With more and more battery powered gadgets in our homes, battery ingestion is becoming a bigger and bigger problem. The family comes home to find their remote control chewed into several pieces, the battery is missing. Unfortunately, batteries are very dangerous. Alkaline dry cell batteries ( 9-volts, D, C, AA, etc) and button or disc batteries contain hazardous chemicals that can destroy tissue. The chemical causes severe ulcers. If a dog punctures the battery and then swallows it, they usually sustain severe damage to the mouth, esophagus and stomach. I often find a black powdery material on the lips and in the mouth of these patients.
The goal of treatment is to remove the battery as quickly as possible with either an endoscope or during surgery. DO NOT INDUCE VOMITING! When the battery is vomited back up, more damage will occur. If you think your pet may have eaten a battery, seek veterinary care immediately. In my experience, quick action is critical for this type of toxicity.
Source:
Lee, Justine. Tope Ten Small Animal Toxins: Recognition, Diagnosis, Treatment. ACVIM 2010.