Location: Avian Disease and Oncology Laboratory
Title: Succesive outbreaks of Marek's Disease in brown commercial layer chickens on the same farm Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 26, 2014
Publication Date: July 26, 2014
Citation: Shivaprasad, H.L., Bland, M., Fadly, A.M., Dunn, J.R., Buscaglia, C. 2014. Succesive outbreaks of Marek's Disease in brown commercial layer chickens on the same farm. Meeting Abstract. Abstract No. 16663. Technical Abstract: Marek’s disease was diagnosed based on clinical signs, gross and histopathology in 15 to 17 week-old in February of 2012 and in 10 to 13-week-old Brown laying-type chickens in December of 2012 on the same farm. The outbreak involved all the 16 houses on the farm with each house containing 20,000 chickens. The chickens had been vaccinated for Marek’s disease with HVT and SB1 vaccines in ovo. Clinical signs in chickens ranged from ataxia to paralysis and increased mortality. Gross pathology included enlarged sciatic nerves and pale diffusely enlarged or pale nodules in the liver, spleen, kidneys, proventriculus, lungs, ovaries, etc. Microscopically lymphoma was confirmed in many organs as well as infiltration of lymphocytes in the nerves and intranuclear inclusions in feather follicle epithelium. Other concurrent diseases such as coccidiosis, cryptosporidiosis, colibacillosis and necrotic enteritis were observed in many birds. The cause of the outbreak as well as virus isolation and its characterization and immunohistochemistry will be presented and discussed.