Identification of a Novel Hepacivirus in Domestic Cattle from Germany.

UNLABELLED: Hepatitis C virus (HCV) continues to represent one of the most significant threats to human health. In recent years, HCV-related sequences have been found in bats, rodents, horses, and dogs, indicating a widespread distribution of hepaciviruses among animals. By applying unbiased high-throughput sequencing, a novel virus of the genus Hepacivirus was discovered in a bovine serum sample. De novo assembly yielded a nearly full-length genome coding for a polyprotein of 2,779 amino acids. Phylogenetic analysis confirmed that the virus represents a novel species within the genus Hepacivirus. Viral RNA screening determined that 1.6% (n = 5) of 320 individual animals and 3.2% (n = 5) of 158 investigated cattle herds in Germany were positive for bovine hepacivirus. Repeated reverse transcription-PCR (RT-PCR) analyses of animals from one dairy herd proved that a substantial percentage of cows were infected, with some of them being viremic for over 6 months. Clinical and postmortem examination revealed no signs of disease, including liver damage. Interestingly, quantitative RT-PCR from different organs and tissues, together with the presence of an miR-122 binding site in the viral genome, strongly suggests a liver tropism for bovine hepacivirus, making this novel virus a promising animal model for HCV infections in humans. IMPORTANCE: Livestock animals act as important sources for emerging pathogens. In particular, their large herd size and the existence of multiple ways of direct and food-borne infection routes emphasize their role as virus reservoirs. Apart from the search for novel viruses, detailed characterization of these pathogens is indispensable in the context of risk analysis. Here, we describe the identification of a novel HCV-like virus in cattle. In addition, determination of the prevalence and of the course of infection in cattle herds provides valuable insights into the biology of this novel virus. The results presented here form a basis for future studies targeting viral pathogenesis of bovine hepaciviruses and their potential to establish zoonotic infections.

Comparison of isoflurane inhalation anaesthesia, injection anaesthesia and high volume caudal epidural anaesthesia for umbilical surgery in calves; metabolic, endocrine and cardiopulmonary effects.

OBJECTIVE: To compare three anaesthetic protocols for umbilical surgery in calves regarding adequacy of analgesia, and cardiopulmonary and hormonal responses. STUDY DESIGN: Prospective, randomised experimental study. ANIMALS: Thirty healthy German Holstein calves (7 female, 23 male) aged 45.9 ± 6.4 days. METHODS: All calves underwent umbilical surgery in dorsal recumbency. The anaesthetic protocols were as follows: group INH (n = 10), induction 0.1 mg kg(-1) xylazine IM and 2.0 mg kg(-1) ketamine IV, maintenance isoflurane in oxygen; Group INJ (n = 10), induction 0.2 mg kg(-1) xylazine IM and 5.0 mg kg(-1) ketamine IV, maintenance 2.5 mg kg(-1) ketamine IV every 15 minutes or as required; group EPI (n = 10), high volume caudal epidural anaesthesia with 0.2 mg kg(-1) xylazine diluted to 0.6 mL kg(-1) with procaine 2%. All calves received peri-umbilical infiltration of procaine and pre-operative IV flunixin (2.2 mg kg(-1) ). Cardiopulmonary variables were measured at preset intervals for up to 2 hours after surgery. The endocrine stress response was determined. Intra-operative nociception was assessed using a VAS scale. Data were compared between groups using appropriate statistical tests. A value of p < 0.05 was considered significant. RESULTS: All three protocols provided adequate anaesthesia for surgery although, as judged by the VAS scale, intra-operative response was greatest with INJ. Lowest mean cortisol levels during surgery occurred in EPI. Heart rate and cardiac output did not differ between groups, but mean arterial blood pressure, systemic vascular resistance, and partial pressure of carbon dioxide were higher and arterial pH lower in groups INH and INJ than in Group EPI. Group INJ became hypoxaemic and had a significantly greater vascular shunt than did the other groups. CONCLUSION AND CLINICAL RELEVANCE: Groups INH and EPI both proved acceptable protocols for calves undergoing umbilical surgery, whilst INJ resulted in variable anti-nociception and in hypoxaemia. High volume caudal epidural anaesthesia provides a practical inexpensive method of anaesthesia for umbilical surgery.

Effects of xylazine hydrochloride on hormonal, metabolic, and cardiorespiratory stress responses to lateral recumbency and claw trimming in dairy cows.

OBJECTIVE: To investigate the hormonal, metabolic, and cardiorespiratory effects of xylazine hydrochloride on dairy cows undergoing lateral recumbency and claw trimming. DESIGN: Prospective crossover study. ANIMALS: 6 healthy Holstein-Friesian cows. PROCEDURES: Cows were treated with xylazine (0.05 mg/kg [0.023 mg/lb], IM) or an equal volume of saline (0.9% NaCl) solution 15 minutes before being placed in lateral recumbency for claw trimming. As a third treatment, cows also received xylazine (0.05 mg/kg, IM) but underwent no further manipulation. At preset time intervals, heart rate (HR), respiratory rate (RR), systolic arterial blood pressure, diastolic arterial blood pressure, mean arterial blood pressure (MAP), blood gas values, and plasma concentrations of cortisol, insulin, glucose, lactate, and nonesterified fatty acids (NEFA) were measured, and signs of sedation and ruminal bloat were recorded. RESULTS: Saline solution treatment resulted in a temporary significant increase in SAP, diastolic arterial blood pressure, MAP, RR, and cortisol, lactate, and NEFA concentrations and a significant decrease in arterial oxygen saturation (Sao(2)). Xylazine treatment induced significant decreases in HR, RR, MAP, insulin and NEFA concentrations, and Sao(2) and induced significant increases in glucose concentration. Compared with saline solution treatment, HR, RR, MAP, Sao(2), and cortisol, lactate, and NEFA concentrations were significantly decreased with xylazine treatment. Xylazine treatment resulted in mild signs of sedation as well as clinically negligible ruminal bloat. CONCLUSIONS AND CLINICAL RELEVANCE: Xylazine administered in a low dose to cows preceding lateral recumbency for claw trimming decreased hormonal and metabolic stress responses, but augmented the respiratory depressive effect of lateral recumbency reflected by a decreased Pao and increased Paco(2).

The use of xylazine hydrochloride in an analgesic protocol for claw treatment of lame dairy cows in lateral recumbency on a surgical tipping table.

The objective of this study was to investigate the effect of xylazine on the stress and pain response of lame cows undergoing claw treatment in lateral recumbency (LR). Twenty-four lame, German Holstein-Friesian cows were included in a prospective, blinded, placebo-controlled clinical case study. Cows were randomly allocated to two groups (n=12) and either treated with xylazine (0.05 mg/kg BW, i.m.) or an equal volume of saline (controls) 15 min before placing them in LR. Before surgical treatment, each cow received retrograde intravenous local anaesthesia (LA). Over a period of 6h, heart rate (HR), respiratory rate (RR), plasma concentrations of cortisol, glucose, lactate and non-esterified fatty acids (NEFA) were determined at preset time intervals and the animals' behaviour was recorded via video recording and pedometer. All xylazine-treated cows showed signs of mild sedation, a reduced pain response on insertion of the needle for LA, reduced ear flicking during surgery, reduced lameness score and longer standing periods as well as improved appetite in the first hour postoperatively. Mean HR and RR, as well as plasma concentrations of NEFA were significantly reduced after xylazine treatment. Cortisol concentrations were significantly lower in xylazine-treated cows after being placed in LR but were similar to controls during surgery. The use of a low dose of xylazine in the analgesic protocol for the treatment of lame cows in LR alleviates stress and potentiates the analgesic effects of LA.