Trazodone for Dogs: Uses, Side Effects and Safety

By Dr. Rida Batool, DVM. Last updated: October 20, 2026

Vets prescribe trazodone to calm anxious dogs during storms, vet visits, grooming and crate rest after surgery. It is a human antidepressant used off-label in dogs. Most dogs tolerate it well, with sleepiness and stomach upset the usual complaints. Your vet sets the dose, so never guess one.

How trazodone works in dogs

Trazodone raises serotonin activity in the brain, which helps settle fear and restlessness. Many antidepressants work the same way. In dogs, vets mostly use it to take the edge off anxiety, not to knock a dog out.

No veterinary version of trazodone for dogs has been approved, so vets prescribe it extra-label. That is legal and common. It also makes your vet’s directions more important than anything printed on a human label.

When vets prescribe it

• Separation anxiety (see our guide to puppy behavior problems)
• Fear of thunderstorms and fireworks
• Nervous vet or groomer visits, car rides and travel
• Calm crate rest after surgery, such as orthopedic repairs

Some dogs take it only on stressful days. Others take it daily for a behavior problem. Daily use needs patience, since improvement can take a few weeks.

How it is given

For one-off stress, it usually starts working in one to two hours. Vets often ask owners to give it about 90 minutes before the trigger. Daily dosing builds slowly, so expect weeks, not hours.

Ask your vet whether to give it with food, especially if it upsets your dog’s stomach.

How long it lasts depends on the source. PetMD puts it at roughly eight to 12 hours, while other vet sources describe several hours. Ask your vet what to expect for your dog.

Side effects

Drowsiness and a slightly drunken walk are the most common effects. Keep your dog off sofas and stairs until it wears off. For loose stools, our notes on dog upset stomach help.

Rarely, a dog that already leans aggressive becomes more reactive instead of calmer. Tell your vet if you notice that.

Serotonin syndrome: go to an emergency clinic

Rare but serious. It can happen when trazodone meets other medicines or supplements that raise serotonin, especially in large amounts. Watch for:

• Vomiting or diarrhea
• Seizures
• Dilated pupils or vision loss
• Whining or crying
• Heavy drooling
• Trouble breathing
• Weakness, poor coordination or disorientation

Several of these after a dose means an emergency clinic, not a wait-and-see night.

Dogs that need extra caution

• Heart, liver or kidney disease
• Angle-closure glaucoma
• History of aggression
• Working and assistance dogs, since drowsiness lowers awareness

Give your vet your dog’s full medicine list, including vitamins and supplements. Vets often pair trazodone with gabapentin after surgery, and that combination is considered safe when a vet directs it. Mixing it with other serotonin-raising medicines, which include SSRIs, raises the risk of serotonin syndrome. Never add one yourself.

Missed dose or overdose

Missed a dose? Vets often say to give it when remembered unless the next dose is close, and never to double up. Confirm with yours.

Overdose can cause heavy sedation, lethargy, poor coordination and vomiting. Call your vet or the nearest emergency clinic at once, and take the packaging with you.

Why this page has no dose chart

The right trazodone dose for dogs depends on body weight, the reason for treatment, liver and kidney health, and every other medicine your dog takes. No chart can weigh all of that. Follow the label your vet or pharmacist gives you, and ask before changing anything.

Common mistakes to avoid

Several errors are easy to avoid with trazodone.

• Late dosing. Vets often ask owners to give it about 90 minutes before the trigger, so a dose given once the storm starts may come too late.
• Medicine without training. Trazodone supports behavior work. It does not replace training, routine or a behavior plan.
• Unreported supplements. Your vet needs the full list, since some medicines and supplements raise serotonin and add to the risk.
• Human-label dosing. Dose depends on your dog, so follow your vet’s label and never a human tablet’s.
• Worsening unsteadiness. A wobbly walk is a known effect. A dog that cannot stand or wake properly needs a vet.

Questions owners ask

How fast does trazodone work in dogs?

Within one to two hours for one-off stress. Daily use often takes a few weeks to show a change.

What if my dog seems too sleepy?

Mild drowsiness is common. If your dog cannot stand steadily, will not wake properly or keeps vomiting, call your vet or an emergency clinic.

Where do owners get trazodone for a dog?

By prescription from a vet who has examined the dog. Your vet may suggest a compounding pharmacy if a liquid or a different strength is needed.

Is trazodone a long-term fix for anxiety?

It helps, yet medicine alone rarely solves a behavior problem. Pair it with training, routine and a certified trainer if your vet advises. Our overview of anxiety medicines for dogs compares other options.

Sources

• PetMD: trazodone for dogs
• American Kennel Club: trazodone for dogs

General information only, not veterinary advice. Contact your own vet about any health concern with your pet.