Trazodone for Dogs and Cats

Medically Reviewed by Joshua Conrad, PharmD on September 03, 2024
Written by Kathleen Claussen, DVM
5 min read

Trazodone (brand names: Desyrel, Oleptro) is a medicine used in both dogs and cats.  It’s also sometimes used in horses.

Trazodone works as a serotonin antagonist/reuptake inhibitor, or SARI. It helps reduce anxiety and calm small animals and horses. It increases the level of serotonin in the central nervous system, which includes the brain and spinal cord. Serotonin is a natural brain chemical that helps carry messages between the brain and body.

In dogs, trazodone is used as an anxiolytic, meaning it lessens anxiety. It can be given before stressful events, such as going to the vet or being groomed, being near fireworks, riding in a vehicle, or experiencing storms. Trazodone may be used by itself or with other medicines to get best results.

In cats, trazodone is usually used to lessen their fear and stress associated with travel, vet visits, and other stressful situations.

Trazodone is prescribed extra-label or off-label in veterinary medicine. That means there’s evidence it’s safe and effective, but it’s not FDA-approved for use in animals. Trazodone is generally well-tolerated in animals.

Trazodone is available as a prescription medication from your veterinarian or from a pharmacy with a veterinary prescription.  It comes in different doses as tablets.  Contact your veterinary compounding pharmacy for other dosing options.

Trazodone is usually given by mouth as a tablet. It can also be compounded into other forms, such as a liquid, to make it easier for your pet to take. For occasional use, it’s best to give trazodone 1-2 hours before stressful events.  For long-term use, it can be given every day. It may take up to 2 weeks to see its full effect, especially if it’s not used with other medicines.

Trazodone may be given with or without food.  If your pet vomits after taking it on an empty stomach, try giving it to them with a small amount of food or a treat.

Compounding pharmacies can make smaller trazodone tablets and pet-safe liquid versions for smaller dogs, dogs who won’t take tablets, and cats.

Always follow your veterinarian’s directions for giving medicines to your pet. Tell them about any medicines, vitamins, supplements, or herbal therapies that you give your pet. Talk to your vet before stopping any pet medicines.  

Trazodone that’s given long-term shouldn’t be stopped abruptly. Long-term trazodone should be decreased slowly over time according to your vet’s recommendation.

The pros of trazodone for dogs and cats include the following.

  • It’s quickly absorbed by your pet’s body, and they should feel calmer in 1-2 hours.
  • It can help calm your pet’s anxiety in many situations. 
  • It can be used as needed or long term.
  • It can be used with other medicines to treat issues that don’t get better with just one medication.
  • When your pet takes trazodone before general anesthesia, your vet may be able to lower their doses of any other medicines.

You and your veterinarian should monitor your pet for improvement and side effects. There are usually no routine blood tests needed.

Yes. Its warnings include: 

  • Don’t use trazodone if your pet is allergic to it or they’re pregnant. 
  • Don’t use trazodone if your pet has severe heart disease, liver issues, or kidney issues. 
  •  Use trazodone with caution if your pet has an eye condition called angle-closure glaucoma. That’s because trazodone may dilate their pupils and cause problems.  
  • Use trazodone with caution if your pet is a service or working animal, as it may interfere with their ability to perform their duties.

Side effects include:

  • Vomiting
  • Diarrhea
  • Tiredness or sleepiness
  • Lack of coordination
  • Irregular heartbeat or increased heart rate
  • Dilated pupils
  • Increased anxiety
  • Aggression

Cats may have vomiting, diarrhea, tiredness, sleepiness, or drooling. Their side effects usually go away in 8 to 12 hours. Some side effects may need to be treated if they last longer than 12 to 24 hours or get worse during that time. Your cat’s side effects may last longer if they have heart, kidney, or liver problems.

Dogs may get a rare but serious condition called serotonin syndrome when they take trazodone with other medicines that also affect serotonin.  If your dog has serotonin syndrome, they need emergency care. They may have serotonin syndrome if they have more than one of these symptoms:

  • Vomiting or diarrhea
  • Seizures
  • Elevated body temperature (above 102.5 F)
  • Dilated pupils
  • Difficulty breathing
  • Depression (they’re withdrawn and/or inactive)
  • Skin sensitivity
  • Excessive drooling
  • Disorientation
  • Paralysis

If you think your pet is having a serious side effect or they’re overdosed, call your veterinary clinic immediately. If it’s outside regular office hours, you may contact a local emergency veterinary hospital or an animal poison control center. You may have higher fees for emergency care.

You can reach the ASPCA Animal Poison Control Center at 888-426-4435 or the Pet Poison Helpline at 855-764-7661.

Using multiple medicines for your pet can sometimes change how those medicines work or increase your pet’s risk for serious side effects. Always tell your veterinarian about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements that your pet takes.

Before starting your pet on trazodone, tell your vet if your pet takes the following: 

Anticoagulants and antiplatelet agents. These medicines help prevent blood clots in your pet. When taken with trazodone, they may increase the risk of bleeding inside your pet’s stomach or intestines. If they’re taken together, you should monitor your pet for signs of bleeding. Ask your vet what to look for.

Medicines that can increase the risk for serotonin syndrome.  Using trazodone with other medicines that affect serotonin can increase yourpet’s risk of serotonin syndrome. These medicines include the following. 

  • Buspirone
  • Methylene blue
  • Tramadol
  • Medicines called monoamine oxidase inhibitors, or MAOIs
  • Medicines called selective serotonin reuptake inhibitors, or SSRIs
  • Medicines called tricyclic antidepressants, or TCAs
  • Other serotonergic medicines

Even though serotonin syndrome is rare, the use of trazodone with any other serotonergic medicines may result in your pet needing emergency treatment.

Medicines that may increase your pet’s blood level of trazodone. These include medicines known as azole antifungals, macrolide antibiotics, and phenothiazines. When taking trazodone with these types of medicines, the dose of trazodone may need to be decreased.

Medicines that may decrease your pet’s blood level of trazodone. These medicines include phenobarbital and rifampin.  When taking trazodone with these types of medicines, the dose of trazodone may need to be increased.

This isn’t a complete list of medicines that can interact with trazodone. Always check with your veterinarian.

For safety, keep trazodone out of the reach of children. Also, wash your hands after giving trazodone to your pet. Don’t handle trazodone if you’re allergic to it.

Trazodone tablets should be protected from light and stored at room temperature. Compounded forms of trazodone should be stored according to the compounding pharmacy’s recommendations.