Differential diagnosis of two paralytic conditions affecting young chickens with emphasis on PCR findings

Abstract

Two paralytic conditions affecting flocks of young commercial chickens that were indistinguishable histopathologically from lesions caused by Marek's disease virus (MDV) were investigated. The first, transient paralysis, was observed only in broilers while the second condition, a spastic paralysis, was seen in replacement White Leghorn pullets aged between 6 and 16 weeks. PCR examination of DNA extracted from the blood, brain and spleens of affected birds using primers specific for MDV serotype 1 confirmed the diagnosis of MD for transient paralysis only. None of the Leghorn DNA samples was positive by PCR. Some evidence for a genetic predisposition is offered for the neuritis affecting the pullets based on epidemiological considerations.