Naturally Occurring Co-infection of Avian Leukosis Virus (subgroups A-E) and Reticuloendotheliosis Virus in Green Peafowls (Pavo muticus)

Abstract

Most of the neoplastic diseases affecting poultry have a viral etiology, such as Marek's disease, avian leukosis/sarcoma and reticuloendotheliosis. In the present paper, histopathology and molecular methods were performed, in addition of necropsy and gross morphology evaluation, for the differential diagnosis of these diseases in two green peafowls (Pavo muticus). The affected birds showed nonspecific signs, such as depression, anorexia, and diarrhea. At necropsy, diffuse enlargement by several times the normal size of the liver and the spleen was observed. In one of the birds, the liver presented white to grayish discoloration was present, and focal and nodular growths in the other bird. Grossly, the other visceral organs and the peripheral nerves were normal. Microscopically, most of the tumor cells were large and uniform with pleomorphic nuclei. The PCR analysis for Marek's disease virus (MDV), avian leukosis virus (ALV), lymphoproliferative disease virus (LPDV), and reticuloendotheliosis virus (REV)based on their specific sequences showed the presence of ALV subgroups A-E and REV. According to these results, definitive diagnosis was co-infection of ALV and REV in naturally-infected green peafowls.

Survey of Animal Neoplastic Cases Diagnosed in Nigerian Veterinary Teaching Hospitals, 2000–2017

“…This finding is similar to the findings of Vascellari et al (2009) [15], who reported similar results in dogs and cats and partly agrees with the findings of Witter et al (1973) [25], who reported that older birds were fully susceptible to infection with Marek's disease virus and were only slightly resistant to the development of microscopic lesions. This is also similar to the findings of Sani et al (2017) [26] for chicken and Khordadmehr et al (2017) [27], in Pea fowls. Therefore, age, breed and sex are major risk factors for neoplasm development as similarly observed in the reports of Garcia et al (2019) [24].…”

Molecular detection and phylogenetic analysis of avian reticuloendotheliosis virus from formalin fixed tissue by PCR in fancy chicken

“…REV was also integrated into another DNA virus, Marek's disease as demonstrated by Davidson and Silva, (2008). Many studies have reported that coinfection of REV with Marek's disease and Avian leukosis complex in poultry (Khordadmehr et al, 2017).…”

Avian Leukosis: Will We Be Able to Get Rid of It?

“…Natural infection by ALV-A through E has been reported in other birds, including two green peafowl (Pavo muticus) with neoplasia [146] and in wild ostriches from a farm in Zimbabwe, which tested positive for antibodies and at least one case had clinical illness [147].…”