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My 4 kg cat licked his ear infection drops that were left uncapped overnight — is the spoiled medication more dangerous?

Cats · Emergency guide

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

Yes, call your vet right away. While the main risk is the medication itself, leaving it uncapped can introduce bacteria or degrade the formula, but the active ingredients like gentamicin remain toxic. Licking it means he ingested it orally, which can cause vomiting or diarrhea. More seriously, an overdose can lead to hearing loss or kidney damage. Do not put anything more in his ear, and bring the bottle with you to the clinic so they know exactly what he got into.

Why Ear Medications Can Be Harmful

Ear medications often contain antibiotics (like gentamicin), antifungals, and corticosteroids. If ingested orally, they can cause gastrointestinal upset.

More seriously, an overdose applied directly into the ear can be absorbed systemically or cause local toxicity to the ear structures.

Aminoglycoside antibiotics (e.g., gentamicin) can cause irreversible hearing loss and kidney damage if overdosed.

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

  • Head tilting or shaking
  • Loss of balance and coordination
  • Vomiting and diarrhea
  • Loss of appetite
  • Redness or pain in the ear
  • Signs of hearing loss (not responding to sounds)

What to do right now

  1. Call your veterinarian immediately.
  2. Do NOT put anything more into the ear unless instructed by your vet.
  3. If the medication was ingested, do NOT induce vomiting unless specifically told to do so.
  4. Your vet will examine the ear and may flush it. Supportive care for systemic symptoms may be needed.
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 Ear Infection Medication Overdose emergency guide.

Open the full emergency guide: Ear Infection Medication Overdose →