The Vomiting Dog and the Chocolate Bar

Chocolate contains methylxanthines - primarily theobromine and some caffeine. These are adenosine-receptor antagonists and phosphodiesterase inhibitors, producing CNS stimulation, tachycardia, and diuresis. Toxicity is dose-dependent and depends on:

• Chocolate type: cocoa content varies enormously - white chocolate (~negligible), milk chocolate (~2 mg/g theobromine), dark/semisweet (~5–10 mg/g), baking/unsweetened (~16–26 mg/g). 'Half a large bar' of dark chocolate is far more dangerous than the same mass of milk chocolate.
• Dog weight: the 14 kg dog has a smaller margin; the same bar that is trivial for a large dog can be toxic here.
• Time since ingestion: peak absorption is within a few hours; clinical signs in this dog at 90 minutes are consistent with ongoing absorption.

Rough clinical thresholds (theobromine, mg/kg): mild GI signs around 20 mg/kg; cardiac/CNS signs around 40–50 mg/kg; seizures and arrhythmias above ~60 mg/kg; potentially fatal above ~100–150 mg/kg. The dog's restlessness, vomiting, tachycardia, and hyperresponsiveness suggest it is in the mild-to-moderate range, but without the exact product we cannot be certain. The key message: dark chocolate and small dogs shift the risk sharply upward, and signs will likely peak over the next several hours.

Timing is decisive. At 90 minutes post-ingestion, the dog is already vomiting and is hyperresponsive/restless - both are relative contraindications to inducing emesis. Apomorphine in an already-vomiting, CNS-stimulated dog risks aspiration and excessive stimulation. Gastric lavage ('pumping') is not indicated in a stable, spontaneously vomiting dog; it is invasive, risks aspiration and arrhythmia provocation, and offers little benefit when the stomach is already emptying.

Appropriate plan:

• Do not induce further emesis - the dog is vomiting on its own and is neurologically stimulated.
• Activated charcoal is reasonable if the airway can be protected and the dog is not actively vomiting at the moment of administration; it adsorbs residual methylxanthines and may reduce absorption. Give with caution given the stimulation.
• Supportive care: IV fluids (crystalloids) to maintain perfusion and promote excretion; continuous ECG monitoring for arrhythmias; control hyperthermia; benzodiazepines for seizures/agitation if they occur.
• No specific antidote exists; management is decontamination plus symptomatic support.

Explain to the owner that 'pumping the stomach' is not the standard of care here and could cause harm; charcoal plus monitoring is the evidence-based approach.

Do not give theophylline or other methylxanthines. The dog is already intoxicated with methylxanthines (theobromine/caffeine); adding theophylline would be additive and could precipitate arrhythmias or seizures. The runny nose is likely hypersecretion from methylxanthine effects, not an indication for a respiratory stimulant.

Monitoring priorities (next 12 h):

• ECG - watch for tachycardia, premature ventricular complexes, and other arrhythmias; treat clinically significant arrhythmias (e.g., lidocaine for ventricular arrhythmias) rather than prophylactically.
• Temperature - hyperthermia from stimulation; cool if >40°C.
• Hydration/perfusion - IV fluids; monitor urine output (methylxanthines cause diuresis).
• Neurologic status - seizure threshold; keep environment quiet; have benzodiazepines ready.
• GI - ongoing vomiting; antiemetics if needed once decontamination is complete.

Prognosis: with supportive care, most dogs in the mild-to-moderate range recover over 24–72 hours as theobromine is slowly eliminated (half-life ~17 hours in dogs). Reassure the owner that absence of arrhythmia so far is favorable, but continued monitoring is essential because signs can progress.