Chocolate toxicity

A few notes from Dr Grafinger:

Chocolate toxicity usually occurs during the holidays (Halloween, Thanksgiving, Christmas and Easter) when pets are exposed or fed a variety of chocolate containing products. It is among the 20 most common toxicities which occur in veterinary medicine. The toxicity occurs more commonly in dogs and almost never in our feline companions. Cats are more particular about what they eat. Dogs tend to consume large quantities of unusual foods quickly.

Common products containing cocoa include: candy, cakes, cookies, brownies, baking supplies, and cocoa bean mulches.

In general the lighter colored chocolate products (e.g. White chocolate) are less toxic, and darker products are more toxic (e.g. Hershey’s Special Dark Chocolate). The toxic compounds in chocolate are methylxanthine alkaloids which include caffeine and theobromine. White chocolate contains 0.05 g/kg of theobromine, and baking chocolate contains 16 g/kg theobromine. Many chocolate products have a high fat content which can precipitate pancreatitis as well.

Toxic doses according to ASPCA Animal Control Center are as follows:
Mild signs occur in dogs ingesting 20 mg/kg.
Severe signs are seen with ingestion of 40-50 mg/kg
Seizures can occur with a dose of 60mg/kg
Death can occur with 100-200 mg/kg