Chocolate poisoning is caused by excessive intake of the methylxanthine alkaloids in chocolate, coffee, tea, and some over-the-counter stimulants. The poisoning affects many organ systems, and animals of all ages are susceptible. Poisoning is common in dogs because of their habit of rapid consumption, particularly puppies and young dogs as they may be more likely to ingest large amounts of unusual foods. Although dogs are the most susceptible, the toxin has been known to affect or kill cats, birds, rodents and reptiles as well.

What causes chocolate poisoning?

Methylxanthine alkaloids are naturally occurring drugs (primarily theobromine and caffeine) in chocolate, coffee, tea, and some over-the-counter medications. These drugs cause constricted blood vessels, rapid and weak heartbeat, and stimulate the nervous system.In most cases, dogs are poisoned by eating the processed chocolate used in sweets, chocolate bars and baking, since these contain high concentrations of theobromine and caffeine and dogs find them tasty. Chocolate preparations contain different concentrations of active compound. The biggest threat is from cooking chocolate, followed by semi-sweet chocolate, milk chocolate, and hot chocolate.

What are the signs of chocolate poisoning?

Vomiting and diarrhoea occur 2 to 4 hours after intake, and chocolate in the vomit may be obvious. Nervous system stimulation leads to hyperactivity, tremors, and seizures. The heart rate becomes increasingly rapid and irregular. Excessive urination may result from the diuretic (water clearing) action of the chocolate. Advanced signs include stiffness, excitement, seizures, and extreme response to noise, light, and touch. Heart failure, weakness, coma, and death can occur 12 to 36 hours after intake.

How is choclate poisoning diagnosed?

Chocolate poisoning can look similar to many poisonings or other conditions. Serious poisoning such as that caused by strychnine, amphetamines, pesticides, and some rodenticides can cause similar signs.If a combination of chocolate ingestion, vomiting, nervousness, or weakness is seen, take your dog immediately to your veterinarian. If possible, bring any vomit to the clinic as well, since this may aid in rapid identification of the toxic substance. Your veterinarian will need to examine your dog’s nervous system and cardiac function carefully. He may want to test the blood and urine concentration of sugar (glucose) and of the active ingredient in the chocolate. Since this poisoning progresses rapidly, signs may need to be treated symptomatically until a laboratory diagnosis is confirmed.

If your dog is having a seizure, do not attempt to cause vomiting; take him or her to your veterinarian without delay. If the chocolate has just been consumed ring your vet for advice immediately. There is no antidote for chocolate poisoning. Your veterinarian may use drugs to induce vomiting if the chocolate was consumed within the previous 2 – 4 hours or a stomach tube and fluids to clear the stomach of chocolate, followed by activated charcoal treatment to prevent any drug remaining from being absorbed. In dogs with advanced signs, specialized medications are needed to control the seizures and to correct the rapid and weak heartbeat in order to prevent heart failure.

What is the prognosis for chocolate poisoning?

The expected course of chocolate poisoning is 12 to 36 hours depending on the dosage and effectiveness of treatment. Prognosis is good if the chocolate is removed within 2 to 4 hours of ingestion. Prognosis is guarded in animals with advanced signs such as seizures and serious heart dysfunction.