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PetDosageChart

Selective serotonin reuptake inhibitor (SSRI) · For Dogs

How much Prozac (Fluoxetine) can I give my dog?

Standard Prozac dose for dogs is 1.5 mg per kg (0.68 mg per lb), given Once daily. Use the calculator below for your dog's exact weight, or jump to the weight-by-weight chart.

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

Calculator estimate from Plumb’s Veterinary Drug Handbook. Not yet vet-reviewed — see our methodology .

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. Sourced from Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

Dosage Calculator · 01

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By Weight

Prozac dose by dog weight

Pick your dog's weight to jump to a dedicated page with the dose, frequency, safety notes, and FAQ for that size.

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Dosage Chart · 02

Prozac dosage for dogs by weight

Scroll sideways to see full table

Weight Low Dose Standard Max Safe Frequency
5 lbs (2.3 kg) 2.5mg 3.5mg 4.5mg Once daily
10 lbs (4.5 kg) 4.5mg 7mg 9mg (10mg tablet) Once daily
15 lbs (6.8 kg) 7mg 10mg (10mg tablet) 13.5mg Once daily
20 lbs (9.1 kg) 9mg (10mg tablet) 13.5mg 18mg (2 × 10mg) Once daily
25 lbs (11.3 kg) 11.5mg (10mg tablet) 17mg 22.5mg Once daily
30 lbs (13.6 kg) 13.5mg 20.5mg (2 × 10mg) 27mg Once daily
40 lbs (18.1 kg) 18mg (2 × 10mg) 27mg 36mg Once daily
50 lbs (22.7 kg) 22.5mg 34mg 45.5mg Once daily
60 lbs (27.2 kg) 27mg 41mg (4 × 10mg) 54.5mg Once daily
70 lbs (31.7 kg) 31.5mg (3 × 10mg) 47.5mg (5 × 10mg) 63.5mg Once daily
80 lbs (36.3 kg) 36.5mg 54.5mg 72.5mg Once daily
90 lbs (40.8 kg) 41mg (4 × 10mg) 61mg (6 × 10mg) 81.5mg (8 × 10mg) Once daily
100 lbs (45.4 kg) 45.5mg 68mg (7 × 10mg) 91mg (9 × 10mg) Once daily
120 lbs (54.4 kg) 54.5mg 81.5mg (8 × 10mg) 109mg (11 × 10mg) Once daily
150 lbs (68 kg) 68mg (7 × 10mg) 102mg (10 × 10mg) 136mg Once daily

Common Uses · 03

What is Prozac (Fluoxetine) used for in dogs?

Separation anxiety Compulsive behaviors Fear-based aggression Thunderstorm and noise phobias

Administration · 04

How to give Prozac 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.

Available Forms

Tablet, Capsule, Oral liquid

Give with Food?

Yes — give with food

Side Effects · 05

Side effects of Prozac in dogs

Common side effects

Decreased appetite
Lethargy or sedation
GI upset (vomiting, diarrhea)
Restlessness or agitation during first week

Serious side effects — call your vet

  • Serotonin syndrome (tremors, hyperthermia, agitation)
  • Seizures
  • Severe aggression changes
  • Liver enzyme elevation

Emergency · 06

When to call the vet

Call your vet immediately if your dog shows any of these signs:

  • 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

For Cats

Looking for Prozac dosage for cats?

View the Prozac dosage chart and calculator for cats.

Related · 08

Related medications for dogs

Sources · 09

Sources & references

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Fluoxetine.

Read more about our methodology and how we calculate dosages.

Transparency · 11

How this page was made

Sourced from Plumb's Veterinary Drug Handbook, the reference used in US vet schools. Every dose, frequency, and tablet count on this page is generated from that data, then checked against the published references below.

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 rounds to the closest available tablet size.
Last-reviewed status
Automated from Plumb’s, not yet vet-reviewed.

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

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.

Safety · 10

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