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.
Signs to watch for
- Restlessness, agitation, pacing
- Tremors or shaking, muscle twitching
- Very high body temperature, panting
- Vomiting, diarrhoea
- Seizures, severe rigidity (emergency)
What to do right now
- Call your vet or poison control immediately.
- Tell them exactly which drug and dose — many are different medicines under one name.
- Do not give anything else and do not try home treatment for "calming".
- 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.
The step-by-step response, from the first minute to the vet visit, is in our Antidepressant (SSRI) Poisoning emergency guide.