Trazodone for dogs: uses, side effects and how long it lasts

Trazodone is a prescription medicine that vets use to take the edge off anxiety in dogs. It is most often given for short, predictable stresses such as vet visits, storms, fireworks, travel and the weeks of enforced rest after surgery. It usually starts to work within an hour or two and wears off over the following hours.

It was developed as an antidepressant for people, and vets prescribe it for dogs "off label", which is legal and routine. This site does not give doses for any medicine. The right amount depends on your dog's weight, age, liver, kidneys and other medicines, and only the prescribing vet can set it.

What trazodone is prescribed for

• Vet visits and grooming. Given beforehand so a fearful dog can be handled with less distress.
• Storms, fireworks and travel. Events you can see coming.
• Crate rest. Keeping a dog quiet for weeks after orthopedic or spinal surgery is hard, and trazodone is commonly used to make it bearable.
• Night-time anxiety. Including the evening and overnight restlessness, often called sundowning, seen in some dogs with dementia.
• Longer-term behavior plans. Sometimes given on a regular schedule, usually alongside another behavior medicine and training.

Trazodone calms the dog. It does not treat whatever is causing the distress. In an older dog, new anxiety or restlessness often has a medical cause such as pain, failing senses, heart or breathing trouble, or needing to urinate more often, so a vet will usually look for those before reaching for a calming drug.

Is trazodone a sedative for dogs?

Partly. It works on serotonin, one of the brain's chemical messengers, and the result is a mix of reduced anxiety and drowsiness. Most dogs on it are quieter and sleepier but can still be woken, walk, eat and go outside. It is not an anesthetic.

It is also not pain relief. A dog who cannot settle because something hurts needs the pain treated by a vet. Never reach for human painkillers: ibuprofen, naproxen, acetaminophen (paracetamol) and aspirin can seriously harm or kill dogs.

How long does trazodone take to work in dogs?

For a single dose before an event, an hour or two is the commonly reported range. That is why vets usually ask you to give it well ahead of the car ride or the first firework, not once the dog is already frightened. A dog who is already panicking tends to respond less.

Many vets suggest a trial run at home on an ordinary day, so you know how your dog reacts before it matters. When trazodone is given regularly as part of a behavior plan, the vet may want a few weeks before judging it.

How long does trazodone last for dogs?

The main effect commonly lasts several hours, and some dogs stay a little drowsy for the rest of the day. Most are back to normal by the next day. It varies a lot from dog to dog.

Trazodone is broken down by the liver and cleared through the kidneys. Older dogs, and dogs with liver or kidney disease, clear it more slowly, so the effect can be stronger and last longer. Vets often start cautiously in these dogs for that reason.

Trazodone side effects in dogs

• Sleepiness and low energy
• Wobbliness or weak back legs
• Vomiting, diarrhea or drooling
• A bigger appetite than usual, or occasionally a smaller one
• Panting and wide pupils
• Agitation, the opposite of what was intended

What an over-sedated dog looks like

Hard to wake, unable or unwilling to stand, stumbling into things, uninterested in food or water, or breathing slowly and shallowly. A dog like this needs a call to the vet, not a wait until morning.

Mild wobbliness matters more in an old dog. A sedated dog with arthritis or weak back legs can fall on stairs or slip on a hard floor, so keep them on one level, block the stairs and help them outside on a lead.

What an agitated dog looks like

A small number of dogs go the other way: pacing, panting, whining, trembling and unable to lie down. Do not give more to push through it. Tell the vet, who may change the amount or the medicine.

Trazodone and dog aggression

Vets sometimes include trazodone in a plan for a dog whose aggression comes from fear, for example at the clinic. It is not a treatment for aggression by itself, and a drowsy dog can still bite. In some dogs it lowers inhibition, which can make a bite more likely, not less.

Keep every safety measure in place while a dog is on it, and tell the vet at once if your dog becomes more irritable. When an older dog turns aggressive without warning, pain or illness is a common reason and needs checking first.

Is trazodone safe for dogs?

It is widely prescribed and most dogs tolerate it, but no medicine is free of risk, and the main danger comes from what it is combined with.

Serotonin syndrome

Trazodone raises serotonin activity. Given with other medicines that do the same, serotonin can climb to a dangerous level. The medicines vets watch for include:

• Tramadol, a pain medicine
• Fluoxetine, clomipramine and other antidepressants
• Selegiline, used for canine dementia
• Amitraz, found in some tick collars and dips

Signs include agitation, tremors or twitching, a racing heart, a high temperature, wide pupils, vomiting and diarrhea, and in severe cases seizures. It is an emergency.

This matters most for old dogs. The dog who is pacing at night with cognitive dysfunction may already be on selegiline, and the dog with arthritis may be on tramadol. Selegiline and amitraz are generally not combined with trazodone at all. Vets do sometimes pair trazodone with one of the other serotonin medicines on purpose, with adjusted amounts and close monitoring, but that is their decision to make. Give the vet a full list of everything your dog gets, including supplements and flea and tick products.

Dogs who need extra caution

Vets are careful with trazodone in dogs with liver or kidney disease, heart disease or an irregular heartbeat, glaucoma, or a history of seizures, and in dogs on blood pressure medicines, because trazodone can lower blood pressure.

Can trazodone cause seizures in dogs?

It is uncommon. Seizures have been reported, mostly with overdoses or serotonin syndrome, and vets are cautious about prescribing it to dogs who have had seizures before. Any seizure in an older dog needs a vet the same day, whatever medicine is involved.

Missed dose, double dose and trazodone overdose

If you miss a dose, call the clinic and ask what to do. Do not give two together to catch up.

If your dog has had a double dose, has chewed into the bottle or has eaten a person's tablets, call your vet, an emergency clinic or an animal poison control line right away, even if the dog seems fine. Have the container in your hand so you can read out the strength and how many are missing. Signs of overdose include heavy sedation, stumbling, vomiting, tremors, agitation, a very fast or very slow heart rate, collapse and seizures. Do not try to make your dog vomit unless a vet tells you to.

Never share a human prescription

Trazodone for dogs is the same drug people take, which makes sharing tempting. Do not do it. The strength of your tablets, whether they are an extended-release type and the amount that suits a person are all wrong starting points for a dog, and no one has checked it against your dog's other medicines. Give only what the vet prescribed for this dog.

Call the vet today if

• Your dog is very hard to wake, cannot stand or is breathing slowly
• You see tremors, twitching, a racing heart, heavy panting at rest or a seizure
• Your dog becomes agitated, frantic or aggressive after a dose
• Vomiting or diarrhea is repeated or does not stop
• Your dog collapses or faints
• Your dog got more than was prescribed, or got trazodone that was not prescribed for them
• The anxiety or night-time panting is getting worse despite the medicine

Collapse, seizures and severe agitation are for an emergency clinic now, not a message left for the morning.

Questions to ask the vet

• What are we treating, and has pain or another illness been ruled out?
• How long before the event should I give it, and with or without food?
• Should I do a trial run at home first?
• Is it compatible with everything else my dog takes, including tick products?
• Do my dog's age, liver or kidneys change the plan, and do we need blood tests?
• What should I do if it does not seem to work?

This page is general educational information about trazodone, not veterinary advice, and it deliberately gives no doses. Whether trazodone suits your dog, how much to give and what it can be combined with are decisions for your own veterinarian, who knows your dog's health and other medicines. If you think your dog has had too much or is reacting badly, contact a vet or an animal poison control line immediately.