What happens if a rat eats chocolate? - briefly
Chocolate’s theobromine is poisonous to rats, leading to vomiting, hyperactivity, seizures, and possible fatal cardiac arrest; even modest portions can cause severe toxicity.
What happens if a rat eats chocolate? - in detail
Rats that ingest chocolate are exposed to theobromine, a methylxanthine that rodents metabolize far more slowly than humans. Blood concentrations rise rapidly after consumption, reaching toxic levels at doses of approximately 100 mg kg⁻¹ for theobromine alone; chocolate typically contains 1–5 mg g⁻¹, so a 250‑g rat would experience toxicity after eating roughly 5–10 g of milk chocolate or 1–2 g of dark chocolate.
Theobromine acts as a non‑selective phosphodiesterase inhibitor, increases cyclic AMP, and antagonizes adenosine receptors. In the cardiovascular system this produces tachycardia and vasodilation, while the central nervous system shows heightened excitability, leading to restlessness, tremors, and seizures. Peripheral effects include diuresis and gastrointestinal irritation, often manifested as vomiting or diarrhea.
Typical clinical signs appear within 30 minutes to 2 hours post‑exposure:
- Rapid breathing and increased heart rate
- Hyperactivity followed by muscle twitching
- Convulsive episodes
- Excessive urination and possible dehydration
- Abdominal cramping and loose stools
If the dose exceeds the lethal threshold (≈200 mg kg⁻¹ of theobromine), fatal outcomes result from cardiac arrhythmias, severe electrolyte imbalance, and respiratory failure. Laboratory analysis of affected rats shows elevated plasma theobromine, high creatinine, and metabolic acidosis.
Management strategies focus on immediate decontamination and supportive care:
- Induce emesis or perform gastric lavage within the first hour.
- Administer activated charcoal to bind residual toxin.
- Provide intravenous fluids to correct dehydration and electrolyte loss.
- Use anti‑convulsant drugs (e.g., diazepam) for seizure control.
- Monitor cardiac rhythm continuously; apply anti‑arrhythmic agents if needed.
Preventive measures include storing chocolate products away from rodent habitats, using bait stations that contain no methylxanthines, and monitoring laboratory colonies for accidental exposure.