Investigation of contagious tumor diseases in Luhua chicken

To investigate the co-infection status of tumor diseases from Chinese native breed "Luhua" in Shandong province,serums were dynamically detected for antibody of ALV-J,ALV-A/B,REV,and antigen p27 of ALV from cloacal swabs samples of free range Luhua chickens separately at the age of 65,120,190 day and 240 day were also detected.The sick or dead chickens manifesting tumor lesions were necropsy,histopathology and examined by PCR.The results showed that the ALV-A/B antibody was positive for 13.24% at the age of 240 days and REV antibody was positive at the age of 120 days and increased with age,while ALV-J antibody was always negative.Positive rate of antigen p27 was from 34.21% to 66.18%.The mortality was 32% from egg laying stage to the age of 240 day.Numerous similar nodular lesions and resembling tumors in one or more tissues were seen at necropsy and some sick chickens' sciatic nerve was edematous.Histopathology findings revealed large islands of lymphocytes in tissues containing tumors.Among 16 samples,14 samples were detected positive for ALV-J(87.50%),13 samples for MDV(81.25%),2 samples for REV(12.5%) and co-infection rate was 6.30%.All the findings observed in this case were considered to be related with the MDV,REV and ALV mixed infection.