Prozac for Dogs: How and When to Use It

Medically reviewed by James Edward, PharmD

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What Is Prozac?

Prozac is an antidepressant in a class known as serotonin reuptake inhibitors or SSRIs. It allows serotonin to stay active in the brain longer and is commonly used to treat anxiety and depression. Studies show that effective Prozac use not only reduces unwanted behaviors in dogs but can actually improve their mental health experience.

Is Prozac Safe?

Prozac is prescribed by many veterinarians for pets, including dogs. Although some circumstances that Prozac is prescribed for are off-label (not FDA-approved for specific uses), many doctors and veterinarians routinely find a benefit in prescribing drugs for off-label uses for both human and canine patients. Prozac has been tested in dogs, prescribed for dogs for over 30 years, and is considered safe. Be sure to inform your veterinarian of any other medications that your dog is taking.

What About Pregnancy/Nursing?

Prozac is not recommended for use during nursing or pregnancy.

What is Prozac Used For?

Prozac is used to prolong the presence of serotonin in the brain, which can help to alleviate anxiety, depression, compulsive behaviors, and fear. Many dogs struggle with anxiety throughout portions of their life, depending on their environment. Breeds who are high-energy and do not receive enough regular exercise and dogs who are kept indoors most of the time are likely candidates to develop anxiety. Anxiety comes in different forms, including separation anxiety, thunderstorm anxiety, or anxiety overlapping with various phobias. Prozac can reduce the level of anxiety experienced by increasing the use of serotonin by the brain.

General Anxiety

Anxiety in dogs is usually caused by specific triggers rather than a generalized feeling. These can include loud sounds, strange environments, separation from their owner or “pack,” car rides, visiting a place they have previously had unpleasant experiences, or going to the veterinarian’s office or groomer’s. Most dogs will display some level of anxiety when experiencing these, but for dogs with high anxiety the symptoms may be amplified to the point where they become difficult to handle. These behaviors, such as destructiveness, incessant barking, and ignoring commands, can make your dog seem stubborn and problematic.

There are cases of age-related anxiety as well that are related to the loss of cognitive function. As dogs age, like humans, they begin to lose memory, awareness, and perceptive ability. They are discomforted by new situations that challenge their decreasing ability to learn and adapt, and this can lead to anxiety and problem behaviors. Prozac can increase the feelings of calm and relaxation in aging dogs, relieving this type of anxiety.

Separation Anxiety

When their humans leave home, it seems like the many dogs with separation anxiety can completely transform their personality. Destroying furniture, leaving trails of poop, urine, and stuffing everywhere, chewing up baseboards - even drywall sometimes doesn’t stand a chance. For indoor dogs in particular, this type of anxiety is common. Even being in a separate room with a closed door may trigger a dog’s separation anxiety. Since most owners have to be away from home to work, Prozac may be a good choice to help their dogs stay calm through that 9-to-5.

Thunderstorm Anxiety

Not just thunderstorms, but fireworks, gunfire, and any other sudden, loud noises can trigger intense anxious reactions. If you aren’t always around to give your dog reassurance, or if they still exhibit anxious behaviors with you around, Prozac may be a good option. Its calming effects can help dogs endure triggers with milder reactions.

Peeing Behaviors

Dogs who urine-mark the house may do so for one or more of several reasons: separation triggers, sexual drive, lack of exercise, bladder control issues, general age-related anxiety, etc. They may also be using it as a communication tool towards a new dog in the home. Prozac can calm and relax your dog through these experiences, reducing the likelihood of urination.


Anxiety can cause or amplify aggressive behaviors in dogs, including age-related anxiety. When a dog uses body language (barking, snarling, growling, snapping, or engaging in harmful behavior) to threaten another individual, they are implementing aggressive behavior. Prozac can help lower their anxiety which leads to a lower risk of your dog resorting to aggressive behaviors.

Phobias (Fear Disorders)

Phobias can be caused by previous unpleasant experiences, and they leave dogs with irrational, intense fears. Common human phobias are fears of heights, needles, or spiders. In dogs, you may be able to pinpoint the triggers, such as loud noises, even if you don’t know what caused them to develop the phobia.

They can be related to needles and injections, car rides, severe separation anxiety, and fear of strangers - particularly individuals with similar physical traits as someone who may have abused them in the past. Prozac helps dogs to feel calmer through these triggers, decreasing the level of fear they may experience.

Compulsive Disorders

Compulsive disorders in dogs can present in ways such as excessive tail-chasing. These disorders are more difficult to diagnose in dogs than in humans. Dogs with CCD (Canine Compulsive Disorder) will engage in normal behaviors for dogs, but on a level that is considered excessive and harmful.

It can be difficult to tell whether your dog’s excited behavior is normal or genuine CCD. A veterinarian can help you determine if your dog is exhibiting concerning or excessive traits that may be indicative of CCD. Similarly to OCD in humans, experts think that CCD arises from mismanagement of serotonin in the canine brain. Prozac and other SSRIs were developed to regulate that imbalance.

What Are The Side Effects of Prozac?

Like most drugs, Prozac may not be right for everyone (or every dog). If you notice any of these side effects when starting your dog on Prozac, especially during the first week, contact your veterinarian:

  • Loss of Appetite - this is one of the more common side effects for dogs on Prozac. If your dog’s lack of interest in dinner coincides with starting Prozac, it may be throwing off their eating habits.
  • Worsening Behaviors - if a specific serotonin imbalance is not the cause for your pup’s anxiety or aggression, Prozac may exaggerate the behaviors. Not all difficult canine behaviors are caused by this imbalance.
  • Upset Stomach - Prozac may cause nausea and vomiting, just like many other drugs do in both humans and dogs. Try giving it with a meal and see if you notice improvement.

Prozac Dosage for Dogs

Your veterinarian will provide the correct dose of Prozac for your dog, as it is a prescription medication. Typically, the daily dosage for dogs would be 1 mg/kg daily, according to the Merck Veterinary Manual. It’s best to give your dog the medication at the same time each day, and if it causes an upset stomach, then the ideal time would be with a meal.

You won’t want to wait until your dog is triggered and starts displaying anxious behaviors to give them Prozac, as it doesn’t have an instant effect. It takes 6-8 weeks to build up in their system, although you may begin to notice some of the effects just a few days after starting them on it.

When stopping Prozac, you will need to wean your dog off of it over time. With an abrupt discontinuation, they could have trouble regulating to the change, which may lead to even more intense behavioral struggles than the ones that caused you to give them Prozac in the first place. Be sure to consult your veterinarian on how to taper the dosage for your dog if stopping Prozac.

Prozac Dosing Table

Dog’s Weight (kg) Usual Dosage of Prozac per day (mg)
10 10
20 20
30 30
40 40
50 50
60 60
70 70
80 80
90 90
100 100

Prozac Cost

Your veterinarian or local pharmacist should be able to give you an accurate estimate of how much Prozac will cost for your dog, but you may be able to purchase it for as little as $4 per month.

Prozac Alternatives or Adjuncts

Lifestyle changes are typically preferable alternatives to Prozac, but not always feasible depending on your schedule and your dog’s requirements. Even with a lifestyle shift, Prozac may be helpful as a supplemental anti-anxiety treatment.


Consider taking an in-person or online training class with your dog to learn techniques for helping them manage their anxiety, and how to avoid unintentionally exacerbating their unwanted behavior. Your veterinarian may also have helpful tips and/or resources that you can use to work with your pup.


Anxiety, worry, and stress in both humans and dogs can be amplified by a lack of exercise. High-energy breeds in particular can suffer from more intense anxiety when they don’t have an appropriate outlet for that energy. Herding dogs and dogs bred for running may need as much as half an hour or more of exercise on a daily basis to exhaust their pent-up energy, so it can be difficult to meet their needs. Without the ability to channel that focus into positive outlets, they could display unwanted behaviors such as aggression, phobias, and loud or destructive tendencies.

Correcting Underlying Causes

Underlying issues, such as age-related cognitive decline, can cause some aggression and anxieties. Drugs like selegiline are developed to help correct that decline and can reduce the anxiety or aggression it causes. If you have noticed a correlation between your dog’s aging and their anxious or aggressive behaviors, bring it up with your veterinarian, as they will have to be the ones to make the diagnoses.

Other Medications

Prozac is not the only SSRI that is used in dogs. Others prescribed are Celexa or citalopram, Paxil or paroxetine, and Zoloft or sertraline. They have many of the same benefits and side effects as Prozac, but certain dogs may respond better to one than another or be less likely to experience negative effects.


Cannabidiol, or CBD, has been found by veterinarians and many owners to help with anxiety, aggression, and other issues Prozac also treats. Unlike Prozac, it has not been reported to have as many or as severe side effects at the usual dosing - especially when using a high-quality, third-party lab-verified broad spectrum CBD oil. Broad spectrum CBD oil doesn't contain any THC, hemp's psychoactive cannabinoid.

Multiple studies have shown that broad-spectrum hemp extracts can help relieve anxiety and similar symptoms in dogs effectively without severe side effects.

If discussing options with your veterinarian, CBD is worth mentioning. If Prozac or other prescription medications are too expensive, or if they are causing intolerable side effects, CBD may be an alternative that works for your dog.


Prozac is an SSRI that has been prescribed for off-label use in dogs for decades and shown to be helpful in long-term management of certain types of anxiety. Its use must be authorized by a veterinarian as it is a prescription medication, and any concerning side effects should be brought to their attention as well. Owners should be well-informed before starting their dog on Prozac or taking them off of Prozac as it builds up in the system over time, and weaning is necessary. If owners have any concerns about the use or cost of Prozac, alternatives such as CBD may offer comparable relief with fewer side effects.


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Ever since she was a puppy, she’d spend her days running and playing. I’d take her on walks, to the beach, and dog parks.

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