What Do We Know About Hepatitis Viruses in Horses?
Abstract: Theiler disease (serum hepatitis or idiopathic acute hepatic necrosis) has long been suspected to have a viral etiology. Four viruses have been described in association with hepatitis in horses. Further investigation suggests equine pegivirus and Theiler disease-associated virus (a second pegivirus) are neither hepatotropic nor pathogenic. Nonprimate hepacivirus (NPHV) causes subclinical disease in experimental models and has been associated with hepatitis in some clinical cases. Equine parvovirus-hepatitis (EqPV-H) experimentally causes subclinical-to-clinical liver disease and is found in the vast majority of Theiler disease cases. EqPV-H is likely of clinical significance, whereas the significance of NPHV is unknown.
Copyright © 2019 Elsevier Inc. All rights reserved.
Publication Date: 2019-05-10 PubMed ID: 31084975DOI: 10.1016/j.cveq.2019.03.001Google 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.
- Journal Article
- Review
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.
Theiler disease, also known as serum hepatitis or idiopathic acute hepatic necrosis in horses, may be caused by the Equine parvovirus-hepatitis (EqPV-H), while the role of Nonprimate hepacivirus (NPHV) remains uncertain.
Background
- Theiler disease is also referred to as serum hepatitis or idiopathic acute hepatic necrosis in horses.
- It has been suspected for a long time that a virus might be the cause of Theiler disease.
- Four viruses have previously been associated with liver disease in horses.
Research Findings on Various Viruses
- Both equine pegivirus and Theiler disease-associated virus (which is another pegivirus) have been investigated. It was found that:
- They are not attracted to the liver (non-hepatotropic).
- They are not disease-causing (non-pathogenic).
- Nonprimate hepacivirus (NPHV):
- Causes mild or no symptoms in experimental models.
- Has been linked to liver disease in some real-world cases.
- Its clinical significance remains uncertain.
- Equine parvovirus-hepatitis (EqPV-H):
- Can cause a range of liver disease, from no symptoms to full-blown disease, in experimental settings.
- Is present in most cases of Theiler disease.
- Is likely a significant cause of liver disease in horses.
Conclusion
- Of the viruses studied, Equine parvovirus-hepatitis (EqPV-H) is likely the main virus of concern in relation to Theiler disease.
- The role and importance of Nonprimate hepacivirus (NPHV) in causing liver disease in horses is still not clear and needs further investigation.
Cite This Article
APA
Tomlinson JE, Van de Walle GR, Divers TJ.
(2019).
What Do We Know About Hepatitis Viruses in Horses?
Vet Clin North Am Equine Pract, 35(2), 351-362.
https://doi.org/10.1016/j.cveq.2019.03.001 Publication
Researcher Affiliations
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, 235 Hungerford Hill Road, Ithaca, NY 14853, USA. Electronic address: jet37@cornell.edu.
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, 235 Hungerford Hill Road, Ithaca, NY 14853, USA.
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, 930 Campus Road, Box25, Ithaca, NY 14853, USA.
MeSH Terms
- Animals
- Hepatitis Viruses / isolation & purification
- Hepatitis Viruses / pathogenicity
- Hepatitis Viruses / physiology
- Hepatitis, Viral, Animal / virology
- Horse Diseases / pathology
- Horse Diseases / virology
- Horses
Citations
This article has been cited 13 times.- Pourmahdi Borujeni M, Ghobadian Diali H, Mashhadi AG, Aliabad MJ. First Detection and Phylogenetic Analysis of Equine Hepacivirus (EqHV) in Iran. Vet Med Sci 2026 Jan;12(1):e70737.
- Scupham AJ. Equine Parvovirus-Hepatitis Population Dynamics in a Single Horse over 16 Years. Viruses 2025 Jul 4;17(7).
- Frisch V, Ramsauer AS, Preining I, Unterköfler MS, Fuehrer HP, Hofer M, Lyrakis M, Bouhsira E, Liénard E, Cavalleri JV. First detection of equine hepacivirus RNA in Stomoxys calcitrans (Diptera, Muscidae) in eastern Austria. BMC Vet Res 2025 Jul 17;21(1):474.
- Scupham AJ, Tong C. Detection of equine parvovirus-hepatitis and efficacy of governmental regulation for equine biologics purity. J Vet Diagn Invest 2025 Jan;37(1):79-85.
- Fortier C, El-Hage C, Normand C, Hue ES, Sutton G, Marcillaud-Pitel C, Jeffers K, Bamford N, Oden E, Paillot R, Hartley C, Gilkerson J, Pronost S. Detection of Equine Parvovirus-Hepatitis Virus and Equine Hepacivirus in Archived Sera from Horses in France and Australia. Viruses 2024 May 28;16(6).
- Mashin VV, Sergeev AN, Martynova NN, Oganov MD, Sergeev AA, Kataeva VV, Zagidullin NV. Ensuring Viral Safety of Equine Immunoglobulins during Production. Pharm Chem J 2022;56(2):283-288.
- Lee SK, Park D, Lee I. Molecular Prevalence of Equine Parvovirus-Hepatitis in the Sera of Clinically Healthy Horses in South Korea. Vet Sci 2021 Nov 19;8(11).
- Yoon J, Park T, Kim A, Song H, Park BJ, Ahn HS, Go HJ, Kim DH, Lee JB, Park SY, Song CS, Lee SW, Choi IS. First Detection and Genetic Characterization of New Equine Parvovirus Species Circulating among Horses in Korea. Vet Sci 2021 Nov 7;8(11).
- Yoon J, Park T, Kim A, Park J, Park BJ, Ahn HS, Go HJ, Kim DH, Jung S, Seo Y, Lee JB, Park SY, Song CS, Lee SW, Choi IS. First Clinical Case of Equine Parvovirus-Hepatitis-Related Theiler's Disease in Asia. Viruses 2021 Sep 24;13(10).
- Ramsauer AS, Badenhorst M, Cavalleri JV. Equine parvovirus hepatitis. Equine Vet J 2021 Sep;53(5):886-894.
- Badenhorst M, de Heus P, Auer A, Tegtmeyer B, Stang A, Dimmel K, Tichy A, Kubacki J, Bachofen C, Steinmann E, Cavalleri JMV. Active equine parvovirus-hepatitis infection is most frequently detected in Austrian horses of advanced age. Equine Vet J 2022 Mar;54(2):379-389.
- Tomlinson JE, Jager M, Struzyna A, Laverack M, Fortier LA, Dubovi E, Foil LD, Burbelo PD, Divers TJ, Van de Walle GR. Tropism, pathology, and transmission of equine parvovirus-hepatitis. Emerg Microbes Infect 2020;9(1):651-663.
- Meister TL, Tegtmeyer B, Brüggemann Y, Sieme H, Feige K, Todt D, Stang A, Cavalleri JV, Steinmann E. Characterization of Equine Parvovirus in Thoroughbred Breeding Horses from Germany. Viruses 2019 Oct 18;11(10).
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