This study was carried out on outbreak of paramyxovirus infection occurred among pigeon’s flocks at Kaluobia province from 2001 to 2003. Ten flocks were affected with high morbidity and mortality rates especially among squabs. Clinically, nervous signs included circling, head and neck tremors and paralysis of extremities were detected. Loss of appetite, emaciation and greenish watery diarrhea were noticed. Grossly, congestion of most internal organs with the presence of petcchiae on the heart and proventriculus, grayish necrotic areas on the liver and pneumonic foci on the lung together with catarrhal enteritis and pale small testes were found. Serological testing by hemagglutination (H.I) test revealed presence of hemaglutinating antibodies in collected serum sample to paramyxovirus. Confirmatory diagnosis for detection of antibodies using agar gel precipitation test (AGPT) gave positive line of precipitation against reference pigeon paramyxovirus antigen. Both parasitological and bacteriological examinations revealed negative results. Microscopically, generalized congestion of blood vessels and capillaries of the most examined organs together with the presence of degeneration of the lining epithelium of the renal tubules, seminiferous tubules, hepatocytes were noticed. Mononuclear inflammatory cellular infiltration of kidneys, portal area in the liver, lamina propria of intestine and lungs were prominent. Focal hemorrhages in the heart, lungs and proventriculus with hepatic necrosis, splenic lymphoid depletion were detected. Lymphocytic meningioencephalitis characterized by congestion, perivascular lymphocytic cuffing, degeneration of purkinje cells and neurons with satellitosis, and neurophagia were recorded. According to the recorded gross and histopathological lesions which concluded that, the isolated strains of paramyxovirus in pigeons was neurotopic and viscerotropic in nature and had wide tissue tropism. Moreover, pigeons and their feces are considered as potential source of paramyxovirus infection through the contamination of poultry’s feeds causing spreading of infection between poultry flocks, so preventive PPV vaccination of pigeons and strict hygienic measurements should be taken in consideration to reduce the risk of pigeon paramyxovirus infection among poultry flocks |
