Caracterização epidemiológica, clínica e patológica da varíola aviária.

Abstract

Seven outbreaks of avian pox diagnosed in the Laboratory of Animal Pathology of the HV / UFCG are described, characterizing the main epidemiological, clinical-pathological aspects. A survey of bird necropsies was carried out from January 2002 to December 2015, identifying the cases of the disease. Subsequently, these cases were selected and the necropsy files were taken from the information related to the epidemiological and clinical aspects, besides the macroscopic and microscopic descriptions of the lesions. All histological slides were reviewed and, when necessary, new slides were stained and stained by hematoxylin and eosin and methenamine silver nitrate from Grocott for the diagnosis of secondary fungal infections. During this study period, seven outbreaks of smallpox in domestic birds (Gallus gallus) were diagnosed. The diseased animals had ages ranging from 15 to 40 days, were non-breed and of both sexes. All animals were raised in an extensive system. Clinically the diseased birds had mainly apathy, anorexia and crustal nodular lesions in areas of featherless skin. Macroscopically, these nodular lesions were crustous and proliferative, affecting the regions around the beak and eyeball, beyond the extremities of the paws and the wings. Histologically, there was marked hyperplasia of the epidermis stratum and ballooning degeneration of keratinocytes, associated with large numbers of intracytoplasmic eosinophilic inclusions, characteristic of avian pox. In two necropsied birds, secondary fungal infections were observed, associated with the smallpox skin lesions suggestive of Aspergillus sp and Mucor sp. Based on these data, it can be concluded that avian smallpox occurs in the form of outbreaks in the Northeast region, characterized by skin changes typical of the disease in young birds, with a high morbidity rate, and the occurrence of secondary fungal infections associated with skin lesions which can be a complicating factor for effective therapy. As a result, affected birds generally evolve to death, causing significant economic losses for small producers.