An epornitic of avian pox in houbara bustards (Chlamydotis undulata macqueenii).

An epornitic of avian pox occurred in a flock of 123 houbara bustards (Chlamydotis undulata macqueenii) received at the Sulman Falcon Hospital in the State of Bahrain in February 1993. Birds displayed conjunctivitis, excessive lacrimation and papilloma-like growths forming amorphous clusters on the third eyelid and on the conjunctiva. Examination of eyelid samples under transmission electron microscopy revealed pox virus particles displaying the classical morphology of vaccinia-avipox virions. Typical pox lesions were also detected 5 days post infection (p.i.) on chorioallantoic membrane (CAM). The virus titre on CAM was 10(7) focus-forming units (FFU)/ml. In tissue culture, only a slight cytopathogenic effect (CPE) was detected 5 days p.i. the virus titre on cell cultures was 10(4.5)FFU/ml. The virus infection in cell culture appeared to be abortive and no CPE was seen after three passages in secondary chicken embryo fibroblasts. No neutralization of the cell-grown virus was detected on serological studies using antisera directed against fowl, pigeon, canary and sparrowpox viruses. The discussion is framed around the different cultural properties of the houbara bustard pox virus isolate and its relationship to other known viral strains.