Cyanide Toxicosis

Cyanide Toxicosis



Basic Information image



Definition


Cyanide poisoning in animals usually results from ingestion of plants containing cyanogenic glycosides. Poisoning may also occur when cyanide is inhaled as gaseous hydrogen cyanide or is ingested in the chemical forms of sodium and potassium cyanide, but these causes are very uncommon in animals. Cyanide poisoning is rare in horses.



Synonym(s)




• Prussic acid poisoning


• Hydrogen cyanide (HCN) poisoning



Epidemiology



Species, Age, Sex


All ages and species of mammals are susceptible to cyanide poisoning.



Geography and Seasonality


There are at least 2500 plant species in many plant families, including the Asteraceae, Chenopodiaceae, Euphorbiaceae, Fabaceae, Juncaginaceae, Linaceae, Poaceae, and Rosaceae, that are known to contain cyanogenic glycosides. A few of the more common plants with cyanogenic potential include service berry, elderberry, Johnson grass, Sudan grass, arrow grass, corn, cherry laurel, wild cherry, and chokecherry.



Clinical Presentation



Disease Forms/Subtypes




• Acute cyanide poisoning


• Chronic cyanide poisoning is discussed in “Sorghum and Sudan Grass Toxicosis” in this section



History, Chief Complaint


Sudden death is usually the presenting feature of cyanide poisoning.



Physical Exam Findings




• Severe dyspnea, open-mouthed breathing, staggering gait, prostration


• Mucous membranes initially are congested and bright red, becoming cyanotic near death.


• A lethal dose of cyanide results in death within a few minutes to 1 hour.



Etiology and Pathophysiology




• Cyanide reversibly inhibits mitochondrial cytochrome oxidase and blocks electron transport, resulting in decreased oxidative metabolism and oxygen utilization.


• Plant-associated cyanide toxicity depends on enzymatic hydrolysis of cyanogenic glycosides that liberates the toxic cyanide ion responsible for toxicity. Plants do not contain free HCN because the cyanogenic glycosides and the hydrolyzing enzymes are compartmentalized in the plant.


• Damage to the plant cell compartments is necessary to start the hydrolytic process. Optimally, this occurs at a pH greater than 4 or when the plants are damaged as a result of drought, wilting, freezing, or crushing.


• Plant-induced acute cyanide poisoning in horses is poorly documented in the literature, but cyanide poisoning in ruminants is well documented. This species difference is related to the ability of rumenal digestive microflora to rapidly hydrolyze cyanogenic glycosides and the low pH of the horse’s stomach in contrast to the more alkaline pH of the rumen.


• Plant cyanide-producing potential is highest in new growth and declines significantly as leaves mature.

< div class='tao-gold-member'>

Related posts:

  1. Aggressive Stallion Behavior
  2. Aflatoxin Toxicosis
  3. Biliary Atresia
  4. Black Widow Spider Toxicosis

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 24, 2016 | Posted by in SMALL ANIMAL | Comments Off on Cyanide Toxicosis

Full access? Get Clinical Tree
Get Clinical Tree app for offline access