{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T19:17:27Z","timestamp":1780427847821,"version":"3.54.1"},"reference-count":32,"publisher":"American Veterinary Medical Association (AVMA)","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["javma"],"published-print":{"date-parts":[[2023,2,1]]},"abstract":"Abstract<\/jats:title>\n\nOBJECTIVE<\/jats:title>\nTo report history, clinical examination findings, clinicopathologic findings, diagnostic test results, treatment, and outcome in horses with a novel idiopathic hepatitis syndrome.<\/jats:p>\n<\/jats:sec>\n\nANIMALS<\/jats:title>\n13 client-owned horses.<\/jats:p>\n<\/jats:sec>\n\nPROCEDURES<\/jats:title>\nMedical records of horses that were presented with fever and increased blood liver enzyme activity over a 16-month period were reviewed (December 1, 2020, to April 1, 2022). Collected data included signalment, history, clinical and clinicopathologic findings, diagnostic test results, treatment, clinical progression, and short-term outcome.<\/jats:p>\n<\/jats:sec>\n\nRESULTS<\/jats:title>\nAffected horses were presented between December and April of each of the 2 seasons investigated. The majority of horses developed cyclic fevers over the course of 3 weeks, during which time histologic evidence of hepatitis was observed. Histologic lesions included hepatic necrosis, neutrophilic to lymphohistiocytic inflammation, biliary epithelial injury, and portal fibrosis. Systemic inflammation was evidenced by increased serum amyloid A concentration and leukon changes. No horse developed signs of hepatic insufficiency, and all horses clinically recovered. Return of serum activity of GGT to within the reference range occurred within 16 weeks in most horses. Histologic lesions remained evident up to 27 weeks after initial presentation in 1 horse.<\/jats:p>\n<\/jats:sec>\n\nCLINICAL RELEVANCE<\/jats:title>\nAlthough an etiologic agent has not been identified, an apparently seasonal equine hepatitis syndrome was characterized by fever, systemic inflammation, increased liver enzyme activity, and histologic evidence of hepatitis. An infectious cause is suspected on the basis of histology and outcome.<\/jats:p>\n<\/jats:sec>","DOI":"10.2460\/javma.22.08.0368","type":"journal-article","created":{"date-parts":[[2022,12,7]],"date-time":"2022-12-07T16:52:37Z","timestamp":1670431957000},"page":"266-272","source":"Crossref","is-referenced-by-count":3,"title":["A seasonal idiopathic hepatitis syndrome in horses presented to a Midwestern veterinary teaching hospital"],"prefix":"10.2460","volume":"261","author":[{"given":"Sandra D.","family":"Taylor","sequence":"first","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Janice E.","family":"Kritchevsky","sequence":"additional","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrick","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carla","family":"Olave","sequence":"additional","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah J.","family":"Waxman","sequence":"additional","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Margaret A.","family":"Miller","sequence":"additional","affiliation":[{"name":"Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"issue":"4","key":"ref1","series-title":"J Vet Intern Med","first-page":"583","article-title":"Suppurative cholangiohepatitis and enteritis in adult horses","volume":"17","author":"Davis JL","year":"2003","unstructured":"Davis JL, Jones SL. Suppurative cholangiohepatitis and enteritis in adult horses. J Vet Intern Med. 2003;17(4):583\u2013587.12892313"},{"issue":"4","key":"ref2","series-title":"Equine Vet J","first-page":"301","article-title":"Medical treatment of cholangiohepatitis and cholelithiasis in mature horses: 9 cases (1991\u20131998)","volume":"32","author":"Peek SF","year":"2000","unstructured":"Peek SF, Divers TJ. Medical treatment of cholangiohepatitis and cholelithiasis in mature horses: 9 cases (1991\u20131998). Equine Vet J. 2000;32(4):301\u2013306.10952378"},{"issue":"13","key":"ref3","series-title":"Proc Natl Acad Sci U S A","first-page":"e2013982118","article-title":"A hepatitis B virus causes chronic infections in equids worldwide","volume":"118","author":"Rasche A","year":"2021","unstructured":"Rasche A, Lehmann F, Goldmann N, A hepatitis B virus causes chronic infections in equids worldwide. Proc Natl Acad Sci U S A. 2021;118(13):e2013982118. doi:10.1073\/pnas.201398211833723007"},{"issue":"1","key":"ref4","series-title":"J Vet Intern Med","first-page":"251","article-title":"Viral testing of 18 consecutive cases of equine serum hepatitis: a prospective study (2014\u20132018)","volume":"33","author":"Tomlinson JE","year":"2019","unstructured":"Tomlinson JE, Kapoor A, Kumar A, Viral testing of 18 consecutive cases of equine serum hepatitis: a prospective study (2014\u20132018). J Vet Intern Med. 2019;33(1):251\u2013257.30520162"},{"issue":"1","key":"ref5","series-title":"J Vet Intern Med","first-page":"258","article-title":"Viral testing of 10 cases of Theiler\u2019s disease and 37 in-contact horses in the absence of equine biologic product administration: a prospective study (2014\u20132018)","volume":"33","author":"Tomlinson JE","year":"2019","unstructured":"Tomlinson JE, Tennant BC, Struzyna A, Viral testing of 10 cases of Theiler\u2019s disease and 37 in-contact horses in the absence of equine biologic product administration: a prospective study (2014\u20132018). J Vet Intern Med. 2019;33(1):258\u2013265.30520132"},{"issue":"2","key":"ref6","series-title":"Emerg Infect Dis","first-page":"303","article-title":"New parvovirus associated with serum hepatitis in horses after inoculation of common biological product","volume":"24","author":"Divers TJ","year":"2018","unstructured":"Divers TJ, Tennant BC, Kumar A, New parvovirus associated with serum hepatitis in horses after inoculation of common biological product. Emerg Infect Dis. 2018;24(2):303\u2013310.29350162"},{"issue":"1","key":"ref7","series-title":"J Vet Diagn Invest","first-page":"69","article-title":"Experimental equine leukoencephalomalacia, toxic hepatosis, and encephalopathy caused by corn naturally contaminated with fumonisins","volume":"5","author":"Ross PF","year":"1993","unstructured":"Ross PF, Ledet AE, Owens DL, Experimental equine leukoencephalomalacia, toxic hepatosis, and encephalopathy caused by corn naturally contaminated with fumonisins. J Vet Diagn Invest. 1993;5(1):69\u201374.8466984"},{"issue":"3","key":"ref8","series-title":"Vet J","first-page":"270","article-title":"Toxicological effects of aflatoxins in horses","volume":"188","author":"Caloni F","year":"2011","unstructured":"Caloni F, Cortinovis C. Toxicological effects of aflatoxins in horses. Vet J. 2011;188(3):270\u2013273.20619706"},{"issue":"12","key":"ref9","series-title":"Toxins (Basel)","first-page":"356","article-title":"Dehydropyrrolizidine alkaloid toxicity, cytotoxicity, and carcinogenicity","volume":"8","author":"Stegelmeier BL","year":"2016","unstructured":"Stegelmeier BL, Colegate SM, Brown AW. Dehydropyrrolizidine alkaloid toxicity, cytotoxicity, and carcinogenicity. Toxins (Basel). 2016;8(12):356. doi:10.3390\/toxins812035627916846"},{"key":"ref10","series-title":"Toxicon","first-page":"6","article-title":"Crotalaria spectabilis poisoning in horses fed contaminating oats","volume":"197","author":"Lacerda MDSC","year":"2021","unstructured":"Lacerda MDSC, Wilson TM, Argenta VLS, Crotalaria spectabilis poisoning in horses fed contaminating oats. Toxicon. 2021;197:6\u201311.33852904"},{"issue":"9","key":"ref11","series-title":"J Am Vet Med Assoc","first-page":"1651","article-title":"Liver failure attributable to pyrrolizidine alkaloid toxicosis and associated with inspiratory dyspnea in ponies: three cases (1982\u20131988)","volume":"198","author":"Pearson EG","year":"1991","unstructured":"Pearson EG. Liver failure attributable to pyrrolizidine alkaloid toxicosis and associated with inspiratory dyspnea in ponies: three cases (1982\u20131988). J Am Vet Med Assoc. 1991;198(9):1651\u20131654.2061186"},{"issue":"12","key":"ref12","series-title":"Vet Med Small Anim Clin","first-page":"1895","article-title":"Cholangiohepatitis in a horse","volume":"75","author":"Thornburg LP","year":"1980","unstructured":"Thornburg LP, Kintner LD. Cholangiohepatitis in a horse. Vet Med Small Anim Clin. 1980;75(12):1895\u20131896."},{"issue":"2","key":"ref13","series-title":"Equine Vet Educ","first-page":"87","article-title":"Liver disease in the mature horse","volume":"11","author":"Pearson EG","year":"1999","unstructured":"Pearson EG. Liver disease in the mature horse. Equine Vet Educ. 1999;11(2):87\u201396."},{"issue":"9","key":"ref14","series-title":"Can Vet J","first-page":"746","article-title":"Cholangiohepatitis and pancreatitis secondary to severe gastroduodenal ulceration in a foal","volume":"44","author":"Buote M","year":"2003","unstructured":"Buote M. Cholangiohepatitis and pancreatitis secondary to severe gastroduodenal ulceration in a foal. Can Vet J. 2003;44(9):746\u2013748."},{"issue":"3","key":"ref15","series-title":"Vet Med Sci","first-page":"372","article-title":"Chronic equine hepacivirus infection in an adult gelding with severe hepatopathy","volume":"5","author":"Tegtmeyer B","year":"2019","unstructured":"Tegtmeyer B, Echelmeyer J, Pfankuche VM, Chronic equine hepacivirus infection in an adult gelding with severe hepatopathy. Vet Med Sci. 2019;5(3):372\u2013378."},{"issue":"1","key":"ref16","series-title":"Emerg Microbes Infect","first-page":"651","article-title":"Tropism, pathology, and transmission of equine parvovirus-hepatitis","volume":"9","author":"Tomlinson JE","year":"2020","unstructured":"Tomlinson JE, Jager M, Struzyna A, Tropism, pathology, and transmission of equine parvovirus-hepatitis. Emerg Microbes Infect. 2020;9(1):651\u2013663.32192415"},{"issue":"2","key":"ref17","series-title":"Hepatology","first-page":"447","article-title":"Clinical course of infection and viral tissue tropism of hepatitis C virus-like nonprimate hepaciviruses in horses","volume":"61","author":"Pfaender S","year":"2015","unstructured":"Pfaender S, Cavalleri JM, Walter S, Clinical course of infection and viral tissue tropism of hepatitis C virus-like nonprimate hepaciviruses in horses. Hepatology. 2015;61(2):447\u2013459.25212983"},{"issue":"5","key":"ref18","series-title":"Hepatology","first-page":"1533","article-title":"Experimental transmission of equine hepacivirus in horses as a model for hepatitis C virus","volume":"61","author":"Ramsay JD","year":"2015","unstructured":"Ramsay JD, Evanoff R, Wilkinson, TE Jr, Divers TJ, Knowles DP, Mealey RH. Experimental transmission of equine hepacivirus in horses as a model for hepatitis C virus. Hepatology. 2015;61(5):1533\u20131546."},{"issue":"4","key":"ref19","series-title":"Am J Vet Res","first-page":"572","article-title":"Pyrrolizidine alkaloid-induced liver disease in horses: an early diagnosis","volume":"49","author":"Mendel VE","year":"1988","unstructured":"Mendel VE, Witt MR, Gitchell BS, Pyrrolizidine alkaloid-induced liver disease in horses: an early diagnosis. Am J Vet Res. 1988;49(4):572\u2013578.3377320"},{"issue":"8","key":"ref20","series-title":"Am J Vet Res","first-page":"1776","article-title":"Clinicopathologic study of horses surviving pyrrolizidine alkaloid (Senecio vulgaris) toxicosis","volume":"47","author":"Lessard P","year":"1986","unstructured":"Lessard P, Wilson WD, Olander HJ, Rogers QR, Mendel VE. Clinicopathologic study of horses surviving pyrrolizidine alkaloid (Senecio vulgaris) toxicosis. Am J Vet Res. 1986;47(8):1776\u20131780.2875683"},{"issue":"6","key":"ref21","series-title":"J Vet Intern Med","first-page":"1414","article-title":"Fall panicum (Panicum dichotomiflorum) hepatotoxicosis in horses and sheep","volume":"20","author":"Johnson AL","year":"2006","unstructured":"Johnson AL, Divers TJ, Freckleton ML, Fall panicum (Panicum dichotomiflorum) hepatotoxicosis in horses and sheep. J Vet Intern Med. 2006;20(6):1414\u20131421.17186859"},{"issue":"10","key":"ref22","series-title":"Can Vet J","first-page":"602","article-title":"Hepatic disease in Alberta horses: a retrospective study of \u2018alsike clover poisoning\u2019 (1973\u20131988)","volume":"32","author":"Nation PN","year":"1991","unstructured":"Nation PN. Hepatic disease in Alberta horses: a retrospective study of \u2018alsike clover poisoning\u2019 (1973\u20131988). Can Vet J. 1991;32(10):602\u2013607.17423873"},{"issue":"2","key":"ref23","series-title":"J Vet Diagn Invest","first-page":"294","article-title":"Infectious necrotic hepatitis caused by Clostridium novyi type B in a horse: case report and review of the literature","volume":"30","author":"Nyaoke AC","year":"2018","unstructured":"Nyaoke AC, Navarro MA, Beingesser J, Uzal FA. Infectious necrotic hepatitis caused by Clostridium novyi type B in a horse: case report and review of the literature. J Vet Diagn Invest. 2018;30(2):294\u2013299."},{"issue":"5","key":"ref24","series-title":"J Vet Intern Med","first-page":"1212","article-title":"Successful treatment and polymerase chain reaction (PCR) confirmation of Tyzzer\u2019s disease in a foal and clinical and pathologic characteristics of 6 additional foals (1986\u20132005)","volume":"20","author":"Borchers A","year":"2006","unstructured":"Borchers A, Magdesian KG, Halland S, Pusterla N, Wilson WD. Successful treatment and polymerase chain reaction (PCR) confirmation of Tyzzer\u2019s disease in a foal and clinical and pathologic characteristics of 6 additional foals (1986\u20132005). J Vet Intern Med. 2006;20(5):1212\u20131218."},{"issue":"4","key":"ref25","series-title":"J Vet Intern Med","first-page":"1502","article-title":"Association between forage mycotoxins and liver disease in horses","volume":"36","author":"Durham AE","year":"2022","unstructured":"Durham AE. Association between forage mycotoxins and liver disease in horses. J Vet Intern Med. 2022;36(4):1502\u20131507.35792718"},{"key":"ref26","series-title":"Jubb, Kennedy, and Palmer\u2019s Pathology of Domestic Animals","first-page":"258","article-title":"Liver and biliary system","author":"Cullen JM","year":"2016","unstructured":"Cullen JM, Stalker MJ. Liver and biliary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer\u2019s Pathology of Domestic Animals. 6th ed. Elsevier Inc; 2016:258\u2013352."},{"issue":"11","key":"ref27","series-title":"Vet Sci","first-page":"282","article-title":"Molecular prevalence of equine parvovirus-hepatitis in the sera of clinically healthy horses in South Korea","volume":"8","author":"Lee SK","year":"2021","unstructured":"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;8(11):282. doi:10.3390\/vetsci811028234822655"},{"issue":"2","key":"ref28","series-title":"Equine Vet J","first-page":"379","article-title":"Active equine parvovirus-hepatitis infection is most frequently detected in Austrian horses of advanced age","volume":"54","author":"Badenhorst M","year":"2022","unstructured":"Badenhorst M, de Heus P, Auer A, Active equine parvovirus-hepatitis infection is most frequently detected in Austrian horses of advanced age. Equine Vet J. 2022;54(2):379\u2013389.33704819"},{"issue":"10","key":"ref29","series-title":"Viruses","first-page":"965","article-title":"Characterization of equine parvovirus in Thoroughbred breeding horses from Germany","volume":"11","author":"Meister TL","year":"2019","unstructured":"Meister TL, Tegtmeyer B, Br\u00fcggemann Y, Characterization of equine parvovirus in Thoroughbred breeding horses from Germany. Viruses. 2019;11(10):965. doi:10.3390\/v1110096531635426"},{"issue":"3","key":"ref30","series-title":"Hepatol Res","first-page":"263","article-title":"Clinicopathological features of acute-onset autoimmune hepatitis","volume":"25","author":"Okano N","year":"2003","unstructured":"Okano N, Yamamoto K, Sakaguchi K, Clinicopathological features of acute-onset autoimmune hepatitis. Hepatol Res. 2003;25(3):263\u2013270.12697247"},{"issue":"4","key":"ref31","series-title":"Hepatology","first-page":"545","article-title":"Mechanism of gamma-glutamyl transpeptidase release in serum during intrahepatic and extrahepatic cholestasis in the rat: a histochemical, biochemical and molecular approach","volume":"11","author":"Bulle F","year":"1990","unstructured":"Bulle F, Mavier P, Zafrani ES, Mechanism of gamma-glutamyl transpeptidase release in serum during intrahepatic and extrahepatic cholestasis in the rat: a histochemical, biochemical and molecular approach. Hepatology. 1990;11(4):545\u2013550."},{"issue":"1","key":"ref32","series-title":"Vet Clin North Am Equine Pract","first-page":"105","article-title":"Clinical pathology in the adult sick horse: the gastrointestinal system and liver","volume":"36","author":"DeNotta SL","year":"2020","unstructured":"DeNotta SL, Divers TJ. Clinical pathology in the adult sick horse: the gastrointestinal system and liver. Vet Clin North Am Equine Pract. 2020;36(1):105\u2013120.31982231"}],"container-title":["Journal of the American Veterinary Medical Association"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/261\/2\/javma.22.08.0368.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/261\/2\/javma.22.08.0368.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/261\/2\/javma.22.08.0368.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T12:59:28Z","timestamp":1741352368000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/261\/2\/javma.22.08.0368.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,1]]},"references-count":32,"journal-issue":{"issue":"2"},"URL":"https:\/\/doi.org\/10.2460\/javma.22.08.0368","relation":{},"ISSN":["0003-1488"],"issn-type":[{"value":"0003-1488","type":"print"}],"subject":[],"published":{"date-parts":[[2023,2,1]]}}}