Studies have shown fluoxetine (Prozac, Reconcile), when prescribed by your veterinarian, is usually a safe and effective medicine for dogs for the treatment of behavioral disorders like separation anxiety. It is most effective when used in conjunction with a behavior modification plan for your pet.

Do not give your dog Prozac or fluoxetine unless it has been prescribed by your veterinarian.

Specific chewable formulations of fluoxetine for dogs are available and approved by the FDA.

• Reconcile is a brand name product specifically developed for dogs and is available in 8, 16, 32, and 64 mg strength chewable tablets. It can be given with or without food.
• Reconcile may be preferable due to the chewable formulation for dogs. It is for animal use only.

Prozac (generic name: fluoxetine) is a medicine originally developed for humans as an antidepressant. This formulation of fluoxetine may also be prescribed by your vet but is not specifically FDA-approved for use in animals. It comes in a capsule or liquid form.

Prozac side effects in dogs

As with any medicine, side effects with Prozac may occur in dogs, and safety depends on your dog’s health status and correct use and dose of the medicine. The dose must be determined based on your dog’s weight and other health conditions. Your vet will need to check for any possible drug interactions, too.

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) prescribed in veterinary medicine to help with separation anxiety problems in dogs. It is used in conjunction with a behavior modification plan. Your veterinarian may use this medicine for other canine conditions as well.

Commonly reported side effects with fluoxetine in dogs include:

• weight loss
• depression
• lethargy, sleepiness
• restlessness
• panting
• loss of appetite
• vomiting
• diarrhea

Weight loss can be a common side effect with fluoxetine when used in dogs. Studies with Reconcile (fluoxetine) chewable tablets have shown weight loss occurred in 29.6% (58 / 196) of dogs treated with fluoxetine and 13% (24 / 185) of dogs in the control group.

In studies, dogs who lost weight most frequently lost 5% to 10% of their initial weight (22.5% of the fluoxetine group and 10.8% of the control group).

Serious side effects may include:

• seizures
• tremors
• persistent weight loss or loss of appetite
• aggressive behavior
• ongoing restless or inability to sleep
• serotonin syndrome

Tell your veterinarian if your dog has ever had seizures. Dogs who have a history of seizures should not receive fluoxetine. Seizures may occur in dogs treated with fluoxetine, even in dogs without a history of epilepsy or seizures.

Seizures have been reported as a serious or fatal side effect in dogs when fluoxetine (brand name: Reconcile) was administered. Fatal seizures are uncommon, and some studies have shown that the dogs had additional or other causes for seizures.

• In one study, 3 out of 117 dogs who received fluoxetine (Reconcile chewable tablets) and 1 out of 112 dogs in the control group (given a tablet with no medicine) experienced a seizure. One dog receiving fluoxetine died from a serious seizure 6 months after the first seizure.
• In another study, 1 of 99 dogs treated with fluoxetine (Reconcile chewable tablets) and 1 of 99 dogs receiving the control experienced a seizure. Seizures occurred 9 and 27 days after the start of therapy, respectively. The dog treated with fluoxetine was subsequently diagnosed with vestibular disease (located in the inner ear and middle ear and causing balance problems, that are usually temporary).

If your dog experiences any serious side effects, or other side effects that concern you, contact your veterinarian right away.

Let your vet know about all the medicines or supplements your dog takes, including any vitamins or herbal-type treatments. Plus, if your dog has ever had an allergy to any medicine, tell your vet what it was. Tell them if your dog has liver disease or diabetes.

How well does fluoxetine work in dogs for separation anxiety?

The safety and effectiveness of fluoxetine (brand name: Reconcile) for separation anxiety in dogs was shown in an 8-week long study.

• At the end of the 8 weeks, 73% of dogs treated with Reconcile showed significant improvements when compared to behavior modification alone (51%).
• In the first week, 42% of dogs showed improvement compared to 18% of dogs in behavior modification alone.
• Fluoxetine treatment may help make your dog more receptive to behavioral training.

If no improvement is seen in 8 weeks, your veterinarian should reevaluate therapy.

Prozac, when used in dogs, is usually given once per day.

• The recommended dose of fluoxetine chewable tablets for dogs (brand: Reconcile) is 1 to 2 mg per kg (0.5 to 0.9 mg per lb) administered once daily, in conjunction with a behavior modification plan. Follow the dose prescribed by your vet exactly.
• Prozac or the generic version known as fluoxetine can also be used, but is not chewable. Liquid forms of fluoxetine are also available.

Results with fluoxetine may require up to 4 to 6 weeks for the full effect. In the interim, your vet may prescribe other acting agents that work more quickly, if needed.

Do not stop Prozac treatment in your dog without speaking to your vet first. Your vet may want you to slowly stop the medicine.

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How does fluoxetine work in dogs?

• Fluoxetine works by helping to increase levels of serotonin. Serotonin is a neurotransmitter (or a chemical messenger) that helps in controlling anxiety.
• Low levels of serotonin may impair communication and increase anxiety symptoms.
• Fluoxetine does not act as a sedative.

Just like humans, dogs can experience anxiety, including separation anxiety. Prozac (fluoxetine) has been shown to help dogs overcome separation anxiety in studies.

Fluoxetine (Prozac) is in a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). It has been used for many years to help with anxiety in humans and can be used in dogs when prescribed by your veterinarian.

Does my dog need fluoxetine (Prozac) for separation anxiety?

Separation anxiety may occur when the dog is left alone, such as when the owner goes to work or the animal is separated from an important person.

Symptoms of anxiety in dogs can include:

• excessive barking, howling, whining
• excessive drooling, licking
• hiding
• pacing back and forth, restlessness
• destruction of property, especially around entry and exit areas
• urination or defecation inside the house
• aggression
• loss of appetite
• repetitive or compulsive behaviors

Symptoms may begin within 15 to 30 minutes of the owner departing, or when the owner prepares to depart, such as gathering items, putting on shoes, getting keys, and going towards the door. Once the owner returns home, the dog may crave constant attention from their owners any may find it difficult to settle down.

Contact your veterinarian if you notice any of these signs in your dog. Causes of anxiety should be determined to help choose the right treatment. For example, short-term anxiety, such as loud noises (thunderstorms, lightning, fireworks) or car rides may need a different, and only intermittent medicine.

Your vet can examine your dog, review their symptoms and determine if fluoxetine is the right medicine.

What causes separation anxiety in dogs?

Dogs may be at risk for separation anxiety for a variety of reasons, including predisposition to anxiety, environmental factors, and prior learning and experiences.

Life changes, like a move to a new home or loss of a family member (death, divorce, loss of another pet, child moves out of house) can cause separation anxiety.

Some breeds may be more likely to suffer from separation anxiety. There is some evidence that suggests shelter dogs may be more prone to separation anxiety because they were abandoned or lost an important person in the past.

Sometimes dogs become so attached to their owners (hyperattached) that any type of separation can cause anxiety. Older, senior dogs may have a greater risk of developing separation anxiety, too.

Fluoxetine treatment for dogs with separation anxiety is typically combined with a behavior modification plan for dogs.

• A typical behavior modification plan involves the pet owner initiating training for the dog. This may include rewarding appropriate behavior, coming and going in a manner that does not elicit inappropriate responses from the dog, and teaching the dog to be content while alone.
• Ongoing behavioral modification may be recommended to prevent a recurrence of signs of separation anxiety.
• Never punish your dog for house soiling or destruction as it will increase the anxiety your dog feels when anticipating your return to the house.

Other types of anxiety in canines includes noise sensitivity and general fearfulness (for example: (toward strangers, other dogs, or in new surroundings).

Can my dog overdose on fluoxetine (Prozac)?

Fluoxetine (brand examples: Prozac, Reconcile) or other SSRIs can be toxic to your dog if ingested in significant amounts. In dogs, toxicity, seizures and possible death can be seen with excessive fluoxetine doses.

If your dog has accidentally ingested ANY amount of fluoxetine, contact your veterinarian right away or call the ASPCA Animal Poison Control Center Hotline at 1-(888) 426-4435. You may also contact a local emergency veterinarian facility in your area.

Always consult with your veterinarian about any medicine for your dog or other pet. Human prescription drugs and over-the-counter (OTC) medicine may not be safe for your pet and can cause harm. This is not all the information you need to know about fluoxetine (Prozac, Reconcile) for dogs and does not replace any information or directions supplied by your veterinarian.

References

• Simpson BS et al. Effects of Reconcile (fluoxetine) chewable tablets plus behavior management for canine separation anxiety. Vet Therapeut. 2007;8(1)18.
• Brooks D. Fluoxetine (Reconcile®, Prozac). Revised 3/21/2023. Accessed June 29, 2023 at https://veterinarypartner.vin.com/
• Prozac for dogs. Veterinary Place. Accessed June 29, 2023 at https://www.veterinaryplace.com/dog-medicine/prozac-for-dogs
• Gollakner R. Fluoxetine. Accessed June 29, 2023 at https://vcahospitals.com/know-your-pet/fluoxetine
• Reconcile Prescribing Information. Drugs.com. Accessed June 29, 2023 at https://www.drugs.com/pro/reconcile.html#s-42232-9
• Reconcile Chewable Tablets. Drugs.com. Accessed June 29, 2023 at https://www.drugs.com/vet/reconcile-chewable-tablets.html
• Reconcile digital clinic brochure. PRN Pharmaceuticals. Accessed June 29, 2023 at https://www.reconcile.com/wp-content/uploads/2021/10/Reconcile-Digital-Clinic-Brochure.pdf
• Lansberg G, Denenberg S. Behavioral Problems of Dogs. Merck Manual Veterinary Manual. Accessed June 29, 2023 at https://www.merckvetmanual.com/behavior/normal-social-behavior-and-behavioral-problems-of-domestic-animals/behavioral-problems-of-dogs
• Separation Anxiety in Dogs. American Kennel Club. Updated: Dec 09, 2018. Accessed June 29, 2023 at https://www.akc.org/expert-advice/coaching/separation-anxiety-in-dogs/
• Kriss R. Understanding, Preventing, and Treating Dog Anxiety. Updated: Feb 03, 2023. Accessed June 29, 2023 https://www.akc.org/expert-advice/health/treating-dog-anxiety/
• American College of Veterinary Medicine. Fluoxetine. Accessed June 29, 2023 at https://vetmeds.org/pet-poison-control-list/Fluoxetine/

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