Equine veterinary journal2018; 51(3); 304-309; doi: 10.1111/evj.13029

Chronic iron overload causing haemochromatosis and hepatopathy in 21 horses and one donkey.

Abstract: Iron toxicosis is rarely reported in horses and chronic excessive oral iron intake has not been reported to cause clinical symptoms in equids. Objective: This case series describes 21 genetically unrelated horses and one donkey with chronic iron overload causing haemochromatosis and hepatopathy. Methods: Case series. Methods: All equids showing clinical signs compatible with chronic liver disease presented to Utrecht University and diagnosed with iron overload and haemochromatosis based on histopathological evaluation of liver tissue and/or blood transferrin saturation levels of >80% and proof of excess dietary iron intake due to excess iron content in drinking water were included. Results: This study included 22 equids. All tested animals (n = 19) had transferrin saturation >80% and 21 of 22 had increased gamma-glutamyltransferase (γGT). Ultrasonography revealed rounded liver margins in five out of six horses and increased echogenicity in 4/6. Histological examination of liver tissue of 12 animals showed hepatitis, fibrosis and haemosiderin accumulation in macrophages and hepatocytes. Post-mortem examination also revealed haemosiderin accumulation in other organs in all seven examined animals. High iron content in drinking water was identified as the source of iron overload in all cases. All animals were housed under the same conditions for a minimum of 9 years prior to diagnosis of haemochromatosis. Of 22 animals, 13 survived until 1 January 2018, ranging from 17 to 79 months post diagnosis. Conclusions: Histology of liver tissue was not available for 10 of 22 cases. Conclusions: Chronic iron overload can lead to haemochromatosis and hepatopathy in equids. Development of disease is slow and clinical signs are nonspecific. Long-term excessive iron intake in equids should be avoided. If animals drink from natural water sources, it is important to test the water for iron content. The Summary is available in Spanish - see Supporting Information.
Publication Date: 2018-11-05 PubMed ID: 30269378DOI: 10.1111/evj.13029Google Scholar: Lookup
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  • Journal Article

Summary

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The research paper details a study that investigates cases of chronic iron overload in 21 unrelated horses and one donkey, leading to haemochromatosis and liver disease. Source of the iron overload was found to be high iron content in drinking water.

Objective and Methodology

  • The objective of the case series was to investigate instances of chronic iron overload causing haemochromatosis and hepatopathy in 21 unrelated horses and one donkey.
  • The research used animals that were presenting with clinical signs of chronic liver disease and were then diagnosed with iron overload and haemochromatosis.
  • The diagnoses were made based on histopathological evaluations of liver tissue and/or evidence of transferrin saturation levels being above 80% in their blood, and the confirmation of excess dietary intake of iron.

Findings and Results

  • This study included a total of 22 equids, 21 horses and one donkey.
  • All tested animals had transferrin saturation levels above 80% and 21 out of 22 had increased level of gamma-glutamyltransferase, an enzyme that indicates liver disease.
  • Ultrasonography performed on six horses revealed rounded liver margins in five of them and increased echogenicity in four.
  • When examining the liver tissues of 12 animals histologically, they revealed inflammation of the liver, fibrosis (scarring), and haemosiderin (iron) accumulation in macrophages and hepatocytes (liver cells).
  • In post-mortem examinations, all seven animals revealed haemosiderin accumulation in other organs as well.
  • All the animals had been exposed to high iron content in drinking water for at least nine years before being diagnosed with haemochromatosis.
  • Regarding the survival rate, 13 of the 22 animals were still alive by 1 January 2018, ranging from 17 to 79 months post their initial diagnosis.

Conclusions

  • For 10 out of the 22 cases, liver tissue histology was not available for assessment.
  • The research concluded that chronic iron overload can indeed lead to haemochromatosis and hepatopathy in equids.
  • The development of these symptoms is slow and their clinical signs are nonspecific, making it a stealthy and dangerous condition.
  • The conclusion also emphasises the importance of avoiding long-term excessive iron intake in equids (horses).
  • For animals drinking from natural water sources, it is important to regularly test the water for its iron content to prevent such chronic conditions.

Cite This Article

APA
Theelen MJP, Beukers M, Grinwis GCM, Sloet van Oldruitenborgh-Oosterbaan MM. (2018). Chronic iron overload causing haemochromatosis and hepatopathy in 21 horses and one donkey. Equine Vet J, 51(3), 304-309. https://doi.org/10.1111/evj.13029

Publication

ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 51
Issue: 3
Pages: 304-309

Researcher Affiliations

Theelen, M J P
  • Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
Beukers, M
  • Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
Grinwis, G C M
  • Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
Sloet van Oldruitenborgh-Oosterbaan, M M
  • Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.

MeSH Terms

  • Animals
  • Equidae
  • Female
  • Horse Diseases / diagnosis
  • Horse Diseases / pathology
  • Horses
  • Iron Overload / diagnosis
  • Iron Overload / pathology
  • Iron Overload / veterinary
  • Liver Diseases / diagnosis
  • Liver Diseases / etiology
  • Liver Diseases / pathology
  • Liver Diseases / veterinary
  • Male

Grant Funding

  • The Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands

Citations

This article has been cited 7 times.
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    doi: 10.5194/aab-66-197-2023pubmed: 37560356google scholar: lookup
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  7. Kellon EM, Gustafson KM. Possible dysmetabolic hyperferritinemia in hyperinsulinemic horses.. Open Vet J 2020 Jan;9(4):287-293.
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