Histopathological Investigation of Fowl Adenovirus (FAdV) Infections in Broiler Chickens: A Study in Diyala Governorate

Abstract

Inclusion Body Hepatitis (IBH), is the main serotype caused by Fowl Adenovirus (FAdV), that
affecting chickens leading to substantial economic losses in poultry industry worldwide. The
virus mostly affects broiler chickens aged 3-6 weeks, resulting in mortality rates ranging from
10-30%. IBH is characterized by friable, enlarged livers with hepatic necrosis and ecchymotic
hemorrhages, often accompanied by lesions in the kidney and spleen. This study was performed
at the College of Veterinary Medicine, University of Diyala, aim to identifying the strains of this
virus and detect the disease to confirm its presence in Diyala Governorate. This was achieved by
conducting histopathological examinations on samples collected from post-mortem cases.
Twenty-five tissue samples were collected from several organs, including the liver, spleen, and
kidney, from five location farms in Baqubah, Al-Khalis, Al-Muqdadiyah, Al-Wajhiyah, and
Kanaan. These sections were stained using routine hematoxylin and eosin (H&E) staining
protocols. Histopathological examination of tissues infected broiler chickens with IBH- exposed
significant pathological changes. Liver sections displayed coagulative necrosis, basophilic
intranuclear inclusion bodies within hepatocytes, fatty infiltration, and subacute periportal
hepatitis. In the spleen, vascular congestion, hemorrhage, and lymphocyte depletion were
detected. Kidney segments exhibited sign of nephritis, tubular degeneration, and mild peritubular
mononuclear infiltration. Additionally, the glomeruli displayed mesangial hyperplasia,
proliferative glomerulonephritis, and thickening of Bowman’s capsule, while intranuclear
inclusion bodies were rarely detected in renal tissues. These findings highlight the extensive
tissue damage caused by IBH in affected organs. The results of the current study highlight the
pathological effects of FAdV in broiler chickens emphasize the importance of timely detection
and characterization of the virus to alleviate its economic effect on poultry rearing in Diyala
Governorate