Abstract
During an outbreak of equine herpes virus 1 (EHV-1) in a zoological institution, one Thomson´s gazelle (Eudorcas thomsoni) died acutely with neurologic signs, whereas a second individual showed neurologic signs progressing to stupor which allowed supportive therapy along with intramuscular florfenicol (Nuflor, Essex Tierarznei, München, Germany), flunixin-meglumine (Finadyne RP, Essex Tierarznei, München, Germany), and oral famciclovir (Famvir, Novartis, Barbera del Valles, Spain). During the following three days, three to six animals of a colony of guinea pigs which were housed in an adjacent room to the hoofstock area, were found dead each day. The second Thomson’s gazelle and remaining guinea pigs were euthanatized due to high risk of infection and poor prognosis. Meningoencephalitis due to EHV-1 was diagnosed in all affected animals.
This is the first report of EHV-1 in caviidae but equine herpes viruses have been described to cause fatal infections in a range of non-equid species.1,2,4,6,7 Thomson´s gazelles appear to be a particularly susceptible unnatural host.3,5,8 Equid species were assumed the reservoir and the proximity of the susceptible species to equids is considered critical. The described Thomson’s gazelles were housed in a multispecies exhibit with other hoofstock, including zebras (Equus quagga boehmi).
After the outbreak, a serologic survey of all species kept in proximity with equid species was conducted. Unfortunately, there was disagreement in the results from different laboratories on the same samples but there was clear evidence for seropositivity in the equids. Vaccination protocols were introduced to prevent further outbreaks.
Acknowledgments
The authors would like to thank Dr. Prof. B. Grummer and Dr. Prof. L. Haas from the Institute of Virology at the University of Veterinary Medicine in Hannover, Germany, for characterizing the equine herpes virus.
Literature Cited
1. Chowdhury SI, Ludwig H, Buhk H. Molecular biological characterization of equine herpesvirus type 1 (EHV-1) isolates from ruminant hosts. Virus Res. 1988;11:127–139.
2. Donovan TA, Schrenzel MD, Tucker T, Pessier AP, Bicknese B, Busch MDM, et al. Meningoencephalitis in a polar bear caused by equine herpesvirus 9 (EHV-9). Vet Pathol. 2009;46:1138–1143.
3. Fukushi H, Tomita T, Taniguchi A, Ochiai Y, Kirisawa R, Matsumura T, et al. Gazelle herpesvirus 1: a new neurotropic herpesvirus immunologically related to equine herpesvirus 1. Virology. 1997;226:34–44.
4. Hoenerhoff MJ, Janovitz EB, Richman LK, Murphy DA, Butler TC, Kiupel M. Fatal herpesvirus encephalitis in a reticulated giraffe (Giraffa camelopardalis reticulata). Vet Pathol. 2006;43:769–772.
5. Kennedy MA, Ramsay E, Diderrich V, Richman L, Allen GP, Potgieter LND. Encephalitis associated with a variant of equine herpesvirus 1 in a Thomson’s gazelle (Gazella thomsoni). J Zoo Wildl Med. 1996;27:533–538.
6. Kodoma A, Yanai T, Yomemaru K, Sakai H, Masegi T, Yamada S, et al. Acute neuropathogenicity with experimental infection of equine herpesvirus 9 in common marmosets (Callithrix jacchus). J Med Primatol. 2007;36:335–342.
7. Schrenzel MD, Tucker TA, Donovan TA, Busch MDM, Wise AG, Maes RK, Kiupel M. New hosts for equine herpesvirus 9. Emerg Infect Dis. 2008;14:1616–1619.
8. Yanai T, Sakai T, Fukushi H, Hirai K, Narita M, Sakai H, Masegi T. Neuropathological study of gazelle herpesvirus 1 (equine herpesvirus 9) infection in Thomson’s gazelles (Gazella thomsoni). J Comp Path. 1998;119:159–168.