title: Severe histiolymphocytic and heterophilic bronchopneumonia as a reaction to in ovo fowlpox vaccination in broiler chicks.
abstract: Broiler chickens on several farms from a single poultry company experienced neurological signs and mortality in chicks between 3 days and 10 days of age over a 3-week period after use of a fowlpox-vectored infectious laryngotracheitis virus vaccine in ovo. At necropsy the lungs contained numerous tan or gray, opaque to translucent, 0.5- to 2.0-mm nodules in the parenchyma. Microscopic lesions were a multifocal severe lymphohistiocytic and heterophilic bronchopneumonia. Immunohistochemistry was positive for fowlpox virus in macrophages and lymphocytes, and polymerase chain reaction on paraffin-embedded lung tissues was positive for a fowlpox vector virus commonly used as a vaccine. The cause of the neurological signs was not determined.
authors.affiliation: Poultry Diagnostic and Research Center, Department of Population Health, University of Georgia, Athens, GA 30602, USA. smwillia@uga.edu
authors.forename: S M
authors.initials: SM
authors.lastname: Williams
authors.forename: J A
authors.initials: JA
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Garcia
authors.forename: D
authors.initials: D
authors.lastname: Brinson
authors.forename: M
authors.initials: M
authors.lastname: Kiupel
authors.forename: C
authors.initials: C
authors.lastname: Hofacre
mesh_terms: D000818:Animals; D001996:Bronchopneumonia / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D002645:Chickens / Q000821:virology*; D005586:Fowlpox / Q000517:prevention & control*; D005587:Fowlpox virus; D008168:Lung / Q000473:pathology / Q000821:virology; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D010063:Ovum; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011201:Poultry Diseases / Q000209:etiology / Q000473:pathology*; D014765:Viral Vaccines / Q000009:adverse effects*
chemical_list: D014765:Viral Vaccines