Ingestion of chocolate can cause a serious and potentially fatal toxicity in pets if left untreated.
Theobromine and Caffeine Toxicities
Chocolate toxicity is most often seen in dogs, but occasionally does occur in cats and other pets. Generally a reaction occurs when the pet gets into chocolate left within reach, but it can also be caused by well-meaning owners giving chocolate as a treat.
Chocolate contains two ingredients which are toxic to pets: theobromine and caffeine. Theobromine causes the release of catacholamines into the animal’s system. These stimulate the sympathetic nervous system, which is responsible for the body’s fight/flight response. An example of a catecholamine is epinephrine. Caffeine directly stimulates the heart muscle and the central nervous system. Together, this makes these two chemicals a potent pair.
The amount of caffeine and theobromine found in chocolate depends on the type. White chocolate is much less toxic to pets then dark chocolate or unsweetened cocoa powder. For example: a 60 lb lab could eat up to half of a pound, or 8.5 oz of milk chocolate before showing mild symptoms, but the same dog eating half of a pound of unsweetened baking chocolate would have a potentially fatal reaction. The lab would only need to eat 1.2 oz before showing symptoms of toxicity. Different sources disagree on the amount of chocolate needed to cause toxicity, but the Handbook of Small Animal Toxicology and Poisonings reports mild to moderate signs in animals ingesting 20mg/kg or 9 mg/lb of body weight and life threatening signs at 60 mg/kg or 27 mg/lb of body weight.
Symptoms of Chocolate Toxicity (Gfeller & Messonier, 2004).
- increased heart rate
- increased respiration rate, panting
- nervousness, exciteability, hyperactivity
- hyperthermia, or increased body temperature
- tremors, seizures
- cardiac arrythmias
- coma and death
There is no antidote for chocolate toxicity; treatment is aimed at supporting the animal’s system and treating any symptoms that may appear. The Handbook of Small Animal Toxicology and Poisonings recommends inducing vomiting on the pet, followed by activated charcoal to help bind to the theobromine and caffeine before they enter the bloodstream. If the chocolate was recently ingested and the pet isn’t showing any signs, the owner may observe the animal at home. If however, the animal is showing symptoms of chocolate toxicity such as an increased heart rate or hyperactivity, hospitalization is recommended. The pet should be placed on intravenous fluids to prevent dehydration, to help flush the toxic compounds from the animal’s blood stream and to correct any blood abnormalities. If needed, seizures and tremoring may be controlled using diazepam or possibly a narcotic if the diazepam is unsuccessful. Sedation may also be necessary to control hyperactivity and nervousness. An ECG, or electrocardiogram is also recommended to check the heart’s rhythm for any abnormalities. (Gfeller & Messonier, 2004)
Prevention is the best way to protect your pet from chocolate toxicity. Keep chocolate out of your pet’s reach and never give chocolate or any treats containing chocolate to your pet. If your pet does ingest chocolate, contact your veterinarian immediately because the sooner treatment is started, the better the pet’s chances for a full recovery will be. Also, be sure to note what type of chocolate your pet got into and how much.
(2004). Chocolate and Caffeine Poisoning. In R. Gfeller, & S. Messonier, Handbook of Small Animal Toxicology and Poisonings (pp. 130-134). St. Louis: Mosby.