Isolation and identification of a falcon herpesvirus
Gough, R.E.; Drury, S.E.; George, A.D.; Randall, C.J.
Veterinary Record 132(9): 220-221
1993
ISSN/ISBN: 0042-4900 PMID: 8383897 Document Number: 414401
A 35-year-old male hybrid falcon imported from Germany 3 years previously and from a large collection of falcons, was submitted for PM examination after it had died suddenly after approximately 24 hours of anorexia. The carcass, which was in good condition showed signs of dehydration, the liver and spleen were swollen with miliary pale foci throughout the liver and large white nodular lesions on the surface of the spleen; the kidneys were pale due to urate retention. Histologically, there were lesions of an acute multifocal necrosis throughout the liver and extensive necrosis had resulted in destruction of much of the spleen. Confluent monolayers of chicken embryo live cultures and embryonated hens eggs were inoculated with liver and spleen samples from the falcon. Focal-type cytopathic effect was seen which progressed to complete destruction of cell monolayer after 5 days incubation. No embryonic mortality occurred followed inoculation by the allantoic cavity route but oedema and thickening of the chorio-allantoic membrane was seen 7 days after inoculation. Electron microscopy of concentrated extracts from the infected cultures and membranes revealed virus particles with typical herpesvirus morphology. Using monospecific antiserum to the falcon herpesvirus prepared SPF chickens, the homologous neutralizing antibody titres, expressed as log2 of the reciprocal of the highest dilution giving complete neutralization of 100 median tissue culture infective doses of virus, ranged from 23.5 to 26.2. In cross neutralization tests performed using other avian herpesviruses, and monospecific antisera against these other viruses no significant neutralization was recorded except for a low level one-way neutralizing value between the falcon herpesvirus and pigeon herpesvirus antiserum. The origin of the infection was not established.