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 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.
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.
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
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).
Porter, Brian F
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).
Easterwood, Leslie
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).
Hildenbrand, Justin R V
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).
Hélie, Pierre
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).
Smylie, James
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).
O'Toole, Donal
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.