. Journal of the American Veterinary Association, 1999.
Ashley, P. et al. 1999 ”Effect of oral melatonin administration on sex hormone, prolactin, and thyroid hormone concentrations in adult dogs”. Journal of the American Veterinary Medical Association
Cutando, A. et al. 2007 ”Local application of melatonin into alveolar sockets of beagle dogs reduces tooth removal-induced oxidative stress.” .Journal of Periodontology
Dunlap, K. et al. 2007 “Seasonal and diurnal melatonin production in exercising sled dogs” Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology
Mecklenburg, L. et al. 2009 “Hair Loss Disorders in Domestic Animals” . Wiley Blackwell
Muñoz, F. et al. 2009 “Topical Application of Melatonin and Growth Hormone Accelerates Bone Healing around Dental Implants in Dogs” . Clinical Implant Dentistry and Related Research
Husääf, J. et al. 1980 “Melatonin administration to dogs” . Journal of Neural Transmission
Sande, P. et al, 2015 “Preliminary findings on the effect of melatonin on the clinical outcome of cataract surgery in dogs” . Veterinary Opthalmology
Ramos Lopes. et al, 2014 ’Evaluation of melatonin treatment in primary culture of canine mammary tumors’. Spandidos Publications
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