Submitted to: Veterinary Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/7/2006
Publication Date: 8/25/2006
Citation: Taus, N.S., Oaks, J.L., Gailbreath, K.L., Traul, D., O'Toole, D., Li, H. 2006. Experimental aerosol infection of cattle (Bos taurus) with ovine herpesvirus 2 using nasal secretions from infected sheep. Veterinary Microbiology. 116(1-3):29-36. Interpretive Summary: This study demonstrated that experimental infection of cattle with OvHV-2 is attainable via the respiratory tract, and in some instances leads to the development of MCF. Additionally, this study showed that cattle are resistant to developing disease in the current experimental infection model and may not be well suited for use in pathogenesis and vaccine development studies. Other, more susceptible species, such as bison and selected cervid species, may constitute better animal models and their use should be examined in future studies.
Technical Abstract: Infection of clinically susceptible ruminants, including domesticated cattle and American bison, with ovine herpesvirus 2 (OvHV-2) can result in the fatal lymphoproliferative and vaculitis syndrome known as malignant catarrhal fever (MCF). A reliable experimental infection model is needed to study the pathogenesis of MCF and to develop effective vaccination strategies to control the disease. An experimental aerosol infection model using sheep, the natural carriers of OvHV-2, has been developed (Taus, et al., 2004). Using the protocol and OvHV-2 inoculum established in the previous study, eight calves were nebulized with four different doses of OvHV-2 in nasal secretions from sheep. Infection status of all animals was monitored using competitive inhibition ELISA, PCR and clinical parameters. Six of eight nebulized calves became infected with OvHV-2. One calf receiving the highest dose of virus developed typical clinical, gross and histological changes of MCF. This study showed that nasal secretions collected from sheep experiencing OvHV-2 shedding episodes were infectious for cattle and capable of inducing MCF. The data also indicate that cattle are relatively resistant to disease following infection. The use of more susceptible species as experimental animal models, such as bison and selected cervid species should be examined.