Alternate names

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

Toxicity to pets

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.

Common signs to watch for:

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



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The content of this page is not veterinary advice. A number of factors (amount of substance ingested, size of the animal, allergies, etc.) determine what is toxic to a particular pet. If you think your pet has eaten something potentially toxic, call Pet Poison Helpline or seek immediate veterinary treatment.