ClinicoPathological Studies on The Effect of Duck Viral Hepatitis In Ducks

DVH is an acute viral disease of young ducklings characterizedby sudden onset rapid course and high mortality (95-100 %). Twohundred and five white Pekin ducklings (one day old) were dividedinto eleven groups. Gp. (I) was the negative control. Groups (2, 3 and4) were vaccinated with DHV (0.2 ml IM) at the age of 2 days (gp. 2),10 days (gp. 3), 2 and 10 days (gp. 4). Groups (5 and 6) were infectedwith DHV (0.2 ml/bird I1M) at the ages of 16 and 24 days,respectively. Gp. (7) was vaccinated at the age of 2 days andchallenged at the age of 16 days with DHV. Gp. (8) was vaccinated atthe age of 10 days and challenged at the age of 24 days with DHV.Gp. (9) was vaccinated at the ages of 2 and 10 days and challenged atthe age of 24 days. Gp. (10) was infected at the age of 2 days withDHV. Gp. (11) was used to check the maternal immunity. Theducklings, in all groups, were observed daily, and the mortality rate ofeach group was recorded during the experimental period. Fiveducklings, from each group (gps. 1-9), were sacrificed weekly. Bloodsamples were collected for hematological and biochemical studies inaddition to serological test (SNT). Tissue specimens were collected atthe same time from the liver, kidneys, spleen, bursa of Fabricius,thymus and heart for histopathological examination.The signs included decrease food intake or anorexia, depressionand ruffled feathers on the 2nd, 3rd and 4th days post-infection (PI) orpost vaccination (PV) in all groups except group (10) where theducklings showed the general signs of illness. On the 3rd day PI, the