Fluoxetine in Dogs

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) that is FDA-approved for treating separation anxiety in dogs. It is also sometimes prescribed for aggressive dogs, general anxiety, and compulsive disorders in dogs.

Fluoxetine is commonly known under its brand names Reconcile (chewable veterinary tablet), Prozac, and Sarafem.

Medication for Aggressive Dogs

If you’re looking for medication for an aggressive dog, fluoxetine is a strong choice. Be advised, however, that aggression in dogs is extremely difficult to treat successfully, even with the help of medication and compliance with a professionally guided behavior-modification program from a fear-free trainer.

Aggression in dogs as a behavior issue always carries a guarded prognosis. Even with improvement, these dogs can still be dangerous and should always be carefully managed with the safety of both humans and other dogs in mind.

Fluoxetine for Dogs Dosage

The FDA-approved fluoxetine dosage for dogs is 1 to 2 mg/kg by mouth once a day. With safe rounding, this translates to 5 to 10 mg for a 10-lb. dog, 20 to 40 mg for a 50-lb. dog, and 40 to 80 mg for a 90-lb. dog. Your veterinarian usually will start low, even as low as 0.5 mg/kg once a day, for the first couple of weeks to minimize side effects and allow your dog to acclimate to the medication. The dose is ramped up from there, as needed.

Fluoxetine for Dogs Side Effects

Reported fluoxetine side effects in dogs include:

• Lethargy
• Vomiting
• Diarrhea
• Lack of appetite

Observed possible side effects include:

• Seizures (cause and effect is not proven)
• Unusual aggressive behavior
• Restlessness
• Shaking
• Panting
• Confusion
• Vocalizing
• Drooling

If your dog exhibits any of these side effects, contact your veterinarian. Sometimes starting with a lower dose resolves the issue, with subsequent higher dosages better tolerated. Fluoxetine can be given with or without food, so if your dog vomits or stops eating after trying it one way, you may be advised to try it the other way. See also “Anti-Anxiety Medications for Dogs.”