Veterinary Archives, Vol. 90 No. 6, 2020.
Original scientific paper
https://doi.org/10.24099/vet.arhiv.0790
Anti-GnRH vaccination of stallions shedding equine arteritis virus in their semen: a field study
Fabien Miszczak
; LABÉO Frank Duncombe (Normandy analysis and research centre) Saint-Contest, France; UNICAEN (Normandy University), Virology service, CHU Caen (Hospital), France
Dominik Burger
; Swiss Institute of Equine Medicine ISME, University of Berne, and Agroscope, Avenches, Switzerland
Bénédicte Ferry
; IFCE (French Institute of Horse and Riding), Saumur, France
Loïc Legrand
; LABÉO Frank Duncombe (Normandy analysis and research centre) Saint-Contest, France; Normandie Univ (Normandy University), UNICAEN, BIOTARGEN EA7450, Saint-Contest, France
Guillaume Fortier
; LABÉO Frank Duncombe (Normandy analysis and research centre) Saint-Contest, France; Normandie Univ (Normandy University), UNICAEN, BIOTARGEN EA7450, Saint-Contest, France
Anne-Lyse Laine
; INRAE, CNRS, Université de Tours (National Research Institute for Agriculture, Food and Environment, National Center for Scientific Research, Tours University), UMR PRC, Nouzilly, France
Astrid Vabret
; UNICAEN (Normandy University), Virology service, CHU Caen (Hospital), France
Stéphane Pronost
; LABÉO Frank Duncombe (Normandy analysis and research centre) Saint-Contest, France; Normandie Univ (Normandy University), UNICAEN, BIOTARGEN EA7450, Saint-Contest, France
Marianne Vidament
; IFCE (French Institute of Horse and Riding), Saumur, France; INRAE, CNRS, Université de Tours (National Research Institute for Agriculture, Food and Environment, National Center for Scientific Research, Tours University), UMR PRC, Nouzilly, France
Abstract
Stallions are natural reservoirs of equine arteritis virus (EAV) in their semen, representing a potential source of outbreaks. The carrier-state is testosterone-dependent, and clears spontaneously in 4 to 40% stallions. Reduction of testosterone secretion may be obtained with the anti-GnRH vaccine Equity. In this report, 16 naturally infected stallions excreting EAV in their semen were vaccinated twice with the vaccine EquityTM and monitored irregularly under field conditions for EAV viral load in their semen and plasmatic testosterone concentration. The results are indicated in months (M) after the first vaccine injection. Testosterone concentrations decreased from 1.7 to 0.2 ng/mL (P<0.002) after 3M. The EAV viral load decreased from 3.2×109 to 1.1×106 RNA copy/mL of semen (P<0.001) after 5M. One stallion died at 7M for other reason. At M3-10, 12/15 stallions ceased to shed the virus in their semen. At M5- 10, 9/15 stallions had plasmatic testosterone concentrations of ≥ 0.5 ng/mL but the 6 others showed a persistently low testosterone concentration (≤0.3 ng/mL). Of the 14 stallions that were expected to recover their reproductive activity at the time of the next breeding season (
Keywords
stallion; equine arteritis virus; anti-GnRH immunization; viral load; testosterone
Hrčak ID:
250263
URI
Publication date:
22.12.2020.
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