One of the most common toxicities in dogs is caused by chocolate ingestion. Dogs cannot metabolize chocolate in the same way people can, so keeping chocolate or products containing caffeine in a secure location out of your dog’s reach is essential. The amount ingested that can cause toxicity depends on the size of the dog and the type of chocolate, with darker and more bitter chocolates being the most toxic. If your dog accidentally ingests chocolate, contact an emergency veterinarian immediately.

Cause

Two toxic components to dogs found in chocolate are caffeine and theobromine, which predominately cause stimulation of the central nervous system and heart. They also act as diuretics, which can quickly lead to dehydration. Dogs may also be at risk for developing gastrointestinal distress or even pancreatitis because many chocolate products are high in fat and sugar.

The amount of theobromine and caffeine in a chocolate product varies, but generally, the darker the chocolate, the higher the risk to dogs. The potential for toxicity is highest in cocoa powder, followed by unsweetened (baker’s) chocolate, semisweet and sweet dark chocolate, milk chocolate and cocoa bean hulls. For example, one ounce of milk chocolate per pound of a dog’s body weight can be deadly compared to unsweetened baking chocolate, where as little as 0.1 ounces per pound of a dog’s body weight may be lethal. For this reason, even ingesting small amounts, especially in a smaller dog, should be treated as an emergency.

Clinical Signs

The clinical signs seen vary based on the amount of chocolate ingested and the dog's size but may occur within 2-12 hours after ingestion. Clinical signs can last 12-36 hours, sometimes longer in severe toxicities. The signs of chocolate toxicity may include the following:

• Vomiting
• Diarrhea
• Increased thirst and urination
• Restlessness
• Fast breathing
• Increased heart rate or irregular heart rhythm
• Hyperexcitability
• Tremors
• Incoordination
• Seizures
• Fever
• Coma

Diagnosis

Dogs are most commonly diagnosed with chocolate toxicity after a history of known ingestion and physical exam findings. It is helpful if you know the amount and type of chocolate your dog consumed to help determine their overall risk. Your veterinarian may recommend blood work or additional testing depending on their clinical signs.

Treatment

Treatment for chocolate toxicity depends on the clinical signs displayed by the animal. If a patient has life-threatening clinical signs, those will be managed first. Otherwise, treatment involves decontamination with medication to induce vomiting, even if it has been a few hours after ingestion, since chocolate tends to absorb slowly. Most patients require hospitalization.

Treatment for chocolate toxicity may include any of the following:

• Induced vomiting
• Administering oral activated charcoal
• Antinausea medications and GI protectants
• IV fluids
• Medications to stop tremors
• Medications to prevent irregular heart rhythms
• Medication to stop seizures
• Urinary catheterization or frequent walking to encourage urination

Outcome

The outcome of chocolate toxicity depends on the amount and type ingested, the dog’s weight and how promptly treatment was initiated. Delaying treatment from the time a dog eats chocolate can worsen the associated clinical signs and prognosis. Darker and more bitter chocolates are more toxic to dogs, but all forms of chocolate carry some risks. Dogs with mild signs or those that ingested small amounts generally have a good prognosis with prompt treatment. The prognosis is less favorable for dogs with severe clinical signs like seizures or collapse.