Selective serotonin reuptake inhibitor (SSRI) · For Dogs

Prozac dosage reference for dogs (Fluoxetine)

This page's standard weight-based reference is 1.5 mg per kg (0.68 mg per lb), with Once daily recorded as the reference frequency. Use the calculator to see the arithmetic for your dog's weight, then confirm the indication, product, and actual dose with a veterinarian.

Onset: 4-6 weeks for full behavioral effect
Duration: 24 hours per dose
Class: Selective serotonin reuptake inhibitor (SSRI)

Weight-based calculator estimate from the references listed on this page. This page has not been independently DVM-reviewed — see our methodology .

This information is for educational purposes only. Always consult your veterinarian before giving medication to your pet. Do not use this calculator for emergencies, overdoses, pregnancy, very young animals, very old animals, pets with liver/kidney disease, or pets taking multiple medications.

Each medication page lists the references recorded for its data. The calculator math and editorial presentation are maintained by PetDosageChart; a page is independently DVM-reviewed only when a named reviewer byline appears. See our methodology and limitations.

Fluoxetine (often known by brand names such as Prozac and Reconcile) is a selective serotonin reuptake inhibitor (SSRI) commonly used in veterinary medicine for Separation anxiety, Compulsive behaviors, Fear-based aggression, and Thunderstorm and noise phobias. Understanding the correct dosage, administration, and potential side effects of Fluoxetine is critical for your dog’s safety and well-being.

A typical Fluoxetine dose for dogs is around 1.5 mg/kg Once daily, within a usual range of 1-2 mg/kg. Available forms include Tablet, Capsule, and Oral liquid.

Calculator Warning: Use this only as an educational estimate. Your veterinarian may prescribe a different dose based on your pet’s condition, age, weight, other medications, and medical history.

Fluoxetine Dosage Calculator for Dogs

Enter your dog’s weight below to estimate the Fluoxetine dose from the 1.5 mg/kg guideline. Your veterinarian may adjust it for your dog’s age, condition, and other medications, so treat the result as an educational starting point, not a prescription.

Dosage Calculator · 01

Enter your dog's weight

Quick Dosage Chart

Typical Fluoxetine amounts for common dog weights, for quick reference:

Dosage Chart · 02

Prozac weight-based reference chart for dogs

Scroll sideways to see full table

Weight	Lower Reference	Standard Reference	Upper Reference	Frequency
5 lbs (2.3 kg)	2.3 mg	3.4 mg	4.6 mg	Once daily
10 lbs (4.5 kg)	4.5 mg	6.8 mg	9.0 mg (10mg tablet)	Once daily
15 lbs (6.8 kg)	6.8 mg	10.2 mg (10mg tablet)	13.6 mg	Once daily
20 lbs (9.1 kg)	9.1 mg (10mg tablet)	13.6 mg	18.2 mg (2 × 10mg)	Once daily
25 lbs (11.3 kg)	11.3 mg (10mg tablet)	17.0 mg	22.6 mg	Once daily
30 lbs (13.6 kg)	13.6 mg	20.4 mg (2 × 10mg)	27.2 mg	Once daily
40 lbs (18.1 kg)	18.1 mg (2 × 10mg)	27.2 mg	36.2 mg	Once daily
50 lbs (22.7 kg)	22.7 mg	34.0 mg	45.4 mg	Once daily
60 lbs (27.2 kg)	27.2 mg	40.8 mg (4 × 10mg)	54.4 mg	Once daily
70 lbs (31.7 kg)	31.7 mg (3 × 10mg)	47.5 mg (5 × 10mg)	63.4 mg	Once daily
80 lbs (36.3 kg)	36.3 mg	54.4 mg	72.6 mg	Once daily
90 lbs (40.8 kg)	40.8 mg (4 × 10mg)	61.2 mg (6 × 10mg)	81.6 mg (8 × 10mg)	Once daily
100 lbs (45.4 kg)	45.4 mg	68.1 mg (7 × 10mg)	90.8 mg (9 × 10mg)	Once daily
120 lbs (54.4 kg)	54.4 mg	81.6 mg (8 × 10mg)	108.8 mg (11 × 10mg)	Once daily
150 lbs (68 kg)	68.0 mg (7 × 10mg)	102.0 mg (10 × 10mg)	136.0 mg	Once daily

Parenthetical tablet amounts are arithmetic comparisons only. They do not account for scoring, release type, concentration, product labeling, or whether this medication is appropriate for an individual animal.

By Weight

Prozac reference by dog weight

Choose a common weight to open its optional reference page. Use the main medication calculator for a different exact weight.

Common-weight pages are convenience views of the same educational reference, not separate medical recommendations.

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How to Give Fluoxetine to Your Dog

Give fluoxetine once daily by mouth, with or without food, though giving with food may reduce stomach upset. Administer at the same time each day for consistent blood levels. Tablets can be hidden in a small treat or pill pocket. Do not crush capsules. Allow 4-6 weeks to assess effectiveness before requesting a dose change.

It is generally recommended to give Fluoxetine with food to help reduce stomach upset. It may interact with MAO inhibitors — risk of serotonin syndrome (potentially fatal), Tramadol — increased serotonin syndrome risk, Trazodone — additive serotonin effects, Diazepam and other benzodiazepines — increased sedation, and Cyproheptadine may reduce effectiveness.

Side Effects and Safety

Common side effects include Decreased appetite, Lethargy or sedation, GI upset (vomiting, diarrhea), and Restlessness or agitation during first week. More serious side effects can occur, such as Serotonin syndrome (tremors, hyperthermia, agitation), Seizures, Severe aggression changes, and Liver enzyme elevation.

Cautions · 12

When Prozac should be used with caution or avoided

Some dogs should not take Prozac, or need a different dose and closer monitoring. Tell your veterinarian about your pet's full health history and every other medication or supplement they take before giving Prozac.

Use with MAO inhibitors (e.g., selegiline, amitraz)
Known hypersensitivity to fluoxetine
Severe liver disease
History of seizures (use with caution)

Interactions · 13

Prozac drug interactions

Prozac can interact with other drugs. This list is not complete — always give your veterinarian a full list of your dog's medications and supplements.

MAO inhibitors — risk of serotonin syndrome (potentially fatal)

Tramadol — increased serotonin syndrome risk

Trazodone — additive serotonin effects

Diazepam and other benzodiazepines — increased sedation

Cyproheptadine may reduce effectiveness

Calculator Limits · 14

When not to use this calculator

This calculator gives a general educational estimate for a healthy adult dog at a known weight. Do not rely on it in these situations — talk to your veterinarian instead:

In an emergency, or after accidental ingestion or a suspected overdose
For pregnant or nursing pets
For very young or very old dogs
For pets with liver disease, kidney disease, or another chronic illness
For pets taking several medications at once
When you are not sure of your dog's current, accurate weight
For combination products that contain additional active ingredients

Overdose · 15

Suspected overdose: what to do

If you think your dog had too much Prozac, or swallowed any medication by accident, act right away. Do not wait for symptoms to appear.

Call your veterinarian or the nearest emergency animal hospital.
ASPCA Animal Poison Control Center: (888) 426-4435
Pet Poison Helpline: (855) 764-7661

A consultation fee may apply to the poison hotlines. Have the medication packaging ready, and note how much your pet may have taken and when. Do not try to make your pet vomit unless a veterinarian tells you to.

When to Call the Vet

If your dog experiences any of the following, contact your veterinarian or an emergency clinic immediately:

Tremors, rapid breathing, or hyperthermia (signs of serotonin syndrome)
Seizure activity
Severe or sudden aggression changes
Persistent vomiting or complete refusal to eat for more than 48 hours
Significant lethargy or inability to rouse

Frequently Asked Questions

Frequently Asked · 07

Questions about this medication

How long does fluoxetine take to work in dogs?

Fluoxetine typically takes 4-6 weeks to reach full therapeutic effect in dogs. Some improvement may be noticed within 1-2 weeks, but the full behavioral benefits require consistent daily dosing over several weeks. Do not discontinue early because you see no immediate results.

Can I stop fluoxetine for my dog suddenly?

No. Abrupt discontinuation can cause withdrawal symptoms including irritability, GI upset, and worsening anxiety. Fluoxetine should be tapered gradually over 2-4 weeks under veterinary guidance to avoid rebound behavioral problems.

Does fluoxetine make dogs sleepy?

Some dogs experience mild lethargy or sedation, especially during the first 1-2 weeks. This usually resolves as the body adjusts. If sedation is severe or persistent, contact your veterinarian for a dose adjustment.

Is fluoxetine the same as Prozac for dogs?

Yes, fluoxetine is the generic name for Prozac. Reconcile is the FDA-approved veterinary brand of fluoxetine specifically formulated for dogs. Human generic fluoxetine is also commonly prescribed by veterinarians at appropriate canine doses.

Can fluoxetine be used with behavior training for dogs?

Absolutely. Fluoxetine works best when combined with behavior modification training. The medication reduces the baseline anxiety level so the dog can learn more effectively. It is not intended as a standalone solution but as part of a comprehensive behavioral treatment plan.

Use This Guide Safely · 08

What weight alone cannot tell you

The calculator performs one narrow job: it multiplies your dog's weight by the lower, standard, and upper mg/kg values recorded for Prozac. It cannot decide whether this drug, indication, formulation, or schedule is appropriate for an individual animal.

Context in this medication record

Commonly listed uses: Separation anxiety, Compulsive behaviors, Fear-based aggression, Thunderstorm and noise phobias
Recorded forms: Tablet, Capsule, Oral liquid
Reference timing: Once daily; onset 4-6 weeks for full behavioral effect; duration 24 hours per dose

Individual checks a calculator cannot perform

Confirm the diagnosis and the reason this medication is being considered.
Match the exact product, concentration, route, and whether a tablet may be split.
Account for age, pregnancy, organ function, genetics, allergies, and prior reactions.
Review every prescription, over-the-counter product, and supplement your pet takes.

Recorded cautions

Use with MAO inhibitors (e.g., selegiline, amitraz); Known hypersensitivity to fluoxetine; Severe liver disease; History of seizures (use with caution).

Recorded interactions

MAO inhibitors — risk of serotonin syndrome (potentially fatal); Tramadol — increased serotonin syndrome risk; Trazodone — additive serotonin effects; Diazepam and other benzodiazepines — increased sedation; Cyproheptadine may reduce effectiveness.

These lists reproduce the structured record used by this page and may not be exhaustive. Show your veterinarian the product label and your dog's complete medication list before acting on a number.

Related · 08

Related medications for dogs

Sources · 09

Sources & references

The structured medication record behind this page names the references below. The links open the publisher or official resource; they do not turn this page into a prescription for an individual animal.

Plumb's Veterinary Drug Handbook — listed in this medication's source record.
Merck Veterinary Manual — listed in this medication's source record.
DailyMed label search for Fluoxetine — check current product and formulation labels; some veterinary uses may be off-label.

Source names are shown at the record level; passage-level page and label citations are still being added. Read our methodology and limitations.

Transparency · 11

How this page was made

This page's structured medication record includes Plumb's Veterinary Drug Handbook among its source names. PetDosageChart applies the record's mg/kg values to the entered weight and presents the arithmetic result. A source record is not the same as an individualized prescription or an independent clinical review.

Sources cited: Plumb's Veterinary Drug Handbook
Merck Veterinary Manual
Calculator formula: Doses scale linearly from a standard basis of 1.5 mg per kg (0.68 mg per lb) of body weight, given Once daily. The calculator multiplies that basis by your dog's weight and shows an arithmetic comparison with recorded tablet sizes. That comparison does not determine whether a tablet is scored, splittable, or appropriate for your pet.
Editorial owner: Prepared and maintained by the PetDosageChart editorial team, a software-led publisher and not a veterinary practice.
DVM review status: Not independently DVM-reviewed. A named reviewer and review date appear here only after a confirmed review.

More on our methodology and editorial process — how we source, calculate, and review dogs dosage data.

Safety · 10

More resources

Pet Medication Safety Hub — What's safe, what's dangerous, and emergency signs
How we calculate dosages — Our sources, math, and review process
Printable emergency checklist — One-page reference for your fridge or first aid kit