Toxic to cats · Medications

Are Antihistamines toxic to cats?

Extreme severity

Yes, Antihistamines are extremely toxic to cats. Even a small amount can be life-threatening, so treat any exposure as an emergency and contact a vet immediately.

Symptoms to watch for

  • Agitation
  • Lethargy
  • Sedation
  • Aggression
  • Abnormal heart rate
  • Abnormal blood pressure
  • Vomiting
  • Diarrhea
  • Inappetance
  • Seizures
  • Respiratory depression
  • Death

How vets treat it

Contact a veterinarian or Pet Poison Helpline immediately for life-saving treatment recommendations.

Why it's dangerous

Antihistamines affect the central nervous system and cardiovascular system, leading to a range of symptoms from sedation to severe agitation and respiratory depression.

Toxic compound: diphenhydramine

Good to know

Commonly used in both human and veterinary medicine for allergies and skin disease; accidental ingestion can be fatal.

Sources

This page is informational and is not veterinary advice. If your pet has been exposed to something risky, contact your vet or an animal poison control line right away.

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