Why Chocolate is Toxic to Dogs

dynamic, chocolate, nutrition, poison, toxin - By Staff Writer on Tuesday, January 26, 2010 - 10:07

It is a common known fact that chocolate is poisonous to dogs, but most owners do not know why or how much can be lethal.  Many owners think that chocolate cause harm to dogs only in large doses, when in fact any amount of chocolate should be avoided, as each dog’s reaction will vary.  

Chocolate contains a chemical called theobromine or xantheoses that comes from the cacao plant.  Theobromine can be found in other sources like the cola nut or acai berries but the most common source around the house is chocolate.  Theobromine is like caffeine in that it is a stimulant that increases heartbeat and dilates blood vessels and is a diuretic.   While humans can digest it safely, dogs metabolize it at a much slower rate causing accumulation of the chemical in their system that can lead to theobromine poisoning.

Once the chemical is ingested it begins to metabolize and can cause hyper activity, increased heart rate, aggression, increased urination, muscle twitches, vomiting and diarrhea.  The chemical can cause damage to the heart, central nervous system and kidneys, which can lead to death.

On average a lethal dose of theobromine is around 100mg to 200mg per kg of bodyweight, therefore the amount your dog can ingest safely depends greatly on size and age of your dog and the type of chocolate he ingested.  Smaller dogs will be more susceptible to the effects of the chemical then larger dogs and older dogs or puppies will be at greater danger of poisoning then fully developed healthy adult dogs.  The type of chocolate will determine the concentration of theobromine giving it its toxicity levels.  White chocolate is the least toxic because it is the most diluted whereas baker’s chocolate is the most concentrated and lethal.  Listed below are rough estimates of toxicity levels:

· White chocolate: 200 ounces per pound of body weight. It takes 250 pounds of white chocolate to cause signs of poisoning in a 20-pound dog, 125 pounds for a 10-pound dog.

· Milk chocolate: 1 ounce per pound of body weight. Approximately one pound of milk chocolate is poisonous to a 20-pound dog; one-half pound for a 10-pound dog. The average chocolate bar contains 2 to 3 ounces of milk chocolate. It would take 2-3 candy bars to poison a 10-pound dog. Semi-sweet chocolate has a similar toxic level.

· Sweet cocoa: 0.3 ounces per pound of body weight. One-third of a pound of sweet cocoa is toxic to a 20-pound dog; 1/6 pound for a 10-pound dog.

· Baking chocolate: 0.1 ounce per pound body weight. Two one-ounce squares of bakers' chocolate is toxic to a 20-pound dog; one ounce for a 10-pound dog.

Early Signs Your Dog Has Eaten Chocolate

· Chewed wrappers is the most tell tale sign
· Vomiting
· Diarrhea
· Excessive thirst
· Twitching and restlessness

If you suspect your dog has eaten any amount of chocolate it is best to play it safe and take him to the vet to get his stomach pumped.  The toxin will last approximately 18 hours in your dog’s system and your vet needs to induce vomiting quickly to remove as much of it from his stomach as possible, preventing the accumulation of the poison.  Your vet will then treat your dog’s symptoms through fluids, oxygen, and medication to prevent dehydration and any other symptoms that should they arise.  Avoiding consumption is always the best step but should something happen and your dog does ingest it, only your vet will be able to help.