|What it's in: When it comes to chocolate, dark equals dangerous. That’s because the darker the chocolate, the larger the amount of theobromine—a cousin chemical to caffeine—it contains. Thus, baker’s chocolate, semi-sweet chocolate, cocoa powder, and gourmet dark chocolates are more toxic than milk chocolate. White chocolate has very little theobromine and will not cause poisoning in pets.
Threat to pets: The dose ingested determines the danger. Pets that ingest a few M&Ms or a bite of a chocolate chip cookie are unlikely to develop chocolate poisoning.
For milk chocolate, any ingestion of more than 0.5 ounces per pound of body weight may put dogs and cats at risk. Ingestions of more than 0.13 ounces per pound of body weight of dark or semi-sweet chocolate may cause poisoning. Almost all ingestions of baker’s chocolate can result in poisoning and are considered emergencies.
Very young pets, geriatric pets, and animals with underlying disease are at a higher risk for poisoning than healthy, adult dogs and cats. Due to the large amount of fat in chocolate, some pets may develop pancreatitis (inflammation of the pancreas) after eating chocolate or baked goods containing chocolate (see fatty foods).
Signs: Small amounts of chocolate may cause mild vomiting and diarrhea. Larger amounts can cause severe agitation, tachycardia (elevated heart rate), abnormal heart rhythms, tremors, seizures, and collapse.
Treatment: Induce vomiting and then administer multiple doses of activated charcoal to decontaminate (adsorb and remove toxins). Administer aggressive intravenous fluids to help with excretion, sedatives to calm the pet, specific heart medications to reduce heart rate and blood pressure, anti- convulsants for seizures, and antacids for stomach discomfort and diarrhea. Theobromine may be reabsorbed across the bladder wall so a urinary catheter or frequent walks are needed to keep the bladder empty.
Prognosis: Excellent in pets with mild signs, such as mild stomach upset or slight restlessness. Poor in those with severe signs, such as collapsing and seizures.