Chocolate toxicosis in pets

Chocolate ingestion is very common in pets, particularly dogs, but has also been reported in other animals including cats and rabbits. Most cases occur around Christmas and Easter, when large amounts of chocolate are often present in the home in the form of chocolate bars, snacks, confectionery, Easter eggs and chocolate figurines. Chocolate-covered raisins, nuts and coffee beans present an additional toxicological hazard in dogs. The type of chocolate is defined in law by the percentage of cocoa solids, with dark (plain) chocolate containing more than milk chocolate. The main toxic component of chocolate is theobromine, a methylxanthine, although caffeine, another methylxanthine, is also present. These cause central nervous system stimulation with cardiac and respiratory hyperactivity. Signs include gastrointestinal effects, excitability, hyperactivity, tachycardia, tremors, hypertension and hyperthermia. Signs of toxicosis generally occur within a few hours of ingestion. The mainstays of treatment are decontamination and supportive care with rehydration, control of central nervous system stimulation and arrhythmias as required. Most pets recover fully, and death is uncommon; however, prognosis is more guarded in pets with seizures or arrhythmias.