Assessment of haematological profile and other pathological changes in farm chickens naturally infected with chicken anaemia virus in Maiduguri

Abstract

The haematology and histopathological changes in Chicken anaemia virus (CAV) infection among apparently healthy village chickens in Maiduguri, Nigeria, were investigated using conventional PCR. A total of one hundred blood and tissue samples were obtained from the study area. Blood samples were collected in EDTA tubes for haematological analysis, while tissue samples (thymus, liver, and spleen) were collected and pooled from each of the birds in duplicates into 10% neutral buffered formalin for histopathology, and the other sample was frozen at -20oC for chicken anaemia virus DNA extraction. A total of 42/100 (42%) of the pooled tissue samples were positive for CAV DNA with the expected band size of 387 bp. Haematological findings showed no significant difference between CAV-positive and CAV- negative chickens in all the parameters examined. Microscopic changes observed in the CAV- positive samples were focal aggregations of inflammatory cells, primarily in lymphoid cells and binucleate hepatocytes in the liver, lymphoid depletion in the white pulp, arising as a result of lymphocytolysis of the lymphoid follicular cells of the spleen, and lymphoid depletion in the cortical area of the thymus. These findings are the first of their kind in this region, underscoring the need to further explore CAV epidemiology in Nigeria. The study highlights the necessity for ongoing development and implementation of reliable diagnostic methods, including molecular techniques, to inform appropriate preventive measures against this economically significant avian disease.