Pictured: Imidazoline

Poisonous to: Cats, Dogs

Level of toxicity: Potentially severe or life-threatening

Common signs to watch for:

  • Vomiting
  • Lethargy or depression
  • Agitation
  • Incoordination
  • Hypotension
  • Life-threatening low heart rate

Imidazoline decongestants are topical vasoconstrictors (constricts blood vessels). Imidazolines (like oxymetazoline and tetrahydrozoline) are commonly found in over-the-counter eye drops and nasal sprays. When a bottle of product containing imidazolines is chewed, it can result in severe poisoning in pets – even death, when untreated. Even a small ingestion can cause clinical signs of vomiting, lethargy/depression or agitation, ataxia (incoordination), hypotension, and a life-threatening low heart rate.  Immediate veterinary attention should be sought following ingestion. Please contact your veterinarian or Pet Poison Helpline for life-saving advice if your pet has ingested one of these common eye drops or nasal sprays.

Poison type: medications

Alternate names: Oxymetazoline, tetrahydrozoline, naphazoline, nasal sprays, nasal decongestants, Afrin, ophthalmic preparation, Visine, eye drops