Chocolate is toxic to dogs because it contains theobromine and caffeine, which dogs process slowly. Dark chocolate is most dangerous, so call a vet if your dog eats some.
Why
Chocolate contains theobromine and caffeine. Dogs break down theobromine very slowly, so it builds up.
Toxicity
Dark chocolate and baking chocolate are worst. Toxic doses start at about 20 mg per kg of body weight (theobromine). Severe signs appear at 40 to 60 mg/kg.
Signs
Vomiting, diarrhea, restlessness, fast heartbeat, seizures.
What to do
Call a vet or the ASPCA Poison Control Center at (888) 426-4435.
Not just chocolate
Coffee, tea and cocoa mulch are risks.
Theobromine
Chocolate contains theobromine and caffeine, both methylxanthines. Dogs metabolize theobromine very slowly, so it builds up in the blood and can last 17.5 hours half life, compared with about 6 to 10 hours in humans. It causes effects on the heart, nervous system and kidneys.
Amounts that cause problems
Theobromine content varies:
- White chocolate: negligible (about 0.25 milligrams per ounce).
- Milk chocolate: about 64 milligrams per ounce.
- Dark chocolate: about 150 milligrams per ounce.
- Baking chocolate: about 390 milligrams per ounce.
- Cocoa powder: about 800 milligrams per ounce.
Signs of toxicity can begin at about 20 milligrams per kilogram of body weight, and severe signs at 40 to 60 milligrams per kilogram. Seizures can occur above 60 milligrams per kilogram.
Signs
Vomiting, diarrhea, restlessness, increased thirst, panting, fast heart rate, tremors, seizures and, in severe cases, collapse. Signs begin within 6 to 12 hours and can last 72 hours.
What to do
Call your veterinarian, the ASPCA Animal Poison Control Center (888-426-4435) or the Pet Poison Helpline (855-764-7661) right away. They will ask the type and amount of chocolate and the dog’s weight. Treatment may include inducing vomiting (only under veterinary instruction), activated charcoal, IV fluids and medications.
Other dangers
Grapes and raisins, xylitol (sugar substitute), macadamia nuts, onions, garlic, alcohol and avocado can be harmful.
Prevention
Keep chocolate, cocoa mulch and baked goods out of reach, especially at Halloween, Christmas, Valentine’s Day and Easter.
Prognosis
Prompt treatment leads to a good outcome in most cases.
Toxic dose
Chocolate contains theobromine and caffeine, which dogs metabolize slowly. Toxic effects can appear at around 20 mg of theobromine per kilogram of body weight, and severe signs at 40 to 60 mg/kg or more. Baking chocolate and dark chocolate contain much more theobromine than milk chocolate: unsweetened baking chocolate has about 390 mg per ounce, dark about 150 mg per ounce and milk about 60 mg per ounce.
What to do
Signs include vomiting, diarrhea, restlessness, fast heartbeat, tremors and seizures, usually starting within 6 to 12 hours. Call a vet or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately; do not wait for symptoms. Treatment may include induced vomiting by a vet, activated charcoal, IV fluids and heart monitoring.
Based on data from the ASPCA Animal Poison Control Center and the Merck Veterinary Manual
