Why is this dangerous?
Alkaline batteries leak potassium hydroxide, a strong caustic that burns the mouth, oesophagus and stomach. Button cells are the worst: in a wet, salty tract they generate an electric current that causes deep liquefaction burns within two hours.
Lithium batteries add heavy-metal toxicity and can cause severe tissue necrosis.
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
- Drooling, pawing at the mouth, refusing food
- Vomiting, sometimes with blood
- Abdominal pain, restlessness, pacing
- Dark or black stools (gut bleeding)
- Lethargy, collapse, fever if the battery has been in place for hours
What to do right now
- Go to the vet immediately — do not wait for symptoms. Burns progress while the battery sits in the tract.
- Do not induce vomiting and do not give food or water; the battery may still be in the oesophagus.
- Tell the vet the size and type of battery (button, AA, lithium).
- X-rays decide next steps: endoscopy to remove it, or surgery if it has already passed into the bowel.
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 Batteries (Alkaline, Lithium, Button) emergency guide.