Fluoxetine HCl

What is this medication for?

• Separation anxiety (FDA-approved w/ behavior modification), compulsive/OCD behaviors, aggression
• Urine spraying/marking, aggression, anxiety, compulsive behaviors

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Always pair with a structured behavior-modification program — medication alone is not expected to resolve the underlying behavioral issue.
• Do not stop abruptly after long-term use — taper.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Anorexia (often transient), low energy/tiredness, stomach/intestinal effects, irritability/hyperactivity, panting (Common)
• Aggression in previously non-aggressive dogs (Reported)
• Anxiety/irritability, sleep disturbance, loss of appetite, altered elimination (Reported)

Worth a phone call to your veterinarian

• Any new symptom that worries you.

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Seizures (Reported in field trials, causality unclear)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Known hypersensitivity; concurrent MAO inhibitors (5-week washout after fluoxetine, 2-week before starting selegiline)
• has or has had: Dogs with epilepsy/seizure history (label warning); do not combine with seizure-threshold-lowering drugs (acepromazine, chlorpromazine); caution in diabetes mellitus; reduce dose in severe hepatic impairment

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • MAO inhibitors (amitraz, selegiline)
  • Tramadol
  • TCAs (clomipramine, amitriptyline)
  • Trazodone
  • Diazepam, alprazolam
  • Propranolol, metoprolol
  • Warfarin

Storage and handling

Room temperature, well-closed/light-resistant containers.

Good to know

• Always pair with a structured behavior-modification program — medication alone is not expected to resolve the underlying behavioral issue.
• Do not stop abruptly after long-term use — taper.
• Do not use in dogs with a seizure history without careful risk discussion — this is an explicit label caution, not just a general one.