Is Antidepressants (SSRIs/SNRIs) Toxic to Cats and Dogs?
Antidepressants (SSRIs/SNRIs) are severely toxic to cats and dogs — they can cause serotonin syndrome with tremors, seizures, and fever. Call a vet.
Potentially life-threatening — treat any exposure as an emergency.
Potentially life-threatening — treat any exposure as an emergency.
In an emergency, do not wait.
Medical disclaimer: This tool is for general information only and isnot a substitute for veterinary diagnosis or treatment. Toxicity depends on the amount, your pet’s size, and health history. If your pet may have ingested something harmful, contact your veterinarian or a poison control hotline ((888) 426-4435 / (855) 764-7661) immediately — do not wait for symptoms to appear.
What is Antidepressants (SSRIs/SNRIs)?
Antidepressants (SSRIs/SNRIs) are severely toxic to cats and dogs — they can cause serotonin syndrome with tremors, seizures, and fever. Call a vet.
Also known as: ssri, snri, fluoxetine, prozac, venlafaxine, effexor, sertraline, zoloft, citalopram.
Symptoms to Watch For
🐕 In Dogs
- Agitation, restlessness, and panting
- Tremors and muscle rigidity
- Rapid heart rate and dilated pupils
- Serotonin syndrome: tremors, seizures, high body temperature
🐈 In Cats
- Agitation and restlessness
- Tremors and dilated pupils
- Rapid heart rate and vocalization
- Serotonin syndrome with seizures and hyperthermia
What to Do If Ingested
- Call a veterinarian or poison hotline immediately.
- Note the medication name, mg strength, and number of pills, plus the time.
- Do not induce vomiting unless a vet directs it.
Steps apply to both cats and dogs. When in doubt, call a vet or poison hotline before acting.
When to Call the Vet Immediately
Call your veterinarian or a poison control hotline right away if you notice any of these:
- Any antidepressant was eaten
- Agitation, tremors, or a racing heart
- Dilated pupils or rigidity
- Seizures or a high body temperature
Frequently Asked Questions
Frequently Asked Questions
Which antidepressants are most dangerous to pets?
All SSRI and SNRI antidepressants (fluoxetine/Prozac, venlafaxine/Effexor, sertraline/Zoloft, citalopram, and others) can cause toxicity in pets. Venlafaxine (Effexor) is reported to be especially toxic to dogs. Even a dose or two can trigger serotonin syndrome — call a vet with the medication name and strength.
What is serotonin syndrome in pets?
Serotonin syndrome happens when too much serotonin builds up in the nervous system. Signs include agitation, tremors, muscle rigidity, dilated pupils, a rapid heart rate, high body temperature, and seizures. It can be life-threatening and needs immediate veterinary care.
What should I do if my pet ate my antidepressant?
Call a veterinarian or poison hotline immediately with the medication name, milligram strength, and number of pills eaten. Do not wait for symptoms — serotonin syndrome can develop quickly. Do not induce vomiting unless a vet tells you to.
Sources
This entry is reviewed against the following authoritative veterinary sources.
- Merck Veterinary Manual — Toxicology
- Pet Poison Helpline — Poisons
- America's Poison Centers — Annual Reports (NPDS)
Last reviewed: 2026-07-11