Diagnosis of avian poxvirus in a red-tailed hawk (Buteo jamaicensis) in Wyoming

Abstract

Listen

Translate article

Avian pox is a contagious viral disease and is worldwide in distribution. A wide variety of domestic and wild birds are affected. Pox infections in birds are characterized by the appearance of discrete, proliferative cutaneous nodules in most cases on the unfeathered parts of the body or by lesions in the upper respiratory and oral mucosa.In 1987 a red-tailed hawk was submitted to the Wyoming State Veterinary Laboratory, Laramie, WY for diagnosis of a proliferative dermatitis of the feet and head. The bird was trapped in the wild in September, 1986 and had small skin lesions at that time. Skin scrapings were ground with a mortar and pestle, diluted with distilled water and centrifuged at 5000 rpm for 20 min. The supernatant was then centrifuged for one hr at 18,000 rpm. The pellet was resuspended in 10 drops of distilled water. One drop of the suspension was added to a mixture of the following ingredients: 20 drops of distilled water, four drops of 4% phosphotungstic acid and one drop of 0.1% BSA. The mixture was nebulized onto collodion coated 300 mesh copper grids. The material on the grids was then examined with a Philips 410 LS electron microscope for the presence of pox-like particles at 60 KV. Brick shaped pox-like virions measuring 260 X 325 nanometers were observed (Fig. 1). Histopathologic studies revealed large eosinophilic intracytoplasmic inclusion bodies typical of avian poxviral infection in the proliferative epithelium.