Theobromine is a chemical substance naturally occurring in cocoa beans, tea plant leaves, and kola nuts (Gans, Korson, Cater & Ackerly 481). It belongs to a family of chemicals called methylxanthines. It has been consumed by humans for centuries. Cocoa bean husks are added to animal feeds in cocoa producing regions. Theobromine poisoning can occur when large amounts of the chemical are ingested.
Dogs, cats, rodents, cattle, horses and pigs can be intoxicated by theobromine. Dogs are by far the most susceptible farm animals. This paper will discuss the mechanism, signs and symptoms, treatment, and prevention of theobromine poisoning in animals.
Toxicity in dogs and cats follows ingestion of a lot chocolate. Different types of chocolate contain different concentrations of theobromine. Ingestion of large amounts of the alkaloid can cause death. Dogs are likely to get intoxicated because they like sweet food (Drolet et. al 902). Husks fed to cattle may contain high concentrations of theobromine.
Toxicity correlates well with concentration of the chemical and the weight of the animal (toxicity is caused by an overdose). Small animals are likely to be affected by small amounts of the chemical. The lethal dose, also known as LD50, of theobromine is 100 to 200mg per kilogram (Gwaltney-Brant 1). However, as little as 20mg per kilogram can cause serious poisoning.
Theobromine exerts its effect by inhibiting phosphodiesterase and blocking adenosine receptors. The net result is prolonged effect of cyclic adenosine monophosphate (cAMP). Cyclic adenosine monophosphate is a second messenger in excitatory pathways. Signs and symptoms of toxicity are a result of exaggerated pharmacological effects of the chemical. Toxicity in animals is related to ability to metabolize the compound.
Animals like dogs, cats and horses break it down slowly. The average half life of theobromine in dogs is above 17 hours. Body systems react to theobromine differently. However, theobromine is primarily a vasodilator, a bronchodilator, and a heart stimulant. It also causes increased urine output.
Signs and symptoms vary depending on the animal affected. Generally, initial signs and symptoms of toxicity in animals are diarrhoea, hyper-excitability, nausea, vomiting, and increased urinary urgency.
Signs and symptoms of life threatening toxicity are bradycardia, tachycardia, seizures, internal bleeding, and heart attacks. Dogs and rodents may suffer additional problems like testicular damage. Theobromine toxicity in cattle reduces the amount of milk. Thyroid and hepatic toxicity occurs in horses.
Animals presenting with theobromine poisoning can be treated symptomatically. A veterinary doctor can either induce vomiting or administer an active agent that can block the effects of the chemical. Other treatment modalities include management of seizures and cardiac arrhythmias.
Seizures are treated using anticonvulsants like barbiturates and benzodiazepines (Boothe 387). Cardiac toxicity can be treated using thiazides (Plumb 118). Fluid replacement is initiated to restore fluid and electrolytes balance.
Farmers and pet owners should be aware of the danger posed by theobromine. Clients should be informed that cats and dogs are particularly vulnerable to the chemical. Farmers should not allow farm animals and pets to eat chocolate. If signs and symptoms of theobromine toxicity appear, clients should call a veterinary doctor immediately.
Theobromine poisoning is caused by ingestion of large amounts of the chemical. The chemical is naturally occurring in cocoa plants and tea plants. Signs and symptoms include hyper-excitability, diarrhoea, vomiting, arrhythmias, and seizures. Toxicity can be treated using barbiturates and benzodiazepines.
Works Cited
Boothe, Dawn. “Anticonvulsant drugs and Analeptic Agents.” Veterinary Pharmacology and Therapeutics. Ed. H. R. Adams. Ames, IA: Iowa State University Press, 2001. 387-388. Print.
Drolet et al. “Cacao Bean Shell Poisoning in a Dog.” J. Am. Vet. Med. Association 185.8 (1984): 902. Print.
Gans, Joseph, Roy Korson, Marilyn Cater & Cynthia Ackerly. “Effects of short-term and long-term theobromine administration to male dogs.” Toxicology and Applied Pharmacology.53.3 (1980): 481–496. Web.
Gwaltney-Brant, Sharon. 2001. Chocolate intoxication. PDF file. Web.
Plumb, Donald. Veterinary Drug Handbook, Ames, IA: Iowa State University Press, 1999. Print.