My Billings Gazette

Although chocolate toxicosis is more common in dogs, the toxin has been known to affect or kill cats, birds, rodents and reptiles as well.

Keep candy and baked goods out of pets' reach, do not let pets in the kitchen unsupervised while baking, and never feed a dog milk chocolate as a treat because the dog may develop a taste for it and subsequently seek it out.

Chocolate contains theobromine and caffeine, which are both methylxanthines. The amount of methylxanthines present depends on the type of chocolate (see table). In general, the less sweet it is, the more toxic it could be. Unsweetened baking chocolate contains almost seven times more theobromine than milk chocolate, which is why a dog can eat an occasional piece of milk chocolate and not show clinical signs. The theobromine in chocolate-coated candy is more dilute than that in solid chocolate bars.

The following table is a common example of toxicity for a 60 lb. dog, for a more detailed table with several variations in amounts and weights, see here.

The toxicity depends on the type of chocolate, the amount ingested, the size of the animal, and the animal's sensitivity to methylxanthines.  Clinical signs of chocolate toxicosis include vomiting, diarrhea, hyperactivity (including restlessness, agitation, and pacing), polyuria, polydipsia, lethargy, tachycardia, cardiac arrhythmias, tremors and seizures, and death. Some of these signs can be seen with the ingestion of as little as 0.25 oz of baking chocolate by a 10-lb dog. Based on Animal Poison Control Center experience, mild signs occur in animals ingesting 20 mg/kg and severe signs are seen at doses over 40 mg/kg. The half-life of chocolate in the dog is 17.5 hours.

Treatment for chocolate toxicosis involves:

• Stabilizing the pet; treating life-threatening cardiovascular and respiratory abnormalities and controlling seizures.
• Using standard gastrointestinal decontamination procedures: emesis, repeated dosing with activated charcoal, and a cathartic.
• Administering fluids to help eliminate methylxanthines. A urinary catheter is recommended to prevent reabsorption of caffeine by the bladder wall.
• Providing supportive care until complete recovery (sometimes for up to 72 hours).

Also beware of Xylitol

Xylitol is used as a sweetener in many products, including chewing gum, candy, baked goods and toothpaste. In dogs (it is uncertain if cats are also affected), ingestion of just a minute portion can cause liver failure. The increase in insulin leads to hypoglycemia (lowered sugar levels). Initial signs of toxicosis include vomiting, lethargy, depression, and loss of coordination.  Signs can progress to recumbancy and seizures. These signs can develop rapidly, in as little as 30 minutes after ingestion.  Elevated liver enzymes and liver failure can be seen within a few days.

Read more about xylitol toxicosis in dogs...