Theobromine poisoning
Encyclopedia
| Animal | Oral Mouth The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth.... toxicity Toxicity Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver... (mg/kg Kilogram The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water... ) |
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| TD Lowest published toxic dose In toxicology, the Lowest published toxic dose is the lowest dosage per unit of bodyweight of a substance known to have produced signs of toxicity in a particular animal species... Lo |
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| Cat Cat The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests... |
200 | |
| Dog Dog The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in... |
16 | 300 |
| Human Human Humans are the only living species in the Homo genus... |
26 | ~1000 |
| Mouse Mouse A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles... |
837 | |
| Rat Rat Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus... |
1265 | |
Theobromine poisoning or chocolate poisoning is an adverse reaction to the alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
theobromine
Theobromine
Theobromine , also known as xantheose, is a bitter alkaloid of the cacao plant, with the chemical formula C7H8N4O2. It is found in chocolate, as well as in a number of other foods, including the leaves of the tea plant, and the kola nut...
, found in chocolate
Chocolate
Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...
, tea
Tea
Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...
, cola
Cola
Cola is a carbonated beverage that was typically flavored by the kola nut as well as vanilla and other flavorings, however, some colas are now flavored artificially. It became popular worldwide after druggist John Pemberton invented Coca-Cola in 1886...
beverages, açaí berries, and some other foods. Cacao beans contain about 1.2% theobromine by weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...
, while processed chocolate, in general, has smaller amounts. The amount found in highly refined chocolate candies (typically or per ounce
Ounce
The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
) is much lower than that of dark chocolate or unsweetened baker's chocolate
Baker's chocolate (brand)
Baker's Chocolate is a brand name for the line of baking chocolates made by the Kraft Foods corporation. Products include a variety of bulk chocolates, including white and unsweetened, and sweetened coconut flakes...
( or ).
In general, the amount of theobromine found in chocolate is small enough such that chocolate can be safely consumed by human
Human
Humans are the only living species in the Homo genus...
s. However occasional serious side effects may result from the consumption of large quantities, especially in the elderly. In extreme cases, emergency room treatment may be required.
Serious poisoning happens more frequently in domestic animals, which metabolize theobromine much more slowly than humans, and can easily consume enough chocolate to cause chocolate poisoning. The most common victims of theobromine poisoning are dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s, for which it can be fatal. The toxic dose for cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s is even lower than for dogs. However, cats are less prone to eating chocolate since they are unable to taste sweetness. Theobromine is much less toxic to rats and mice, due to their relative genetic similarity to primates; they and humans all have an LD50 about 1000 mg/kg.
Toxic (LD50
LD50
In toxicology, the median lethal dose, LD50 , LC50 or LCt50 of a toxin, radiation, or pathogen is the dose required to kill half the members of a tested population after a specified test duration...
) doses of theobromine have only been published for humans, cats, dogs, rats, and mice; these differ by a factor of 6 across species (see the table in this article). The toxicity for (pet) birds is not known, but it is typically assumed that chocolate is dangerous for birds, especially since birds like to eat chocolate.
The first signs of theobromine poisoning are nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
, and increased urination
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...
. These can progress to cardiac arrhythmias, epileptic seizures, internal bleeding
Internal bleeding
Internal bleeding is bleeding occurring inside the body. It can be a serious medical emergency depending on where it occurs , and can potentially cause death and cardiac arrest if proper medical treatment is not received quickly....
, heart attacks
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
, and eventually death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
.
In dogs, the half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of theobromine is 17.5 hours, so in severe cases clinical symptoms of theobromine poisoning can persist for 72 hours. Medical treatment performed by a veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
involves inducing vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
within two hours of ingestion and administration of benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
s or barbiturate
Barbiturate
Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, as hypnotics, and as anticonvulsants...
s for seizures, antiarrhythmics for heart arrhythmias, and fluid diuresis
Forced diuresis
Forced diuresis may enhance the excretion of certain drugs in urine and is used to treat drug overdose or poisoning of these drugs and hemorrhagic cystitis.-Diuretics:...
.
A typical dog will normally experience intestinal distress after eating less than 240 g (8.5 oz) of dark chocolate, but won't necessarily experience bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
or tachyarrhythmia unless it eats at least half a kilogram (1.1 lb) of milk chocolate. According to the Merck Veterinary Manual
Merck Veterinary Manual
The Merck Veterinary Manual is a reference manual of animal health care. It is published by Merck & Co., Inc. and Merial Limited. The Merck Veterinary Manual is available as a reference manual or as an online resource for veterinarians, veterinary students, and others involved in animal health...
, approximately of baker's chocolate per kilogram of a dog's body weight (0.02 oz/lb) is sufficient to cause symptoms of toxicity. For example, a typical 25-gram (1-ounce) baker's chocolate bar would be enough to bring out symptoms in a 20-kilogram (44-pound) dog. Large breeds (>100 lbs) can safely consume chocolate in limited quantities, but care must still be taken, as they can safely eat only about a quarter the amount a human can, and should not be intentionally fed it; peanut butter
Peanut butter
Peanut butter is a food paste made primarily from ground dry roasted peanuts, popular in North America, Netherlands, United Kingdom, and parts of Asia, particularly the Philippines and Indonesia. It is mainly used as a sandwich spread, sometimes in combination as in the peanut butter and jelly...
is often recommended as a safer alternative.
Chemists with the USDA are investigating the use of theobromine as a toxicant to control coyotes that prey on livestock.