A Systematic Review of Serological and Clinicopathological Features and Associated Risk Factors of Avian Pox

Abstract

Avian pox is a viral disease of a wide range of both domestic and wild bird species caused by the virus of genus Avipox virus under the family Poxviridae. There are three main strains of the virus. These are Fowlpox, Pigeonpox and Canarypox .The disease has two forms. The dry or cutaneous form is mainly characterized by skin lesions on the unfeathered parts of the bird's body. This form of the disease has high prevalence but less severity. The other form is diphtheritic or wet form which is characterized by lesions in the mouth and upper respiratory tract. The disease is widely distributed worldwide. The disease affects birds irrespective of differences in sex, age and breed. The virus enters into the body of birds through abraded skin or bite of mosquitoes. Contaminated environment, carrier birds and mosquitoes are sources of infection. The virus can survive for long period of time in the environment. There are some factors for increase in the incidence of the disease like breed differences, Managemental practices and environmental conditions. Weakness, emaciation, difficulty in swallowing and breathing, vision problems, a reduction in egg production, soiled facial feathers, conjunctivitis and edema of the eyelids and the presence of the characteristic wart-like growths are the general clinical signs of the disease. Secondary complications are common as a result of break in the continuity of the skin caused by pox lesions. Clinical signs, gross lesions, serological tests, electron microscopy and molecular methods to identify viral genome are used for presumptive diagnosis of the disease. The presence of intracytoplasmic inclusion body known as Bollinger bodies during Histopathological examination is characteristic of the disease. With few exceptions the disease only causes drop in productive performance of birds. Mortality from primary infection of pox virus is uncommon. The presence of vaccine enables to prevent and control the disease easily as there is no effective treatment for the disease.