Hepatitis in horses refers to inflammation of the liver, which can arise from various causes including infectious agents, toxins, or immune-mediated processes. This condition affects the liver's ability to perform essential functions such as detoxification, metabolism, and protein synthesis. In horses, hepatitis can manifest in different forms, including acute and chronic, each with distinct clinical presentations and pathological findings. Diagnostic approaches often involve a combination of clinical evaluation, biochemical testing, imaging, and liver biopsy to determine the underlying cause and severity of the disease. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnostic methods, and management strategies for hepatitis in equine patients.
Zehetner V, Cavalleri JV, Klang A, Hofer M, Preining I, Steinborn R, Ramsauer AS.There is strong evidence that equine parvovirus-hepatitis (EqPV-H) is associated with the onset of Theiler's disease, an acute hepatic necrosis, in horses. However, the impact of this virus on other hepatopathies remains unknown. The objective of this retrospective study was to evaluate the prevalence and quantify the viral loads of EqPV-H in formalin-fixed, paraffin-embedded equine and donkey livers with various histopathologic abnormalities. The pathologies included cirrhosis, circulatory disorders of the liver, toxic and metabolic hepatic diseases as well as neoplastic and inflammatory dise...
Ellero N, Lanci A, Avallone G, Mariella J, Castagnetti C, Muscatello LV, Di Maio C, Freccero F.Seizures, coma and death rapidly appeared after admission in a one ‑month‑old foal with a history of lethargy, fever and anorexia. Severe icterus and necrotizing hepatitis were observed at necropsy. Clinical signs, laboratory and postmortem findings were compatible with a suspect of clostridial hepatitis. Tyzzer’s disease was confirmed by the presence of organisms morphologically consistent with Clostridium piliforme in the hepatocytes at the margins of multiple areas of hepatic necrosis. To the authors’ knowledge, this is the first reported case of clostridial hepatitis caused by Clos...
Reinecke B, Klöhn M, Brüggemann Y, Kinast V, Todt D, Stang A, Badenhorst M, Koeppel K, Guthrie A, Groner U, Puff C, de le Roi M, Baumgärtner W....Since its first discovery by Arnold Theiler in 1918, serum hepatitis also known as Theiler's disease has been reported worldwide, causing idiopathic acute hepatitis and liver failure in horses. Recent studies have suggested a novel parvovirus, named equine parvovirus hepatitis (EqPV-H), to be associated with Theiler's disease. Despite the severity and potential fatality of EqPV-H infection, little is known about the possibility of developing chronic infections and putative cross-species infection of equine sister species. In the present longitudinal study, we employed qPCR analysis, serology, ...
de Moraes MVDS, Salgado CRS, Godoi TLOS, de Almeida FQ, Chalhoub FLL, de Filippis AMB, de Souza AM, de Oliveira JM, Figueiredo AS.The equine parvovirus-hepatitis (EqPV-H), recently identified in association with serum hepatitis in horses (also known as Theiler's disease), has been so far described in horses from North America, Asia and Europe. There is no information regarding its circulation in South America. Our retrospective study (2013-2016) screened by EqPV-H nested-PCR a total of 96 Brazilian horses grouped according to previous status of infection: Known to be positive for one or more horse "hepatitis viruses" (equine hepacivirus, equine pegivirus-EPgV and Theiler's disease-associated virus) and known to be negati...
García JA, Navarro MA, Fresneda K, Uzal FA.Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and...
Ramsauer AS, Badenhorst M, Cavalleri JV.Equine parvovirus hepatitis (EqPV-H) was first described in 2018 in a fatal case of Theiler's disease which followed the administration of an equine-origin biological product. The virus has since been frequently identified in serum and liver tissue of horses affected by Theiler's disease-an acute, severe hepatitis characterised by fulminant hepatic necrosis with a fatal outcome in most cases. EqPV-H is hepatotropic, appears to be associated with subclinical to severe hepatitis in horses, and is a likely cause of Theiler's disease. Although this disease is most frequently reported following the...
Hui A, Altan E, Slovis N, Fletcher C, Deng X, Delwart E.Circoviruses infect vertebrates where they can result in a wide range of disease signs or in asymptomatic infections. Using viral metagenomics we analyzed a pool of five sera from four healthy and one sick horse. Sequences from parvovirus-H, equus anellovirus, and distantly related to mammalian circoviruses were recognized. PCR identified the circovirus reads as originating from a pregnant mare with fever and hepatitis. That horse's serum was also positive by real time PCR for equine parvovirus H and negative for the flavivirus equine hepacivirus. The complete circular genome of equine circovi...
Badenhorst M, de Heus P, Auer A, Tegtmeyer B, Stang A, Dimmel K, Tichy A, Kubacki J, Bachofen C, Steinmann E, Cavalleri JMV.Equine parvovirus-hepatitis (EqPV-H) research is in its infancy. Information regarding prevalence, geographical distribution, genetic diversity, pathogenesis and risk factors enhances understanding of this potentially fatal infection. Objective: Determining the prevalence of EqPV-H in Austrian equids. Investigating factors increasing probability of infection, liver-associated biochemistry parameters, concurrent equine hepacivirus (EqHV) infection and phylogenetic analysis of Austrian EqPV-H variants. Methods: Cross-sectional study. Methods: Sera from 259 horses and 13 donkeys in Austria were a...
Rasche A, Lehmann F, Goldmann N, Nagel M, Moreira-Soto A, Nobach D, de Oliveira Carneiro I, Osterrieder N, Greenwood AD, Steinmann E, Lukashev AN....Preclinical testing of novel therapeutics for chronic hepatitis B (CHB) requires suitable animal models. Equids host homologs of hepatitis C virus (HCV). Because coinfections of hepatitis B virus (HBV) and HCV occur in humans, we screened 2,917 specimens from equids from five continents for HBV. We discovered a distinct HBV species (Equid HBV, EqHBV) in 3.2% of donkeys and zebras by PCR and antibodies against EqHBV in 5.4% of donkeys and zebras. Molecular, histopathological, and biochemical analyses revealed that infection patterns of EqHBV resembled those of HBV in humans, including hepatotro...
Mann S, Ramsay JD, Wakshlag JJ, Stokol T, Reed S, Divers TJ.High-serum γ-Glutamyl Transferase (GGT) activity has been associated with and thought to be a marker of maladaptation to training and possibly poor performance in racehorses, but the cause is unknown. Objective: To investigate possible metabolic and infectious causes for the high GGT syndrome. Methods: Pilot case-control study and nested case-control study. Methods: The case-control study in 2017 included 16 horses (8 cases and 8 controls with median [range] serum GGT 82 [74-148] and 22 [19-28] IU/L, respectively) from the same stable. In 2018, similar testing was performed in a nested case-...
Tomlinson JE, Wolfisberg R, Fahnøe U, Sharma H, Renshaw RW, Nielsen L, Nishiuchi E, Holm C, Dubovi E, Rosenberg BR, Tennant BC, Bukh J, Kapoor A....Pegiviruses frequently cause persistent infection (as defined by >6 months), but unlike most other Flaviviridae members, no apparent clinical disease. Human pegivirus (HPgV, previously GBV-C) is detectable in 1-4% of healthy individuals and another 5-13% are seropositive. Some evidence for infection of bone marrow and spleen exists. Equine pegivirus 1 (EPgV-1) is not linked to disease, whereas another pegivirus, Theiler's disease-associated virus (TDAV), was identified in an outbreak of acute serum hepatitis (Theiler's disease) in horses. Although no subsequent reports link TDAV to disease, an...
Vengust M, Jager MC, Zalig V, Cociancich V, Laverack M, Renshaw RW, Dubovi E, Tomlinson JE, Van de Walle GR, Divers TJ.Equine parvovirus-hepatitis (EqPV-H) has been proposed as the aetiological cause of Theiler's disease, also known as serum hepatitis. EqPV-H-associated Theiler's disease has not been previously reported in Europe. Objective: To determine whether EqPV-H infection was associated with a 2018-2019 outbreak of Theiler's disease in four horses on a studfarm. Methods: Descriptive case series. Methods: The medical records of four horses from the same farm diagnosed with fatal Theiler's disease were examined retrospectively. Information collected included a clinical history, physical examination findin...
Tomlinson JE, Jager M, Struzyna A, Laverack M, Fortier LA, Dubovi E, Foil LD, Burbelo PD, Divers TJ, Van de Walle GR.Equine parvovirus-hepatitis (EqPV-H) has recently been associated with cases of Theiler's disease, a form of fulminant hepatic necrosis in horses. To assess whether EqPV-H is the cause of Theiler's disease, we first demonstrated hepatotropism by PCR on tissues from acutely infected horses. We then experimentally inoculated horses with EqPV-H and 8 of 10 horses developed hepatitis. One horse showed clinical signs of liver failure. The onset of hepatitis was temporally associated with seroconversion and a decline in viremia. Liver histology and in situ hybridization showed lymphocytic infiltrate...
Lu G, Wu L, Ou J, Li S.Equine parvovirus-hepatitis (EqPV-H) was first reported in a horse that died of equine serum hepatitis in the USA in 2018, and was determined having a strong association with equine serum hepatitis in the following studies. As a newly discovered virus, the genomic sequences of only seven EqPV-H strains have been reported. Considering this, an epidemiological study was performed to investigate the prevalence of EqPV-H in equines in Guangdong Province in China, and obtain genomic sequences of the field prevalent EqPV-H strains. The detection rate of EqPV-H was finally determined to be 8.33% (95%...
Baird J, Tegtmeyer B, Arroyo L, Stang A, Brüggemann Y, Hazlett M, Steinmann E.Theiler's disease was confirmed within a group horses located on a farm in southwestern Ontario during the summer and autumn of 2005. Five sudden deaths occurred between 3 July and 21 August, 2005, none of which were necropsied, however two of the horses showed clinical signs compatible with hepatic encephalopathy prior to death. No horse on the farm had received a biologic product of equine blood origin in the preceding six months. The only biologics used on the property were the administration of killed vaccines for rabies, tetanus and West Nile Virus to all horses 30 days prior to the onset...
Rui P, Zhao F, Yan S, Wang C, Fu Q, Hao J, Zhou X, Zhong H, Tang M, Hui W, Li W, Shi D, Ma Z, Song T.Hepatitis E virus (HEV) is the causative agent of acute self-limiting hepatitis in humans in developing countries. Hepatitis E virus RNA was first detected in donkeys in Spain, but little is known about the possible presence of HEV in donkeys in China. Objective: To investigate the prevalence of HEV in donkeys in northern China. Methods: Investigation of the prevalence of HEV in donkeys using serological, molecular and phylogenetic approaches. Methods: A total of 401 donkey serum specimens were tested for serological and molecular detection of HEV via enzyme-linked immunosorbent assay and quan...
Meister TL, Tegtmeyer B, Brüggemann Y, Sieme H, Feige K, Todt D, Stang A, Cavalleri JV, Steinmann E.An equine parvovirus-hepatitis (EqPV-H) has been recently identified in association with equine serum hepatitis, also known as Theiler's disease. The disease was first described by Arnold Theiler in 1918 and is often observed with parenteral use of blood products in equines. However, natural ways of viral circulation and potential risk factors for transmission still remain unknown. In this study, we investigated the occurrence of EqPV-H infections in Thoroughbred horses in northern and western Germany and aimed to identify potential risk factors associated with viral infections. A total of 392...
Tegtmeyer B, Echelmeyer J, Pfankuche VM, Puff C, Todt D, Fischer N, Durham A, Feige K, Baumgärtner W, Steinmann E, Cavalleri JV.Equine hepacivirus (EqHV) in equids represents the closest homologue to hepatitis C virus (HCV) infecting humans. A majority of HCV infected patients develop a chronic course of infection leading to liver fibrosis, cirrhosis and liver failure. However, in horses mostly transient mild subclinical infections are reported for EqHV to date. EqHV can be involved in chronic liver diseases of horses. Biochemical parameters in serum samples were measured. Viral load was determined using qPCR. Next generation sequencing (NGS) of serum was performed. Liver tissue was stained with haematoxylin and eosin ...
Meister TL, Tegtmeyer B, Postel A, Cavalleri JV, Todt D, Stang A, Steinmann E.An equine parvovirus-hepatitis (EqPV-H) has been recently identified in association with equine serum hepatitis, also known as Theiler's disease. This disease was first described by Arnold Theiler in 1918 and is often observed after applications with blood products in equines. So far, the virus has only been described in the USA and China. In this study, we evaluated the presence of EqPV-H in several commercial serum samples to assess the potential risk of virus transmission by equine serum-based products for medical and research applications. In 11 out of 18 commercial serum samples, EqPV-H D...
Tomlinson JE, Van de Walle GR, Divers TJ.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 th...
Ramsay JD, Evanoff R, Mealey RH, Simpson EL.In racehorses, serum gamma-glutamyltransferase (GGT) activity is positively correlated with cumulative days in training and, when ≥100 IU/L, has been associated with poor performance. The prevalence of increased GGT activity in North American Thoroughbreds and its aetiopathogenesis are unknown. Four emerging viruses, pegivirus E (PgV E; equine pegivirus), hepacivirus A (HcV A; equine hepacivirus), pegivirus D (PgV D; Theiler's disease virus), and equine parvovirus-hepatitis (EqPV-H) have been identified in horses with clinical and subclinical hepatopathy. Available prevalence data indicate ...
Tirosh-Levy S, Perl S, Valentine BA, Kelmer G.Hepatoblastoma was diagnosed in a 3-year-old Thoroughbred gelding presented with forelimb lameness with bilateral fatigue fractures of the proximal third metacarpal bones. An abdominal mass was detected on ultrasound examination of the abdomen. Absolute erythrocytosis was diagnosed after clinical and haematological evaluation. The fractured metacarpal bones were surgically removed but complications after surgery were fatal. The liver mass was diagnosed as a hepatoblastoma based on histology and immunochemical staining. The combination of hepatoblastoma and fatigue fractures has not been descri...
Tomlinson JE, Tennant BC, Struzyna A, Mrad D, Browne N, Whelchel D, Johnson PJ, Jamieson C, Löhr CV, Bildfell R, McKenzie EC, Laverack M, Renshaw RW....A novel equine parvovirus (EqPV-H) was recently discovered in the equine liver with Theiler's disease. Objective: To determine the prevalence of EqPV-H infection in naturally occurring Theiler's disease cases and in-contact horses in the absence of historical equine biologic product administration. Methods: Ten cases of Theiler's disease from 6 separate properties were included in the study, based on the criteria of acute onset of clinical signs of liver failure with laboratory or histopathologic findings characteristic of Theiler's disease and no history of receiving an equine biologic produc...
Tomlinson JE, Kapoor A, Kumar A, Tennant BC, Laverack MA, Beard L, Delph K, Davis E, Schott Ii H, Lascola K, Holbrook TC, Johnson P, Taylor SD....Three flaviviruses (equine pegivirus [EPgV]; Theiler's disease-associated virus [TDAV]; non-primate hepacivirus [NPHV]) and equine parvovirus (EqPV-H) are present in equine blood products; the TDAV, NPHV, and EqPV-H have been suggested as potential causes of serum hepatitis. Objective: To determine the prevalence of these viruses in horses with equine serum hepatitis. Methods: Eighteen horses diagnosed with serum hepatitis, enrolled from US referral hospitals. Methods: In the prospective case study, liver, serum, or both samples were tested for EPgV, TDAV, NPHV, and EqPV-H by PCR. Results: Bot...
Theelen MJP, Beukers M, Grinwis GCM, Sloet van Oldruitenborgh-Oosterbaan MM.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...
Lu G, Sun L, Ou J, Xu H, Wu L, Li S.A novel equine parvovirus, equine parvovirus-hepatitis (EqPV-H), was first discovered in a horse that died of equine serum hepatitis in the USA in 2018. EqPV-H was shown to be a novel etiological agent associated with equine serum hepatitis. Following this initial report, no additional studies on EqPV-H have been published. In this study, a total of 143 serum samples were collected from racehorses at 5 separate farms in China and were analyzed to detect EqPV-H DNA via nested PCR. The results indicated a high prevalence of EqPV-H (11.9%, 17/143) in the studied animals. In addition, a remarkably...
García-Bocanegra I, Rivero A, Caballero-Gómez J, López-López P, Cano-Terriza D, Frías M, Jiménez-Ruiz S, Risalde MA, Gómez-Villamandos JC....Hepatitis E (HE) is an important emerging disease in European countries. To analyse the role of equids as potential reservoirs for HE virus (HEV), we determined the prevalence of HEV infection in 861 equines from 464 herds in Spain. HEV RNA in serum was detected in 0.4% (3/692) of horses, 1.2% (1/86) of donkeys and 3.6% (3/83) of mules. Phylogenetic analysis identified the zoonotic genotype 3 as being closely related to viral human and swine strains. In this first report on HEV in equids in Europe, we confirm the susceptibility of horses, donkeys and mules to HEV infection. The low prevalence ...
Badenhorst M, Tegtmeyer B, Todt D, Guthrie A, Feige K, Campe A, Steinmann E, Cavalleri JMV.Since the discovery of equine hepacivirus (EqHV) in 2011, the virus has been detected in horse populations from more than twelve countries across five continents. EqHV seroprevalence has been reported to be as high as 61.8% and EqHV ribonucleic acid (RNA) prevalence to range between 0.9% and 34.1%. Molecular and serological indications of EqHV infection have never been reported in equids on the African continent. Therefore, investigation of EqHV prevalence in South African horses and subsequent viral genetic characterization contribute to a better understanding of the global epidemiology of th...
Forni D, Cagliani R, Pontremoli C, Pozzoli U, Vertemara J, De Gioia L, Clerici M, Sironi M.Hepatitis C virus (HCV) belongs to the genus and is genetically heterogeneous, with seven major genotypes further divided into several recognized subtypes. HCV origin was previously dated in a range between ∼200 and 1000 years ago. Hepaciviruses have been identified in several domestic and wild mammals, the largest viral diversity being observed in bats and rodents. The closest relatives of HCV were found in horses/donkeys (equine hepaciviruses, EHV). However, the origin of HCV as a human pathogen is still an unsolved puzzle. Using a selection-informed evolutionary model, we show that the c...
Moeller RB, Crossley B, Pipkin A, Li Y, Balasuriya UBR.A 2-y-old female Grant's zebra ( Equus quagga [ burchellii] boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear ...
Baird J, Tegtmeyer B, Arroyo L, Stang A, Brüggemann Y, Hazlett M, Steinmann E.Theiler's disease was confirmed within a group horses located on a farm in southwestern Ontario during the summer and autumn of 2005. Five sudden deaths occurred between 3 July and 21 August, 2005, none of which were necropsied, however two of the horses showed clinical signs compatible with hepatic encephalopathy prior to death. No horse on the farm had received a biologic product of equine blood origin in the preceding six months. The only biologics used on the property were the administration of killed vaccines for rabies, tetanus and West Nile Virus to all horses 30 days prior to the onset...
Aleman M, Nieto JE, Carr EA, Carlson GP.This report describes 4 fatal cases of serum hepatitis associated with the administration of commercial plasma in the horse. Serum hepatitis in the horse is characterized by acute hepatic central lobular necrosis, and it has been associated with the administration of biological products of equine origin. None of these horses had a recent history of equine biologic-origin vaccination; however, they had received 1.5-5 L of commercial plasma, and in I horse, an additional 8 L of fresh blood. Acute, severe colic unresponsive to medical therapy, lethargy, or sudden death developed in these 4 horses...
Tsachev I, Gospodinova K, Pepovich R, Takova K, Kundurzhiev T, Zahmanova G, Kaneva K, Baymakova M.In recent years, hepatitis E virus (HEV) infection has been found to be widespread among different animal species worldwide. In Bulgaria, high HEV seropositivity was found among pigs (60.3%), wild boars (40.8%), and East Balkan swine (82.5%). The aim of the present study was to establish the seroprevalence of HEV among dogs, cats, horses, cattle, sheep, and goats in Bulgaria. In total, 720 serum samples from six animal species were randomly collected: dogs-90 samples; cats-90; horses-180; cattle-180; sheep-90; and goats-90. The serum samples were collected from seven districts of the country: ...
Mann S, Ramsay JD, Wakshlag JJ, Stokol T, Reed S, Divers TJ.High-serum γ-Glutamyl Transferase (GGT) activity has been associated with and thought to be a marker of maladaptation to training and possibly poor performance in racehorses, but the cause is unknown. Objective: To investigate possible metabolic and infectious causes for the high GGT syndrome. Methods: Pilot case-control study and nested case-control study. Methods: The case-control study in 2017 included 16 horses (8 cases and 8 controls with median [range] serum GGT 82 [74-148] and 22 [19-28] IU/L, respectively) from the same stable. In 2018, similar testing was performed in a nested case-...
Forni D, Cagliani R, Pontremoli C, Pozzoli U, Vertemara J, De Gioia L, Clerici M, Sironi M.Hepatitis C virus (HCV) belongs to the genus and is genetically heterogeneous, with seven major genotypes further divided into several recognized subtypes. HCV origin was previously dated in a range between ∼200 and 1000 years ago. Hepaciviruses have been identified in several domestic and wild mammals, the largest viral diversity being observed in bats and rodents. The closest relatives of HCV were found in horses/donkeys (equine hepaciviruses, EHV). However, the origin of HCV as a human pathogen is still an unsolved puzzle. Using a selection-informed evolutionary model, we show that the c...
Hui A, Altan E, Slovis N, Fletcher C, Deng X, Delwart E.Circoviruses infect vertebrates where they can result in a wide range of disease signs or in asymptomatic infections. Using viral metagenomics we analyzed a pool of five sera from four healthy and one sick horse. Sequences from parvovirus-H, equus anellovirus, and distantly related to mammalian circoviruses were recognized. PCR identified the circovirus reads as originating from a pregnant mare with fever and hepatitis. That horse's serum was also positive by real time PCR for equine parvovirus H and negative for the flavivirus equine hepacivirus. The complete circular genome of equine circovi...
Guglick MA, MacAllister CG, Ely RW, Edwards WC.Seven horses developed clinical or subclinical hepatitis 48 to 87 days after administration of tetanus antitoxin. One horse had mildly high hepatic enzyme activity 120 days after inoculation with tetanus antitoxin. The first horse developed signs of depression, lethargy, and anorexia. During hospitalization, signs of hepatoencephalopathy were noticed, and laboratory data were consistent with hepatic disease. Another horse that was found dead had gross and histologic lesions compatible with serum hepatitis. Screening of serum gamma-glutamyltransferase (GGT) and aspartate transaminase activities...
Rui P, Zhao F, Yan S, Wang C, Fu Q, Hao J, Zhou X, Zhong H, Tang M, Hui W, Li W, Shi D, Ma Z, Song T.Hepatitis E virus (HEV) is the causative agent of acute self-limiting hepatitis in humans in developing countries. Hepatitis E virus RNA was first detected in donkeys in Spain, but little is known about the possible presence of HEV in donkeys in China. Objective: To investigate the prevalence of HEV in donkeys in northern China. Methods: Investigation of the prevalence of HEV in donkeys using serological, molecular and phylogenetic approaches. Methods: A total of 401 donkey serum specimens were tested for serological and molecular detection of HEV via enzyme-linked immunosorbent assay and quan...
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.Equine parvovirus-hepatitis (EqPV-H) and equine hepacivirus (EqHV) are etiologically associated with Theiler's disease (TD), causing fulminant equine hepatitis, but the transmission route and co-infection effect remain unclear. We determined EqPV-H and EqHV prevalence and coinfection rate in 160 serum and 114 faecal samples using nested polymerase chain reaction. Amino acid and nucleotide analyses were performed and phylogenetic trees were constructed. By measuring liver-specific parameters (AST, GGT, TBIL and A/G ratio), hepatopathological changes in viremia status were compared. We found a h...
Theelen MJP, Beukers M, Grinwis GCM, Sloet van Oldruitenborgh-Oosterbaan MM.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...
Badenhorst M, Tegtmeyer B, Todt D, Guthrie A, Feige K, Campe A, Steinmann E, Cavalleri JMV.Since the discovery of equine hepacivirus (EqHV) in 2011, the virus has been detected in horse populations from more than twelve countries across five continents. EqHV seroprevalence has been reported to be as high as 61.8% and EqHV ribonucleic acid (RNA) prevalence to range between 0.9% and 34.1%. Molecular and serological indications of EqHV infection have never been reported in equids on the African continent. Therefore, investigation of EqHV prevalence in South African horses and subsequent viral genetic characterization contribute to a better understanding of the global epidemiology of th...
de Moraes MVDS, Salgado CRS, Godoi TLOS, de Almeida FQ, Chalhoub FLL, de Filippis AMB, de Souza AM, de Oliveira JM, Figueiredo AS.The equine parvovirus-hepatitis (EqPV-H), recently identified in association with serum hepatitis in horses (also known as Theiler's disease), has been so far described in horses from North America, Asia and Europe. There is no information regarding its circulation in South America. Our retrospective study (2013-2016) screened by EqPV-H nested-PCR a total of 96 Brazilian horses grouped according to previous status of infection: Known to be positive for one or more horse "hepatitis viruses" (equine hepacivirus, equine pegivirus-EPgV and Theiler's disease-associated virus) and known to be negati...
Swerczek TW.Reports of 148 cases of Tyzzer's disease in foals in central Kentucky were analyzed to identify features of the disease and factors associated with it. The records indicate that Tyzzer's disease is a rapidly progressive, highly fatal hepatitis caused by Clostridium piliforme. Common clinical findings are lethargy, fever, anorexia, and icterus. Seizures, coma, and death may rapidly ensue. Laboratory findings are leukopenia, metabolic acidosis, hypoglycemia, and increased activity of hepatic enzymes. Diagnosis is primarily based on clinical signs and postmortem findings but a polymerase chain re...
Findlay GM, Maccallum FO.(1) Among 3,100 persons immunized against yellow fever with virus and immune serum over a period of five years, 89 cases of jaundice have been traced.(2) The symptoms are those of a hepatitis and closely resemble those produced by common infective hepatic jaundice, cases of which have frequently been noted as occurring in the same areas.(3) The average period between the time of inoculation and the development of hepatitis is between two and three months.(4) Attention is directed to the occurrence of hepatitis in horses, usually two to three months after immunization against the viruses of hor...
Reinecke B, Klöhn M, Brüggemann Y, Kinast V, Todt D, Stang A, Badenhorst M, Koeppel K, Guthrie A, Groner U, Puff C, de le Roi M, Baumgärtner W....Since its first discovery by Arnold Theiler in 1918, serum hepatitis also known as Theiler's disease has been reported worldwide, causing idiopathic acute hepatitis and liver failure in horses. Recent studies have suggested a novel parvovirus, named equine parvovirus hepatitis (EqPV-H), to be associated with Theiler's disease. Despite the severity and potential fatality of EqPV-H infection, little is known about the possibility of developing chronic infections and putative cross-species infection of equine sister species. In the present longitudinal study, we employed qPCR analysis, serology, ...
Messer NT, Johnson PJ.Acute hepatic disease was diagnosed in 16 horses during the study period. Twelve of those cases were characterized as idiopathic acute hepatic disease (IAHD). In 9 of the 12 (75%) cases of IAHD, the horses were female, and 7 of the 9 females were lactating and had been treated with tetanus antitoxin at parturition. Diagnosis of IAHD was based on anamnesis, clinical signs, and results of serum biochemical analyses, hepatic biopsy, and postmortem examination. Within 1 year of the illness, 75% (9/12) of the horses had died or had been euthanatized. Not all horses had the typical fulminant signs a...
Hess S, Gulati R, Peluso JJ.The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To a...
McGorum BC, Murphy D, Love S, Milne EM.The clinicopathological features of 50 cases of equine hepatic disease were reviewed. There was a wide range of clinical signs and at least 50 per cent of the animals exhibited either dull demeanour, anorexia, abdominal pain, cerebral dysfunction and/or weight loss. Life-threatening complications of hepatic failure recorded were: gastric impaction in 10 cases, bilateral laryngeal paralysis in seven cases and coagulopathy in five cases. All the cases had high activities of gamma-glutamyl transferase (GGT) and most had high activities of glutamate dehydrogenase (GLDH) and high concentrations of ...
García JA, Navarro MA, Fresneda K, Uzal FA.Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and...
Yoon J, Park T, Sohn Y, Lee SK, Park BJ, Ahn HS, Go HJ, Kim DH, Lee JB, Park SY, Song CS, Lee SW, Choi IS.Hepatitis E virus (HEV) is an emerging zoonotic pathogen causing hepatitis worldwide. Despite the prevalent evidence of interspecies HEV infection in various animal species, the role of horses in HEV epidemiology remains unclear. In this study, we investigated the prevalence of HEV infection in 283 blood and 114 fecal samples from 397 horses using sandwich enzyme-linked immunosorbent assay and nested reverse transcription-polymerase chain reaction. Among the 283 serum samples, 35 were positive for anti-HEV antibodies (12.4%; 95% confidence interval: 8.8-16.8), and four of the five sampling reg...
Slocombe RF, Slauson DO.Invasive pulmonary aspergillosis was identified in 19 horses. In 16 cases mycotic lesions were associated with enterocolitis; 14 cases appeared to result from Salmonella infection. Pulmonary lesions included multifocal areas of acute necrosis, leukocytoclastic vasculitis, and thrombosis with fibrinosuppurative inflammation surrounding mycelial masses. Thromboemboli with fungi were in the brain and kidneys of three cases. Factors which appeared to predispose to pulmonary aspergillosis included corticosteroid therapy, disseminated neoplasms, hepatitis, pleuritis, and peritonitis. This study sugg...
Davis JL, Blikslager AT, Catto K, Jones SL.The purpose of this study was to test the hypothesis that horses with proximal enteritis (PE) are predisposed to hepatic injury. We also determined whether the presence of liver injury in horses with PE was associated with other clinicopathologic abnormalities or affected outcome. The medical records of all horses admitted for evaluation of colic and gastric reflux between 1984 and 2002 were reviewed. Horses were considered to have PE if the diagnosis was made at surgery or postmortem examination or if they had clinical findings consistent with PE. Horses with a small intestinal strangulating ...
Acland HM, Gunson DE, Gillette DM.Seven foals aged 18 days to 3 1/2 months had either single or multiple full-circumference segments or long antimesenteric bands of necrotizing duodenitis, sharply delineated from adjacent viable duodenum. Perforation of the necrotic wall had occurred in all foals, leading to acute fibrinous peritonitis. On the mucosal surface severe diffuse, acute inflammation and ulceration involved the anterior half of the duodenum. Two further foals, aged 28 and 30 days, had lesions that are believed to be a chronic form of this disease. Both foals had a thickened duodenal wall, with large areas of mucosa r...
Borchers A, Magdesian KG, Halland S, Pusterla N, Wilson WD.Tyzzer's disease is a rapidly progressive and highly fatal hepatitis of foals caused by Clostridium piliforme. Survival of a confirmed case has not been reported previously. Objective: Successful therapy of C. piliforme infection in foals is possible. Polymerase chain reaction (PCR) can be used to diagnose Tyzzer's disease antemortem or postmortem. Methods: Seven foals were included in the study. Methods: Retrospective study was made to evaluate the clinical and pathologic characteristics of foals with Tyzzer's disease. Medical records of the Veterinary Medical Teaching Hospital at University ...
Beeler-Marfisi J, Arroyo L, Caswell JL, Delay J, Bienzle D.Hepatoblastoma (HB) is an uncommon pediatric liver tumor in humans and horses. In humans, HB is most frequently diagnosed in fetuses, neonates, and young children, whereas hepatocellular carcinoma (HCC) affects juvenile and adult humans. Hepatoblastoma in the horse is rare, with only 9 reported cases. Affected horses ranged in age from late-term aborted fetuses to 3 years. The current study describes 3 new cases of primary liver tumors in horses and reviews findings in relation to other reports on this condition. Tumors classified as HB were identified in a male Standardbred aborted fetus and ...
Messer NT, Johnson PJ.Two adult Quarter Horse mares from the same farm developed signs of hepatic disease approximately 2 months after parturition. Both mares had received tetanus antitoxin at the time of foaling. One mare developed subcutaneous edema of the distal aspect of all 4 limbs, photodermatitis involving unpigmented areas of skin, and high serum activities of liver-specific enzymes. The other mare had signs of acute hepatic failure, including icterus, hepatic encephalopathy, and high serum activities of liver-specific enzymes, and died. The second mare had signs typical of serum hepatitis (Theiler's diseas...
Peek SF, Divers TJ.The medical approach to treatment of cholangiohepatitis and cholelithiasis in 9 horses is described. Seven horses were treated successfully and returned to normal use, with a minimum follow-up period of 12 months. Long-term antimicrobial therapy was believed to be critical in those cases that survived, with a median treatment duration of 51 days (range 17-124 days). Treatment failure was associated with severe periportal and bridging hepatic fibrosis from biopsy material obtained at admission in 2 horses, one of whom also presented with hyperammonaemic hepatic encephalopathy. Transabdominal ul...
