Final answer:
To determine the LD50 dosage for a 23 kg dog that has ingested theobromine, multiply the dog's weight by the LD50 of theobromine in dogs which is 255mg/kg. This yields a dosage of 5865 mg that could be lethal.
Step-by-step explanation:
The question involves calculating the LD50 of theobromine for a dog to determine when its owners should worry about the dog's well-being after ingesting chocolate. The LD50 for theobromine in dogs is 255mg/kg. Given that the dog in question weighs 23 kg, to estimate the potentially lethal dosage we multiply the dog's weight by the LD50 of theobromine.
LD50 Calculation: 23 kg × 255 mg/kg = 5865 mg
This means that ingestion of approximately 5865 mg of theobromine could be lethal for a dog weighting 23 kg. However, toxic effects can occur at much lower doses, so it is important for the dog to receive veterinary attention if there is suspicion of chocolate ingestion.