Retracted: The prevalence of elevated gamma‐glutamyltransferase and sorbitol dehydrogenase activity in racing Thoroughbreds and their associations with viral infection

Abstract

Summary Background 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 these viruses may commonly infect racehorses and contribute to increased liver enzyme activity in this population. Objectives To investigate the association between viral infection and increased liver enzyme activity in racing Thoroughbreds. Study design Cross‐sectional study. Methods Prerace blood samples were collected from 802 Thoroughbreds and tested for GGT and sorbitol dehydrogenase (SDH) activity, and the presence of PgV E, HcV A, PgV D and EqPV‐H nucleic acid. Results Increased SDH and/or GGT were detected in 56.2% of the 802 serum samples. The infection prevalence and relative risk (RR) of having concurrently increased liver enzyme activity were: PgV E = 18.2% (RR = 0.820, 95% CI = 0.662–0.978, P = 0.03), HcV A = 2.5% (RR = 1.132, 95% CI = 0.719–1.466, P = 0.6), PgV D = 0.5% (RR = 0.875, 95% CI = 0.165–1.598, P>0.9), EqPV‐H = 2.9% (RR = 0.916, 95% CI = 0.564–1.266, P = 0.7). Main limitations Longitudinal samples were not tested. Conclusions While viral infection was common among Thoroughbreds in this study, infection did not explain the high prevalence of increased liver enzyme activity. In fact, PgV E infection was associated with a reduced risk of having increased liver enzyme activity, indicating PgV E is unlikely to be a cause of hepatitis in horses. Importantly, like GGT, increased SDH activity was highly prevalent in this study, and provides additional evidence that hepatocellular injury was occurring in these horses.

Tropism, pathology, and transmission of equine parvovirus-hepatitis

“…Equine parvovirus-hepatitis (EqPV-H) was first described in 2018 in a case of Theiler's disease, a form of acute hepatic necrosis [1]. In the United States, China, and Germany, EqPV-H has an estimated viremia prevalence of 2.9-17%, with 54% prevalence on farms where Theiler's disease was recently documented [1][2][3][4][5][6]. EqPV-H infection is closely linked to both Theiler's disease and subclinical hepatitis [2,7].…”

Clinical Pathology in the Adult Sick Horse

“…[37][38][39][40] Oxidative stress has been hypothesized as a cause. 28 The incidence of this increased GGT activity in racehorses in 1 study was 18%, 41 but in some stables it may be higher. This abnormality has not been proved to affect performance, although many trainers believe there is a correlation between the high GGT syndrome and reduced performance.…”

Metabolismo en rumiantes y su asociación con analitos bioquímicos sanguíneos

“…El torrente sanguíneo es el medio por el cual los nutrientes absorbidos se dirigen al hígado y a otros órganos para su catabolismo o anabolismo, según la necesidad celular (Goyal y Longo, 2015). Las enzimas juegan un papel muy importante en el metabolismo, ya que son proteínas catalizadoras de reacciones específicas (Jindal y Warshel 2017); sin ellas las reacciones biológicas serían muy lentas para la vida celular (Ramsay et al, 2019). Su función es unirse temporalmente a una molécula, parta aplicar cambios atómicos (Menger y Nome, 2019).…”