Suspect poisoning? US: ASPCA Poison Control (888) 426-4435 · UK: 01202 509 000 · Severe symptoms → nearest emergency vet now.

Antidepressant (SSRI) Poisoning

Antidepressants are among the most common pet poisonings. Even a single pill of some brands can cause serotonin syndrome in a small dog.

Treat this as a potential emergency — not a "wait and see" situation.
Contact your vet before symptoms even appear.

US: ASPCA Animal Poison Control (888) 426-4435 · Pet Poison Helpline (855) 764-7661

UK: Veterinary Poisons Information Service 01202 509 000

What is serotonin syndrome?

Drugs such as SSRIs (fluoxetine/Prozac, sertraline), SNRIs and tricyclics raise serotonin levels. When a pet swallows too much, the excess causes agitation, tremors and a dangerously high body temperature — serotonin syndrome.

Why speed matters

Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.

Symptoms of antidepressants poisoning

  • Restlessness, agitation, pacing
  • Tremors or shaking, muscle twitching
  • Very high body temperature, panting
  • Vomiting, diarrhoea
  • Seizures, severe rigidity (emergency)

What to do right now

  1. Call your vet or poison control immediately.
  2. Tell them exactly which drug and dose — many are different medicines under one name.
  3. Do not give anything else and do not try home treatment for "calming".
  4. Serotonin syndrome is treatable but needs urgent hospital care — fluids, cooling and specific medicines.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

Sources & further reading

  • ASPCA Animal Poison Control — pet poison database & dosage references
  • Pet Poison Helpline — toxicology triage guidelines
  • Merck Veterinary Manual — toxicology monographs
  • Vets Now (UK) — emergency toxicosis guidance