Equine herpesvirus type 1 (EHV-1) infection and vaccination with an inactivated EHV-1 vaccine

Abstract

Abstract Extract Madam:- We have been investigating episodes of severe respiratory disease in foals during their first year of life in the Waikato district of New Zealand. Most foals are affected at six to ten weeks of age and again at weaning time (4) Horner, G.W., Hunter, R., O'Flaherty, J.D. and Dickinson, L.G. 1976. Isolation of equine herpesviruses from horses with respiratory disease. N.Z. vet. J., 24: 171–176. [Taylor & Francis Online] , [Google Scholar] and the problem has been especially severe on one stud, ten foals having died of respiratory disease there in the past four years. Preliminary investigations on this stud have indicated that equine herpesviruse type 1 (EHV-1) and type 2 (EHV-2) were frequently isolated and might be the initiators of the respiratory disease observed. (5) Jolly, P.D. 1983. The development of an enzyme linked immunosorbent assayfor the detection of antibodies to equid herpesvirus type 1 in horsesera, Palemerston North: Massey University. B. Phil, thesis [Google Scholar] As part of an attempt to control this problem, an inactivated vaccine * *Pneumabort-K, Fort Dodge Laboratories, Iowa, U.S.A. derived from EHV-1 abortifacient strain (1) Bryans, J.T. 1978. Immunizaton of pregnant mares with an inactivated equine herpesvirus 1 vaccine. Proc 4th. Int. Conf. Equine Infec. Dis., Lyon, 1976, : 83–92. [Google Scholar] had been used since 1981. However, neither the epidemiology of these herpesviruses nor the efficacy of the vaccine has been thoroughly examined. In order to more clearly define the problem, an investigation was carried out to establish the patterns of EHV-1 and EHV-2 infections and to determine the effectiveness of the vaccination regime in preventing respiratory disease in foals.