Acute hepatic steatosis: a helpful diagnostic feature in metallic phosphide-poisoned horses. Academic Article uri icon


  • Metal phosphides, particularly zinc and aluminum phosphide, occasionally poison horses and other equids following their use as rodenticides and insecticides. Grain-based aluminum phosphide baits are used to control rodents such as prairie dogs. The clinical course in intoxicated horses is short (<24-48 h), and animals may be found dead. Hepatic lesions caused by phosphine poisoning are not well described. Laboratory confirmation depends on detecting phosphine gas in gastric contents. Eight horses and a mule were exposed to zinc phosphide used to control prairie dogs on a Wyoming ranch. Three of 9 exposed equids developed some combination of sweating, ataxia, anxiety, and colic; 2 died acutely, and 1 recovered. A diagnosis of zinc phosphide was made by detecting phosphine in stomach contents from a horse and a mule. The liver was pale and swollen in the affected horse, which died after a clinical course of ~12 h. Other changes were generalized congestion and edema, pulmonary edema, and acute cerebrocortical edema. There was diffuse hepatocellular microvesicular steatosis. Similar histologic lesions were present in 7 equine livers from 2 previously published episodes of metallic phosphide poisoning. Older lesions (>24 h of clinical signs) had centrilobular hepatic necrosis with congestion and a mixture of microvesicular and macrovesicular steatosis. Phosphine poisoning should be considered in horses that die acutely and are found to have steatosis, either with or without hepatocellular necrosis.

published proceedings

  • J Vet Diagn Invest

altmetric score

  • 0.25

author list (cited authors)

  • Fox, J. H., Porter, B. F., Easterwood, L., Hildenbrand, J., Hlie, P., Smylie, J., & O'Toole, D.

citation count

  • 0

complete list of authors

  • Fox, Jonathan H||Porter, Brian F||Easterwood, Leslie||Hildenbrand, Justin RV||Hélie, Pierre||Smylie, James||O'Toole, Donal

publication date

  • March 2018