Acute hepatic steatosis: a helpful diagnostic feature in metallic phosphide-poisoned horses.
Abstract: 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.
Publication Date: 2017-12-04 PubMed ID: 29202675PubMed Central: PMC6505880DOI: 10.1177/1040638717746707Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Case Reports
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research paper reports on a study examining the effect of metallic phosphides, particularly zinc and aluminum phosphide, on horses. The study finds that acute hepatic steatosis can serve as a diagnostic tool for metallic phosphide poisoning in these animals.
Introduction
- The paper begins by noting that metallic phosphides, particularly zinc and aluminum, can occasionally poison horses and other equids following their use as rodenticides or insecticides.
- Aluminum phosphide baits made from grains are often used to control rodents like prairie dogs.
- The duration of the toxic episode in the affected horses is relatively short, often within 24-48 hours, and in many cases, the animals may be found dead.
Experiment and Results
- The researchers used a case example involving eight horses and a mule from a Wyoming ranch, where zinc phosphide was being used to control prairie dogs.
- Out of the nine equids that were exposed to the metallic phosphide, three developed varying combinations of sweating, ataxia, anxiety, and colic symptoms.
- Two of these animals died quickly due to the exposure, while one equid was able to recover.
- A diagnosis of zinc phosphide poisoning was established by detecting the presence of phosphine gas in the stomach contents of a horse and a mule.
Findings
- In the horse that died after exposure, the researchers found that their liver was pale and swollen. This, along with other symptoms such as generalized congestion and edema, pulmonary edema, and acute cerebrocortical edema, pointed towards acute hepatic steatosis.
- They also found similar histological lesions in seven other equine livers from two previous episodes of metallic phosphide poisoning.
- The older lesions, those that had indications of more than 24 hours of clinical signs, revealed centrilobular hepatic necrosis with a mixture of microvesicular and macrovesicular steatosis.
Conclusion
- The paper, in conclusion, poses that phosphine poisoning should be a consideration for veterinarians examining horses that have died suddenly, and have either steatosis—with or without hepatocellular necrosis.
- The research suggests that acute hepatic steatosis can, therefore, be a key diagnostic feature when investigating cases of metallic phosphide poisoning in equids.
Cite This Article
APA
Fox JH, Porter BF, Easterwood L, Hildenbrand JRV, Hélie P, Smylie J, O'Toole D.
(2017).
Acute hepatic steatosis: a helpful diagnostic feature in metallic phosphide-poisoned horses.
J Vet Diagn Invest, 30(2), 280-285.
https://doi.org/10.1177/1040638717746707 Publication
Researcher Affiliations
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
- Wyoming State Veterinary Laboratory, University of Wyoming, Laramie WY (Fox, Hildenbrand, O'Toole).
- Departments of Veterinary Pathobiology (Porter), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Large Animal Clinical Sciences (Easterwood), College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX.
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St. Hyacinthe, Q, Canada (Hélie).
- Smylie Veterinary Clinic, Douglas, WY (Smylie).
MeSH Terms
- Aluminum Compounds / poisoning
- Animals
- Diagnosis, Differential
- Equidae
- Female
- Gastrointestinal Contents / chemistry
- Horse Diseases / diagnosis
- Horses
- Insecticides / poisoning
- Liver Diseases / pathology
- Male
- Phosphines / poisoning
- Poisoning / diagnosis
- Poisoning / veterinary
- Rodenticides / poisoning
- Wyoming
- Zinc Compounds / poisoning
Conflict of Interest Statement
Declaration of conflicting interests: The authors declared no potential conflicts of interest with respect tothe research, authorship, and/or publication of this article.
References
This article includes 21 references
- Anonymous. Occupational phosphine gas poisoning at veterinary hospitals from dogs that ingested zinc phosphide—Michigan, Iowa, and Washington, 2006–2011.. Morb Mortal Wkly Rep 2012;61:286–288.
- Begriche K. Drug-induced toxicity on mitochondria and lipid metabolism: mechanistic diversity and deleterious consequences for the liver.. J Hepatol 2011;54:773–794.
- Bildfell RJ. A review of episodes of zinc phosphide toxicosis in wild geese (Branta spp.) in Oregon (2004–2011).. J Vet Diagn Invest 2013;25:162–167.
- Casteel SW, Bailey EM Jr. A review of zinc phosphide poisoning.. Vet Hum Toxicol 1986;28:151–154.
- Cullen JM, Stalker MJ. Liver and biliary system.. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals 2016;6th ed. Vol. 2 Philadelphia, PA: Elsevier:273–278.
- Drolet R. Zinc phosphide poisoning in a horse.. Equine Vet J 1996;28:161–162.
- Eason C. Toxicology and ecotoxicology of zinc phosphide as used for pest control in New Zealand.. N Z J Ecol 2013;37:1–11.
- Easterwood L. Phosphine intoxication following oral exposure of horses to aluminum phosphide-treated feed.. J Am Vet Med Assoc 2010;236:446–450.
- Gray SL. Potential zinc phosphide rodenticide toxicosis in dogs: 362 cases (2004–2009).. J Am Vet Med Assoc 2011;239:646–651.
- Hernández Olivares CP. Zinc phosphide poisoning in a mare.. Vet Mex 2002;33:343–346.
- Ingram PL. Zinc phosphide poisoning in a colt.. Vet Rec 1945;57:103–104.
- Knight MW. Zinc phosphide.. Small Animal Toxicology 2006;2nd ed. St. Louis, MO: Elsevier Saunders:1101–1118.
- Lee RG. Diagnostic Liver Pathology.. 1994;St. Louis, MO: Mosby Year Books:167–175, 348–349.
- Nagy AL. Intentional fatal metallic phosphide poisoning in a dog—a case report.. BMC Vet Res 2015;11:158.
- Osweiler GD. Phosphides of zinc, aluminum, or calcium.. Toxicology 1996;Philadelphia, PA: Williams & Wilkins:282–284.
- Plumlee KH. Pesticide toxicosis in the horse.. Vet Clin North Am Equine Pract 2001;17:491–500.
- Proudfoot AT. Aluminium and zinc phosphide poisoning.. Clin Toxicol (Phila) 2009;47:89–100.
- Robertson A. Experimental zinc phosphide poisoning in fowls.. J Comp Pathol 1945;55:290–300.
- Robison WH, Hilton HW. Gas chromatography of phosphine derived from zinc phosphide in sugarcane.. J Agric Food Chem 1971;19:875–878.
- Saleki S. Liver histopathology of fatal phosphine poisoning.. Forensic Sci Int 2007;166:190–193.
- Zadura J, Niec L. Masowe zatrucie u koni fosforkiem cynku [Poisoning of horses with zinc phosphide].. Med Vet Varsovie 1953;9:550–551.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
