TL;DR: Battery ingestion is a high-urgency medical emergency that can cause severe internal chemical burns or electrical tissue damage within hours. Contact a veterinarian immediately, even if your dog appears to be acting normally.
What happens if my dog swallows a battery?
Battery ingestion occurs when a dog swallows any type of battery, such as alkaline (AA, AAA), lithium, or small button batteries. These items are extremely hazardous because they contain corrosive chemicals and heavy metals. When the battery comes into contact with saliva or gastrointestinal fluids, it can leak toxic substances or create an electric current that damages the surrounding tissue.
Is it an emergency if my dog eats a battery?
- This is a High Urgency Emergency; you must contact a veterinarian or an emergency pet clinic immediately.
- Lithium button batteries are especially dangerous because they can generate an electrical circuit in the esophagus, causing life-threatening tissue necrosis and perforation in as little as two hours.
- Even if your dog seems fine, internal chemical burns can occur rapidly and silently.
Why should I take a photo of the battery or packaging for triage?
- If you have the packaging or a matching spare battery, take a clear photo of it to help the veterinary team identify the size, voltage, and chemical composition.
- Knowing the exact type of battery allows the vet to assess the risk of leakage or electrical burns.
- Information from the photo helps determine whether the battery needs to be removed via endoscopy or surgery versus being monitored as it passes.
Clinical Context (Merck Veterinary Manual)
Ingestion of alkaline batteries poses a risk of gastrointestinal tract corrosive injury and foreign body obstruction; dogs are most commonly involved. The alkaline gel in batteries causes liquefactive necrosis of tissues on contact, resulting in burns that can penetrate deeply into tissue. Lithium disk batteries may lodge in the esophagus and generate a current against the esophageal walls, resulting in circular ulcers that have the potential to be perforating. If a battery is swallowed intact without chewing, induction of emesis may result in expulsion, but emesis should not be induced if there is any possibility that the battery casing has been punctured due to the risk of leakage of alkaline gel onto oral and esophageal mucosa. When disk batteries have been ingested, 20 mL boluses of tap water every 15 minutes will decrease the severity and delay the development of current-induced esophageal ulceration. Radiographs may help confirm the diagnosis and location of the battery, but some disk batteries do not show up well. Batteries that do not pass through the pylorus within 48 hours of ingestion are unlikely to pass on their own and may require surgical or endoscopic removal; endoscopic removal is not recommended if the battery casing has been punctured. Batteries that have obviously been punctured should be removed surgically to prevent gastric or intestinal ulceration. Serial radiography to verify battery location is recommended until the battery is expelled, and adding bulk to the diet and judicious use of cathartics may facilitate passage of batteries that have passed through the pylorus.
Chapter: Toxicology, Gastroenterology, Surgery
Source: The Merck Veterinary Manual, 11th Edition (Page 3003)