My dog chewed a battery — what do I do?
✓ Reviewed against PDSA, Blue Cross & Animal PoisonLine guidance · Last updated: 2026-07-05
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Why batteries are so dangerous
Batteries are one of the most chemically damaging foreign body ingestions in dogs. The contents vary by type: alkaline batteries (AA, AAA, C, D, 9V) contain potassium hydroxide, a highly caustic alkali. Button batteries (coin cells) contain lithium or zinc. Lead-acid batteries (car batteries) contain concentrated sulfuric acid. All cause severe chemical burns on contact with mouth, oesophageal, and stomach tissue.
Button batteries (coin cells) used in remote controls, key fobs, hearing aids, and toys carry the highest risk of any battery type. If swallowed, they can lodge in the oesophagus and generate an electrical current that causes deep necrotic burns through the tissue within 2 hours — even when the battery hasn't leaked. This is a different mechanism from chemical burns but equally catastrophic. Perforation of the oesophagus is a surgical emergency with poor prognosis if delayed.
Even if your dog only chewed the battery and it appears intact, the metal casing may have micro-cracks allowing electrolyte fluid to contact the gums and tongue. Burns are not always immediately visible — the damage may appear hours later.
What to do right now
- Call your vet or ASPCA Poison Control (888) 426-4435 immediately — don't wait to see if symptoms develop
- If there is visible battery fluid in or around the mouth: rinse gently with water for 15–20 minutes
- Do NOT induce vomiting — vomiting brings caustic material back through the oesophagus and compounds the burns
- Do NOT give milk, bread, or any home remedy — these are not protective and delay treatment
- Bring the battery packaging if you have it — your vet needs to know the battery type and size
- If a button battery was swallowed: this is an emergency X-ray situation — location determines treatment urgency
Signs of battery burns
- Drooling excessively
- Pawing at the mouth
- Red or ulcerated tissue in the mouth
- Difficulty swallowing or refusing food
- Vomiting (especially if retching repeatedly)
- Lethargy, crying, or signs of pain
- Note: burns may not be visible immediately
Battery types and risk levels
Button/coin batteries — highest risk, especially if swallowed. Electrical burns + chemical burns. Emergency X-ray required. AA/AAA/C/D alkaline — high risk if chewed through; caustic potassium hydroxide burns. 9V batteries — higher voltage, can arc and burn before leaking. Lithium batteries (slimline rectangles in laptops/phones) — thermal risk in addition to chemical. Car batteries — rarely chewed but contain concentrated sulfuric acid; extreme emergency.
Prevention
- Store batteries in drawers or containers out of dog reach
- Battery-powered toys with accessible battery compartments are a risk — secure or remove
- Check that remote controls have tight battery covers (dogs chew remotes frequently)
- Dispose of dead batteries immediately — do not leave on surfaces
Preventing battery access at home
Button/coin batteries are the highest-risk type and are commonly found in remote controls, key fobs, hearing aids, and children's toys — store spares in a sealed container out of reach, and check that battery compartments in household devices are properly screwed shut, since dogs can pop open battery doors that rely on a simple sliding catch. Dispose of used batteries immediately rather than leaving them in an open bin.
Does size or breed matter?
Small dogs and puppies are at higher risk simply because they're more likely to explore and chew small objects, and a battery is proportionally a bigger hazard relative to a smaller oesophagus and gut. Any dog of any size that has swallowed a button battery needs an urgent vet visit — this is one of the few genuinely time-critical scenarios on this site, as the battery can cause chemical burns within hours.