Everybody loves chocolate and so it comes as no surprise when Lassie goes for a chocolate fix. If your dog ate your last batch of brownies or stole your unattended bag of Oreo cookies, you have reason to be concerned, as chocolate can be harmful to dogs.

The culprit of such intolerance is a substance found in chocolate called "Theobromine". The level of chocolate toxicity in dogs is determined by various factors: the amount ingested, the concentration of theobromine, the over all health status of the dog and the size and weight of the dog. The effects may range from a mild stomach upset, excitability, to even a potentially fatal cardiac arrest.  But how much is too much? How can an owner know when it is time to rush their beloved dog to the vet or simply keep a watchful eye on him/her?As a general rule of thumb, the toxic levels of chocolate in dogs according to petplace.com are as follows:

White chocolate 45 ounces to 90 ounces per pound of body weight. A 20 pound dog would need to ingest 55 pounds to exhibit nervous system signs.

Milk chocolate 0.7 ounces to 2 ounces per pound of body weight. A 20 pound dog would have to ingest a little less than one pound to exhibit nervous system signs.

Semi-sweet chocolate 1/3 ounce to 1 ounce per body weight. A 20 pound dog would have to ingest 6 ounces to exhibit nervous system signs.

Baking chocolate 0.1 ounce to 0.3 ounces per body weight. A 20 pound dog would have to ingest 2 ounces to exhibit nervous system signs. All it takes for a 10 pound dog is one ounce.

So what to do once your realize your dog has ingested a toxic dose? The best thing to do is to contact your veterinarian and follow his instructions. He/she will need to know the amount of chocolate ingested, how long ago it was ingested and the weight of your dog. He/she may ask you to induce vomiting if your dog ingested the chocolate less than 2 hours ago. This is the time when the chocolate is still in the stomach.

Always keep on hand 3% hydrogen peroxide which will help induce vomiting. Your vet will tell you much to give to induce vomiting. Unfortunately, vomiting alone, may not be sufficient, since some of he theobromine may still be absorbed. Your dog may require further treatment at the vet's hospital.

Symptoms suggesting chocolate toxicity include:

Vomiting

Diarrhea

Hyperactivity

Panting

Increased urination

High blood pressure

High heart rate

Seizures

Coma

Always keep chocolate and candy bars away from your furry friend. Always keep on hand 3% hydrogen peroxide and activated charcoal. Very likely, the quicker you act the better the prognosis. Generally, dogs treated within 4 hours have the highest chances of survival should they have ingested a toxic dose. Time is of the essence therefore, do not delay treatment, rather call your vet for advice and follow it carefully.