How Much Chocolate Does It Take To Make A Dog Sick?

Chocolate is toxic for dogs and if your dog eats chocolate, before consulting Dr. Google, it is best to try to determine how much your dog ate and call the Pet Poison Helpline or your vet.  Since each dog is different, and each type of chocolate contains different levels of methylxanthines (caffeine and theobromine), the dangerous substances in chocolate, you need to determine if your dog has eaten enough to risk its life or become very sick.

Dogs are unable to break down theobromine the way people can.  In humans, theobromine is used as a diuretic, heart stimulant, muscle relaxer and blood vessel dilator, so it’s easy to see why the substance is harmful for dogs.

How Much Chocolate Does It Take to Make a Dog Sick?

When it comes to chocolate toxicity in dogs, the darker the chocolate, the higher the level of methylxanthines.  Dark natural cocoa, raw cocoa powder, baking chocolate, and dark chocolate candy all contain far more caffeine and theobromine than milk chocolate.  However, if your dog has eaten certain amounts of milk chocolate, you could also have an emergency.

For example, a 50-pound dog may be sickened by one ounce of dark chocolate or 8 ounces of milk chocolate.

According to The Hershey Company, 1.55 ounces of Hershey’s milk chocolate contains 64 mg of theobromine while 1.45 ounces of Hershey’s Special Dark Chocolate contains 176 mg of theobromine-more than double the amount.

The amount of theobromine can also vary due to the growing conditions of the cocoa beans.

The Symptoms of Chocolate Poisoning in Dogs:

If your dog has any of the signs of chocolate poisoning, you should seek immediate medical care.  Signs can develop quickly and last for several days. The faster your dog receives medical care, the better the prognosis for your pet.

The symptoms of chocolate toxicity in dogs include:

  • Vomiting and diarrhea
  • Drooling
  • Lethargy
  • Racing heart
  • Tremors
  • Twitching
  • Increase in body temperature
  • Rapid breathing
  • Seizures
  • Low blood pressure
  • Rigid, stiff muscles
  • Heart failure
  • Weakness
  • Coma

Theobromine measurements (approximate): 

  • Milk chocolate 60 mg/oz
  • Baking chocolate 450 mg/oz
  • Semi-sweet chocolate 260 mg/oz
  • Hot chocolate 12 mg/oz
  • White chocolate 1 mg/oz

Type of Chocolate - Theobromine oz/Caffeine oz 

  • White chocolate 0.25/0.85
  • Milk chocolate 58/6
  • Dark, sweet chocolate 130/20
  • Semi-sweet chocolate chips 138/22
  • Baker’s (unsweetened) chocolate 393/ 47
  • Dry cocoa powder 737/70
  • Instant cocoa powder 136/15
  • Cocoa beans 600/Not available
  • Coffee beans 600/Cocoa bean hulls 255 

When you call your vet, try to determine how much chocolate your dog has eaten (always assume the worst-case scenario), type of chocolate, and weight of your dog.

According to the ASPCA:

“As as little as 4 ounces of milk chocolate—or only 0.5 oz of baking chocolate—can cause serious problems in a 10-pound dog. While white chocolate may not have the same potential as darker forms to cause a methylxanthine poisoning, the high fat content of lighter chocolates could still lead to vomiting and diarrhea, as well as the possible development of life-threatening pancreatitis, an inflammatory condition of the pancreas.

Based on ASPCA Animal Poison Control Center (APCC) experience, mild signs occur in animals ingesting 20 mg/kg of theobromine and caffeine, severe signs are seen at 40-50 mg/kg, and seizures occur at 60 mg/kg (ASPCA/APCC Database: Unpublished data).

Accordingly, less than 1 oz of milk chocolate/lb (2 oz/kg) is potentially lethal to dogs; for baking (unsweetened) chocolate, less than 0.1 oz/lb (0.2 ounces/kg) is potentially lethal. Methylxanthines can cross the placenta and pass into the milk, so unborn or nursing offspring can be affected by chocolate toxicosis in the dam. Clinical signs usually occur within six to 12 hours of ingestion. Initial signs include polydypsia, vomiting, diarrhea, bloating, and restlessness. Signs progress to hyperactivity, polyuria, ataxia, tremors, and seizures. Other effects include tachycardia, premature ventricular contractions, tachypnea, cyanosis, hypertension, hyperthermia, and coma.  Less commonly, bradycardia and hypotension may occur.  Hypokalemia is possible late in the course of the toxicosis. Because of the high fat content of many chocolate products, pancreatitis is a potential consequence 24 to 72 hours after ingestion. Death is generally due to cardiac arrhythmias or respiratory failure.”

Sugar Free Chocolate is Deadly

If your dog eats sugar free chocolate sweetened with xylitol, this is always an emergency. Xylitol is so toxic to pets that The ASPCA Poison Control center recommends that candy or other products containing xylitol be kept out of households with dogs.  Given this, if your dog does eat sugar free chocolate, you should seek medical care right away and hope the wrapper was not consumed along with the candy as well and request any houseguests keep all sugar free products far away from your dog.