Chocolate is toxic to dogs but it is rarely fatal. Theobromide is the poisonous ingredient that is contained in chocolate. The severity of the symptoms depends upon the amount of theobromide in the chocolate and this varies depending upon the type of chocolate your dog ingests.
Theobromide is similar to caffeine and is used in medications for a variety of reasons: as a diuretic, as a heart stimulant, a blood vessel dilator and also as a smooth muscle relaxant. Toxicity is based on how many milligrams (mg) of theobromide your dog ingested and your dog’s weight in kilograms (kg) (mg/kg).
- >20mg/kg: vomiting, diarrhea, drooling, agitation and hyperactivity
- >40mg/kg: increased heart rate, high blood pressure, and abnormal heart rhythm
- >60mg/kg: tremors, twitching and seizures
- 200mg/kg: can be fatal
Darker and bitter chocolates contain more theobromide and therefore are more toxic to your dog. This is why not all chocolates are created equal:
- Baking chocolates: contain 130-450mg of theobromide/ounce
- Common milk chocolates: contain 44-58 mg of theobromide/ounce
- White chocolate: 0.25mg of theobromide/ounce
Example for a 50 pound dog: It would take 1 ounce of bakers chocolate or 8 ounces of mild chocolate to potentially show symptoms of chocolate poisoning.
There is an online chocolate toxicity meter that can help you determine the potential severity. Because it can take hours for your dog to start showing any signs of toxicity after ingestion of chocolate and these symptoms can last for days it’s important to always seek advice from your veterinarian or Pet Poison Hotline as soon as you suspect your dog has eaten chocolate.