Epidemiological features and pathological study of avian leukosis in turkeys' flocks

Abstract

Aim:The purpose of this study was focused on the identification of tumor diseases in turkeys on the basis of a detailed description of epidemiological features, clinical signs, lesions, and histopathological changes.Materials and Methods:Outbreak of a tumor disease in turkeys was investigated in various regions of Eastern Algeria. Four turkeys’ flocks aged from 17 weeks were affected, resulting to mortality often over 10%, on a period of 15 days. The main epidemiological characters, clinical signs, and lesions were observed throughout all the course of the disease. Serum samples were collected from affected turkeys in each flock to detect p27 antigen in enzyme-linked immunosorbent assay (ELISA) test to diagnose avian leukosis virus (ALV). Portions of sciatic nerves and livers are taken from dead turkeys for microscopic examination.Results:The disease was characterized by clinical signs such as anorexia, weakness, and diarrhea. Necropsy of the dead birds showed hepatomegaly and gross splenomegaly with neoplastic nodules or gray foci and diffuse infiltration in the myocardium and lungs. ALV antigen test using ELISA confirmed the presence of virus leukosis. Histopathological sections of the liver had proliferations of lymphoblastoid cells and absence of any modifications or lymphocytic infiltration in peripheral nerves.Conclusion:The present study confirms that this disease condition is caused by lymphoid leukosis.

Avian Leukosis: Will We Be Able to Get Rid of It?

“…Turkey cells are susceptible to ALV exogenous subgroups, although some show resistance to ALV-B, D, and J [121,137]. In 2017, Zeghdoudi et al [138] reported an outbreak of tumor disease in turkey flocks in Eastern Algeria, with a mortality rate of 10% in animals aged 17 weeks and older. Tumors tested positive to the ALV p27 (CA) antigen by ELISA.…”

Current Epidemiology and Co-Infections of Avian Immunosuppressive and Neoplastic Diseases in Chicken Flocks in Central China

“…Avian leukosis (AL) caused by ALV is a vertically-transmitted disease that results in severe immunosuppression, multiple organ retardation, atrophy, and tumours in chickens, and leads to a serious decline in performance and a large number of deaths [1]. ALV belongs to the genus Alpharetrovirus of the subfamily Orthoretrovirinae [12] and can be divided into seven subtypes, including ALV-A, ALV-B, ALV-C, ALV-D, ALV-E, ALV-J, and ALV-K. Clinically, three subtypes of ALV-A, ALV-B, and ALV-J are more commonly occurring in broilers, layers, breeders, and turkeys [13][14][15][16]. However, to date, no effective vaccine or specific drugs are available for the control of AL, except for the eradication of ALV to block its vertical transmission and spread in chicken flocks.…”