Fluoxetine for Dogs: Uses & Side Effects

Like humans, dogs can also experience emotional and behavioral challenges that can greatly impact their quality of life. Fortunately, there are many ways you can help them combat these issues, from positive reinforcement training and behavior modification to medications like fluoxetine.

Fluoxetine, most commonly known by its brand name Prozac, is a selective serotonin reuptake inhibitor (SSRI) commonly prescribed to address a wide range of behavioral issues in dogs. These issues include anxiety, aggression, obsessive-compulsive behaviors, and more. 

In this blog post, we will delve deeper into the topic of fluoxetine for dogs, shedding light on its uses, side effects, appropriate dosages, and important safety information. Whether you believe your dog could benefit from fluoxetine or you're simply interested in learning more, follow along.

• What Is Fluoxetine?
• What Is Fluoxetine Used For In Dogs?
• Fluoxetine Side Effects
• Fluoxetine Dosage For Dogs
• Are There Alternatives To Fluoxetine For Dogs?
• Fluoxetine For Dogs: FAQs
• Final Notes

What Is Fluoxetine?

Fluoxetine, also known by the brand names Prozac, Reconcile, and Sarafem, is a selective serotonin reuptake inhibitor (SSRI) primarily used in humans to treat depression, panic attacks, obsessive-compulsive disorder (OCD), bulimia, and premenstrual dysphoric disorder.¹

While fluoxetine’s exact mechanism of action is yet to be fully understood, like other SSRI antidepressants, it inhibits the reuptake of serotonin to prolong and enhance its effect. This in turn helps to improve mood, reduce feelings of anxiety, and alleviate other symptoms associated with conditions like depression and OCD.¹

What Is Fluoxetine Used For In Dogs?

Fluoxetine for dogs is used to manage a range of behavioral problems, including:

• Separation anxiety: Separation anxiety in dogs can manifest as destructive behavior, barking, whining, and other signs of distress when left alone. Fluoxetine can help reduce these behaviors by increasing serotonin levels, which can help your dog feel calmer and more at ease when alone. Anxiety training can also be helpful.²
• Obsessive-compulsive disorder (OCD): Dogs with OCD may exhibit repetitive behaviors like excessive licking or chewing, tail chasing, or pacing. As your dog’s serotonin levels increase, their feelings of anxiety and compulsion will decrease.³
• Aggression: Fluoxetine is sometimes used to manage aggression in dogs. Increased serotonin levels can help reduce aggressive behavior by making the dog feel calmer and less fearful. However, it's important to note that fluoxetine is not a cure for aggression, and behavior modification therapy should be used alongside medication for the best results.⁴
• Fear: Fear-based behaviors, such as fear of loud noises or new situations, can also be managed with fluoxetine. The increased serotonin levels can help the dog feel calmer and less reactive in these situations.⁵
• Depression: While depression in dogs is not as well-understood as it is in humans, dogs can show signs of depression like loss of appetite, lethargy, and loss of interest in activities they previously enjoyed. Fluoxetine can help improve these symptoms by boosting mood through increased serotonin levels.

Fluoxetine Side Effects

Fluoxetine, like any medication, can have side effects. Not all dogs will experience these side effects, but it's important to be aware of them and monitor your dog closely while they are taking this medication. 

More common fluoxetine for dogs side effects include:

• Reduced appetite
• Lethargy
• Nausea
• Vomiting
• Diarrhea²

These more common side effects of fluoxetine are typically not severe. If your dog experiences gastrointestinal side effects, you can try administering fluoxetine with their food. If your dog loses their appetite, contact your veterinarian ASAP.⁶

Less common fluoxetine for dogs side effects include:

• Persistent appetite loss
• Tremors
• Increase in aggression
• Increase in anxious behavior
• Insomnia⁶ 

These side effects of fluoxetine are considered more serious. If your dog displays any of the above, it’s crucial to contact your veterinarian as soon as possible.

Fluoxetine Dosage For Dogs

According to the Merck Veterinary Manual, the appropriate fluoxetine dosage for dogs is 0.5 to 1.4 milligrams per pound of body weight per day or 1 to 2 milligrams per kilogram of body weight per day.⁷ However, the most suitable dosage of fluoxetine for your dog will depend on a number of factors.

Veterinarians will generally consider the below factors when prescribing fluoxetine for dogs:

• Weight: The correct dosage of fluoxetine is often determined based on your dog's body weight. Larger dogs typically need higher doses than smaller dogs to achieve the same effect. Overdosing or underdosing can lead to serious complications.
• Age: Depending on your dog’s age, they may also need different doses of fluoxetine. Age affects a dog's ability to metabolize drugs. Puppies and elderly dogs generally have slower metabolisms and may require adjusted doses. 
• Breed: While no specific dog breeds are known to have inherent sensitivities or resistance to fluoxetine, certain breeds are more susceptible to the behavioral conditions that are treated with this medication. Lagotto Romagnolos and Wheaten Terriers, for example, are dog breeds more prone to anxiety. 
• Health condition: Your dog’s health condition may affect how they process and eliminate medications, which can impact dosage requirements. For example, dogs with a history of seizures, epilepsy, liver disease, diabetes, or kidney disease may not be suitable candidates for fluoxetine, but it is ultimately up to the veterinarian’s discretion.⁶ 
• Medication format: Fluoxetine is available in capsule, tablet, and liquid formats. Depending on which format your dog is taking, they may need different dosages.⁶
• Drug interactions: Fluoxetine can interact negatively with a number of other medications, including other SSRIs, monoamine oxidase inhibitors, certain antifungal medications, and some flea and tick treatments.⁶ 

Are There Alternatives To Fluoxetine For Dogs?

If your veterinarian determines that fluoxetine may not be the most suitable medication for your dog or if your dog experiences a negative reaction to fluoxetine, there are several alternative options available. Here are some commonly prescribed medications for addressing behavioral issues in dogs:

• Clomipramine (Clomicalm): This is a tricyclic antidepressant often used for separation anxiety in dogs.
• Sertraline (Zoloft): This SSRI is sometimes used to treat depression and anxiety disorders in dogs.
• Alprazolam (Xanax) and diazepam (Valium): These benzodiazepines can be used for acute anxiety episodes, such as those caused by thunderstorms or fireworks.

Additionally, non-pharmacological treatments can also be beneficial for dogs dealing with anxiety or behavioral problems. These may include behavior modification therapy, increased exercise, and a more structured environment. Certain dietary supplements, like L-theanine and probiotic powders that contain Bifidobacterium longum, may also be recommended by your vet.

Fluoxetine For Dogs: FAQs

How long does it take for fluoxetine to work in dogs?

Fluoxetine can take between 4 to 6 weeks to show noticeable improvements in a dog's behavior. This is because it works by adjusting the levels of serotonin in the brain, a process that takes some time to become effective.

What time of day should I give my dog fluoxetine?

The administration of fluoxetine to your dog should be consistent, given at the same time each day. This could be in the morning or evening, as long as it is consistent. Your vet may advise a specific time based on your dog's habits and the presence of any other treatments or medications.

Can fluoxetine make anxiety worse in dogs?

While fluoxetine is generally used to treat anxiety and obsessive behaviors in dogs, it can initially increase anxiety in some dogs. This is often a temporary side effect as your dog's body adjusts to the medication. If this effect persists or causes significant discomfort, consult with your veterinarian.

Are there any dogs that shouldn't take fluoxetine?

Not all dogs are good candidates for fluoxetine. Dogs with liver disease, seizures, diabetes, or who are pregnant or nursing should avoid fluoxetine unless specifically recommended by a veterinarian.

Final Notes 

Overall, fluoxetine can be a valuable tool in managing behavioral issues in dogs when used under the guidance of a veterinarian. This medication has shown promising results in reducing anxiety, compulsive behaviors, and aggression, ultimately leading to an improved quality of life for both dogs and their owners. However, it's important to remember that fluoxetine is just one aspect of a comprehensive treatment plan. To achieve the best outcomes, it should be combined with behavior modification and ongoing support.

If you have more questions about fluoxetine for dogs, or if you're considering exploring online prescription options for your pup, speak with a Dutch veterinarian. With Dutch, you can access expert veterinary advice without stepping out of your home. Moreover, we offer a seamless service that delivers prescribed medications right to your doorstep.