In Australia, melatonin and trazodone are in completely different regulatory categories. Melatonin for dogs is an over-the-counter supplement you can order today; trazodone is a Schedule 4 prescription-only medicine that your vet prescribes off-label after examining your dog. Melatonin is the sensible first move for mild, predictable stress — restless nights, car trips, the groomer, distant thunder. Trazodone is for genuine storm phobia, New Year's Eve panic, post-surgical confinement and diagnosed anxiety.
Australian owners usually arrive here in late spring, with storm season building and last summer still fresh in memory — or after a vet has mentioned trazodone and they'd prefer to try something gentler first. Both are reasonable. Here's the honest comparison, in kilograms, with local realities included.
What's the difference between melatonin and trazodone for dogs?
Melatonin: a signal, not a sedative
Melatonin is a hormone your dog's pineal gland already produces on a light-dark cycle. Supplementing it reinforces the body's own "it's night now" message. It is sold over the counter, isn't a controlled substance, and is generally described as non-habit-forming. What it will not do is knock a dog out. It lowers arousal and makes settling more likely — it does not override a dog already in full panic.
Trazodone: a prescription medicine that genuinely sedates
Trazodone is a serotonin antagonist and reuptake inhibitor (SARI), originally a human antidepressant. In Australia it is a Schedule 4 (Prescription Only) medicine with no registered veterinary product for dogs, so vets prescribe the human formulation off-label — routine and legal, but it requires a consultation and an existing vet-client-patient relationship. It is described in the Merck Veterinary Manual and by veterinary behaviourists as a common choice for situational anxiety and enforced rest. It produces visible sedation, which is both the point and the reason it is restricted.
The distinction that matters
Melatonin changes the conditions in which a dog can settle. Trazodone reduces a dog's capacity to stay wound up. If you need calmer, melatonin may be enough. If you need a Kelpie to stay still on crate rest for six weeks after a cruciate repair, it will not be.
Melatonin vs trazodone: side-by-side
| Melatonin | Trazodone | |
|---|---|---|
| Australian status | Over the counter supplement | Schedule 4, prescribed off-label |
| How it works | Reinforces the natural sleep-wake signal | Modulates serotonin; produces sedation |
| Onset | ~15–30 minutes (liquid at the fast end) | ~1–2 hours; usually given 90 min ahead |
| Duration | ~8 hours | ~4–8 hours, highly variable |
| Strength | Mild — lowers arousal | Moderate to strong — visible sedation |
| Typical use | Restless nights, car and caravan travel, groomers, mild storm nerves, older dogs waking at 3am | Severe storm and firework phobia, fear at the clinic, post-op confinement, diagnosed anxiety |
| Common side effects | Drowsiness, occasional mild GI upset | Sedation, wobbliness, GI upset, panting, rarely paradoxical agitation |
| Serious risks | Very few; wide safety margin | Serotonin syndrome with other serotonergic drugs; cardiac and hepatic caution |
| Cost | Low — from about $21.99 USD, shipped free worldwide | Tablets are cheap; the consult is the real cost |
| Access | Order today | Needs an appointment — book before storm season, not during it |
When is melatonin the right first step?
- Restless nights. A dog that settles late, gets up repeatedly, or has drifted off a normal rhythm — common in humid summer months when dogs sleep poorly anyway.
- Car and caravan travel. Mild anticipatory stress, given half an hour before you set off — useful for the long interstate runs Australian dogs do more of than most.
- Groomers, nail trims, visitors. Short, foreseeable stressors in a dog that's nervous rather than phobic.
- Mild storm nerves. A dog that pants and paces when thunder rolls in but recovers. A dog that tries to dig through a fly screen needs the vet, not a supplement.
- Older dogs with disrupted sleep. Often the first thing tried, alongside a check for arthritis pain or cognitive change. More in our guide to melatonin for senior dogs.
- Mild separation stress — as support alongside training, never instead of it. See melatonin for dogs with separation anxiety.
Melatonin dosing by weight (metric)
Dosing goes by body weight. The ranges below reflect those cited by VCA Animal Hospitals, PetMD and the Merck Veterinary Manual, shown alongside the equivalent volume of a 3 mg/mL liquid.
| Dog's weight | Typical melatonin dose | Volume at 3 mg/mL | Maximum frequency |
|---|---|---|---|
| Under 4.5 kg (Chihuahua, Mini Foxie) | ≈ 1 mg | ≈ 0.33 mL | Up to 3× daily |
| 4.5–11 kg (Cavoodle, Jack Russell) | ≈ 1.5 mg | ≈ 0.5 mL | Up to 3× daily |
| 12–45 kg (Kelpie, Staffy, Labrador) | ≈ 3 mg | ≈ 1 mL | Up to 3× daily |
| Over 45 kg (Bullmastiff, Great Dane) | 3–6 mg | ≈ 1–2 mL | Up to 3× daily |
Give it about 30 minutes before bed or before the stressor, start at the low end, and allow three or four nights before judging. A fuller breakdown lives in our melatonin dosage for dogs chart.
When does your dog need trazodone instead?
Being honest about where melatonin stops is more useful than overselling it. Call the clinic when:
- Your dog is in genuine panic during storms or fireworks — destroying doors, escaping the yard, shaking uncontrollably, injuring itself. Storm phobia is one of the most common serious behavioural presentations in Australian practice, and it tends to worsen year on year if untreated.
- Your dog is on enforced confinement after orthopaedic surgery and can't be kept still by management alone.
- Clinic visits are so distressing that examination is unsafe for your dog or the team.
- A veterinary behaviourist has diagnosed an anxiety disorder requiring medication.
- Melatonin and other non-prescription support have had a proper trial and haven't helped.
A practical local note: the two peak periods are New Year's Eve and the summer storm season, and both are the busiest times for behaviour appointments. If last summer was bad, book in October, not on Boxing Day. Trazodone must not be combined casually with SSRIs, tramadol or other serotonergic medicines — the risk is serotonin syndrome — which is exactly why it is Schedule 4.
Can dogs have melatonin and trazodone together?
Some vets do use both, and melatonin is not serotonergic in the way tramadol or an SSRI is. But this is a decision for your vet, not a backyard experiment. Both cause drowsiness, so combined sedation can exceed what you expect, and a dog on trazodone is by definition under veterinary management — anything you add should go through the same person. Ask at the consult; it takes thirty seconds.
A melatonin worth starting with
If melatonin is the sensible first step, the formula matters. Human melatonin is a poor fit: commonly 5 or 10 mg per tablet, impossible to split accurately for a Cavoodle, and frequently sweetened with xylitol — acutely toxic to dogs.
Our Melatonin for Dogs – Calming & Sleep Support Drops ($21.99) is a liquid, so you measure 0.33 mL for a 4 kg terrier or 1 mL for a 30 kg Kelpie from the same bottle. It is xylitol-free, made in North America under GMP conditions with a certificate of analysis on every batch, and every active is declared per millilitre rather than buried in a proprietary blend:
| Active ingredient (per 1 mL) | Amount | Commonly associated with |
|---|---|---|
| Melatonin | 3 mg | Sleep-wake cycle signalling |
| L-theanine | 50 mg | Relaxed alertness without sedation |
| Alpha-casozepine | 25 mg | Milk-derived peptide used in calming formulas |
| Chamomile extract (water-soluble) | 25 mg | Traditional calming herb |
| Magnesium (elemental) | 5 mg | Normal nerve and muscle function |
| Vitamin B6 (as P5P) | 0.5 mg | Cofactor in melatonin synthesis |
The multi-ingredient approach is deliberate: melatonin handles the sleep-cycle signal, while L-theanine and alpha-casozepine are the ingredients most commonly associated with daytime calm — which is where plain melatonin alone tends to disappoint owners. Liquid also absorbs faster than a chew that has to break down first, which matters when a storm front arrives earlier than the forecast said. Compare options in our guide to the best melatonin for dogs and the broader dog calming and anxiety complete guide. Free worldwide shipping, so Australian delivery costs nothing extra.
Common mistakes Australian owners make
- Expecting melatonin to behave like trazodone. If you need visible sedation, melatonin will look like a failure. It was never that tool.
- Leaving the appointment until storm season has started. Behaviour consults book out. Sort it in spring.
- Grabbing human melatonin from the cupboard. Check for xylitol before anything else — and note the dose per tablet is usually far too high for a small dog.
- Dosing too late. Melatonin needs 30 minutes; trazodone usually 90. Given once the thunder has started, both underperform badly.
- Combining them without asking. Stacking two sedating agents yourself is how dogs end up wobbly and over-sedated.
- Treating a product as a substitute for management. An interior room, sound masking, a secure yard and desensitisation work done in winter do more for storm phobia than anything given on the night.
When to call your vet
Speak to the clinic before starting anything if your dog is pregnant or nursing, is a puppy, is already on medication (particularly SSRIs, tramadol, sedatives or anticonvulsants), has heart, liver or kidney disease, or is diabetic.
Book promptly if anxiety is escalating rather than situational, if your dog is injuring itself or escaping during storms or fireworks, if new night-time restlessness appears in an older dog (this can signal pain, cognitive dysfunction or an endocrine problem rather than a sleep issue), or if melatonin at a sensible dose has done nothing after two weeks.
Treat as an emergency — call your vet or a 24-hour emergency centre immediately — if a dog on trazodone becomes severely disoriented, tremors, develops a racing heart or collapses, or if your dog has eaten a human product containing xylitol. The Animal Poisons Helpline (1300 869 738) is available to Australian owners.
Frequently asked questions
Can I buy trazodone for my dog in Australia without a prescription?
No. Trazodone is a Schedule 4 prescription-only medicine, and because there is no registered veterinary product for dogs, your vet prescribes the human formulation off-label after examining your dog. That requires a consultation and an existing relationship with the clinic.
Is melatonin available over the counter for dogs in Australia?
Melatonin sold as a dog supplement is available over the counter and widely used. Human melatonin is a different matter — most strengths are prescription-only in Australia, and the dose per tablet is usually far too high for a small dog. A dog-specific liquid avoids both problems.
Will melatonin be enough for storms or New Year's Eve?
It depends on severity. For a dog that pants, paces and hides but recovers afterwards, melatonin given 30 minutes ahead — alongside an interior room, sound masking and a secure yard — is often enough. For a dog that panics, escapes or self-injures, it will not be, and that dog needs a veterinary plan made weeks in advance.
How much melatonin for a 10 kg dog?
A 10 kg dog sits in the 4.5–11 kg band, which corresponds to roughly 1.5 mg — about 0.5 mL of a 3 mg/mL liquid — up to three times daily, given around 30 minutes beforehand. Start at the low end and confirm with your vet, particularly if your dog is on other medication.
If your dog's stress sits in the mild-to-moderate range — restless nights, road trips, the groomer, distant thunder — a properly built canine formula is the sensible place to start. Pure Majesty Pets Melatonin for Dogs – Calming & Sleep Support Drops is xylitol-free, declared per millilitre, made in North America with a COA on every batch, measurable to the drop for a 3 kg Chihuahua or a 50 kg Bullmastiff, and $21.99 with free worldwide shipping to Australia. If it isn't enough, you'll walk into the consult with far better information.
This article is for educational purposes only and is not a substitute for professional veterinary advice. Supplements are not intended to diagnose, treat, cure, or prevent any disease and have not been evaluated by the FDA or Health Canada. Always consult your veterinarian before adding melatonin or any supplement to your dog's routine, especially if your dog is pregnant, on medication, or has a health condition.