Amitriptyline for Dogs: This Medication Can Help Treat Anxiety and Pain

Amitriptyline is a tricyclic antidepressant used in dogs for separation anxiety and generalized anxiety. It is also used for itchiness and nerve pain in some dogs.

Amitriptyline is not FDA approved for use in dogs. But it can still be prescribed “extra-label” or “off-label.”

Amitriptyline for dogs at a glance

What is amitriptyline, and how does it work?

Amitriptyline is a tricyclic antidepressant. It has been used for over 50 years in human medicine for nerve pain and mood disorders and over 20 years in dogs for the same reasons.

Amitriptyline works in several ways, including increasing levels of “happy” chemicals, such as dopamine and serotonin, in the brain. Increased levels of “feel-good” chemicals can reduce your dog’s pain perception and stabilize mood. 

Amitriptyline also works by blocking alpha-1 adrenergic receptors, which reduces fear. Interestingly, amitriptyline also blocks histamine release, effectively functioning as an antihistamine. This can also make it helpful for itchy dogs.

What is amitriptyline used for in dogs?

Amitriptyline is used to manage generalized anxiety and separation anxiety in dogs. It has also been used to control itching, acral lick dermatitis, and nerve pain in dogs.

Amitriptyline is most effective in treating anxiety in dogs when it is used in conjunction with a long-term behavioral modification plan. 

What is the typical dose of amitriptyline, and how is it given to dogs?

Amitriptyline comes in tablets ranging from 10 mg to 150 mg. The tablets can be split in half or quarters if necessary, based on what your dog needs. 

The standard dosage for dogs is 1 mg/kilogram to 2 mg/kilogram of body weight every 12 to 24 hours. However, amitriptyline works differently in every dog. Your dog’s specific dosage will vary based on several factors, including:

• The issue being treated with amitriptyline

• The weight and overall health of your dog

• Any other medications your dog already takes

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Your veterinarian will determine the appropriate dose for your dog. Follow your veterinarian’s dosing instructions exactly, and be aware that they may be different from what is written on the medication’s label.

Typically, a veterinarian will start a dog out at a lower dose of amitriptyline to minimize potential side effects. If there is no improvement or if your dog experiences side effects, your vet will adjust the dosage of amitriptyline. This adjustment process may take several weeks. Patience, trusting the process, and consistent communication with your veterinarian are key to getting the best results. 

It is best to give amitriptyline with food to increase absorption and reduce potential stomach upset. Amitriptyline can also be compounded into an oral liquid or chew. 

After handling the medication, wash your hands. 

What are the common side effects of amitriptyline in dogs?

The most common side effects of amitriptyline for dogs include:

• Sedation

• Dry mouth

• Holding their urine

• Constipation

A few dogs may exhibit hyperactivity instead of sedation when prescribed amitriptyline. 

If your dog is taking amitriptyline long term, your veterinarian will likely want to see your dog every 6 to 12 months. They will conduct a physical examination and lab work to ensure that the medication is effective and not causing any problems with your dog’s body.

Amitriptyline’s effects should wear off in a couple of days. However, amitriptyline may last longer in the bloodstream in dogs that have been diagnosed with liver or kidney disease.

Amitriptyline alters the level of your dog’s brain chemicals and should not be discontinued abruptly. If you need to stop giving your dog amitriptyline, first consult with your veterinarian. They can give you instructions on how to safely wean your dog off of the medication. 

What are the most serious risks of amitriptyline for dogs?

Rare but more serious side effects of amitriptyline for dogs can include:

• Fast or irregular heartbeat 

• Seizures or tremors

• Decreased blood cell count

• Vomiting

• Diarrhea

• Hormonal imbalances

If your dog has been prescribed amitriptyline and you notice any of these side effects, call your veterinarian as soon as possible for advice. 

If you suspect your dog has had an overdose of amitriptyline, call your local veterinarian, emergency clinic, or a pet poison hotline immediately.

Does amitriptyline interact with any other dog medications?

There are hundreds of medications that are known to interact with amitriptyline. If your dog takes any other medications, herbs, vitamins, or supplements, let your veterinarian know before your dog is prescribed amitriptyline. Your veterinarian will then be able to determine if it’s safe for your dog to take amitriptyline.

What should you do if your dog misses a dose of amitriptyline?

When prescribed to dogs, amitriptyline is given every 12 to 24 hours. If you miss a dose of the medication, give the next dose as soon as possible. Then continue your regular medication schedule the next day. Never give two doses of any tricyclic antidepressant, including amitriptyline, at the same time or closer than 12 hours together.

Why trust our experts?

Written by:

Sarah J. Wooten, DVM, CVJ

Dr. Sarah Wooten, DVM, CVJ, is a well-known international influencer in the veterinary and animal healthcare spaces. She has 16 years of experience in private practice and more than 15 years experience in veterinary media work.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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