Avian paramyxovirus type 1 infection in houbara bustards (Chlamydotis undulata macqueenii): Clinical and pathologic findings

Clinical and pathologic findings of avian paramyxovirus type 1 (PMV-1) in 19 houbara bustards (Chlamydotis undulata macqueenii) imported from Pakistan into the United Arab Emirates and one captive-bred bird are reported. Clinical signs included circling, walking backward, ataxia, opisthotonos, torticollis, recumbency, head tilt, head shaking, head tremor, tucking of head under keel, nasal discharge, conjunctivitis, and diarrhea. The length of time imported birds exhibited clinical signs varied from 4 days to 18 mo after importation. Hemagglutinating antibodies against PMV-1 were detected in the sera of all 17 birds from which blood samples were collected, and PMV-1 was isolated from pooled brain, spleen, and lung tissues from two birds with acute clinical signs. There were no distinctive gross lesions at necropsy, and histologic findings were consistent with but not pathognomonic for PMV-1. All houbara bustards managed in a captive breeding and restoration program established by the National Avian Research Center have been vaccinated against PMV-1 since October 1992, and no case of PMV-1 has been reported in this collection since that time.