Pet Medication 101: Prozac

Estimated Reading Time 2 minutes
Pet Medication 101: Prozac

It’s important to understand a medication’s uses and side effects before giving it to your pet. This medication info sheet is meant to give you a good understanding of what Prozac (fluoxetine) is used for, how it works, and potential side effects in cats and dogs. Always consult a veterinarian before giving your pet any medication.

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

  • Professional vet advice online
  • Low-cost video vet consultations
  • Open 24 hours a day, 365 days a year

1. Drug Name:

fluoxetine hydrochloride

2. Brand Names:

Reconcile, Prozac, Olena, Prozep, Prozet, Zactin, Lovan, Sarafem, Selfemra

3. How Dispensed:


4. Forms:

Veterinary formulation: 8mg, 16mg, 32mg, 64mg chewable tablets

Human formulations: 10mg, 20mg, 40mg, 60mg capsules; 90mg delayed-release capsules; 10mg, 15mg, 20mg, 40mg, 60mg oral tablets; 20mg/5mL oral solution

25mg and 50mg combination products containing olanzapine

5. Drug Type/Class:

Selective serotonin reuptake inhibitor (SSRI); behavior modifier

6. Uses in Dogs and Cats:

Used in dogs for separation anxiety, and in dogs and cats for aggression, generalized anxiety, compulsive behavior, and inappropriate urination.

7. How it Works:

Fluoxetine increases serotonin activity. Serotonin is a chemical that stabilizes mood, feelings of well-being and happiness, as well as aids in sleeping and digestion.

8. Side Effects and/or Signs of Overdose:

Side effects include decreased energy levels, decreased appetite, and gastrointestinal signs such as vomiting, diarrhea, and excessive salivation. Incoordination can also occur. Cat owners reported constipation and urinary retention.

Signs of overdose include excessive sedation. Very high doses can cause serotonin syndrome, a serious drug reaction that can lead to many adverse effects including diarrhea, high heart rate, high respiratory rate, hypertension, tremors, seizures, abnormally high body temperatures, and even coma or organ failure in the most severe cases.

9. Drug Interactions:

  • Coadministration with other SSRIs or drugs that increase serotonin levels increase the risk of serotonin syndrome
  • Chlorpheniramine
  • Opiates
  • Tramadol
  • Trazodone
  • Clomipramine
  • Amphetamines
  • Diazepam
  • Monoamine oxidase inhibitors (selegiline, amitraz)
  • Quinidine

10. Cautionary Statements:

  • Fluoxetine should not be used in patients with exposure to other drugs that increase serotonin within 2 weeks
  • In some rare instances, fluoxetine increases aggressive behavior so should be used with caution when initiating therapy in aggressive patients
  • Full effects may take 4-8 weeks in some patients
  • Fluoxetine should be tapered over 3-4 weeks and not discontinued abruptly. Gradual withdrawal is recommended to decrease unwanted symptoms such as agitation, anxiety, and confusion
  • Appetite and body weight should be monitored closely
  • Use with caution in patients with bleeding disorders and kidney disease

Read more:

Separation Anxiety in Cats

How to Find the Right Dog Trainer

Puppy Training Toolbox

Need to speak with a veterinarian regarding your pet's medication or another condition?

Click here to schedule a video consult to speak to one of our vets. You can also download the FirstVet app from the Apple App Store and Google Play Stores.

Are you concerned about your pet?

Book a video consultation with an experienced veterinarian within minutes.

Get started
  • Low-cost video vet consultations, 24 hours a day Low-cost video vet consultations, 24 hours a day
  • Experienced, licensed vets Experienced, licensed vets
  • Over 700,000 satisfied pet owners Over 700,000 satisfied pet owners
Low cost consultations, 24 hours a day.Low cost consultations, 24 hours a day.

With FirstVet, the vet clinic and pet shop are only one tap away. Get fast advice, trusted care and the right pet supplies – every day, all year round.


FirstVet Inc

900 3rd Ave 29th Floor


New York