Pathomorphological Investigations on the Incidence of Axial Skeleton Pathology Associated with Posterior Paralysis in Commercial Broiler Chickens

Abstract

The aim of the current pathomorphological study was to find out the prevalence of various pathological conditions of the axial skeleton associated with posterior paralysis in commercial broiler chickens at a farm over a prolonged period. Cases of clinical posterior paralysis at a commercial broiler chicken farm were registered over a one-year period of research. Of the examined 36 broiler flocks, signs of posterior paralysis were found in a total of 1480 (0.21%) chickens from 23 flocks. In 22 of these flocks, the chickens with posterior paralysis were recorded, marked, and put in an isolation premise where they were kept with access to food and water until the respective flocks were to be processed. In one of the flocks, posterior paralysis was found in 71 chickens at the age of 34 days in association with an outbreak of femoral head necrosis (FHN), arthritis, and osteomyelitis, which were also isolated. During the period of isolation, 13 of these chickens died, and the surviving 58 were processing at a processing plant.
　　A total of 151 vertebral columns were randomly collected from 6 isolated chicken carcasses from each of the 23 flocks at the processing plant, which had exhibited posterior paralysis, as well as following autopsy of the 13 chickens that had died from the isolation premise of the flock where simultaneous occurrence of FHN, arthritis, and osteomyelitis was observed. The samples were submitted to gross, histological, radiography, and microbiological examinations. Spondylolisthesis (64; 42.3%), followed by cases of spondylosis with ankylosis, osteosclerosis and fractures (54; 35.8%), vertebral osteomyelitis (19; 12.6%), and osteochondrosis with scoliosis and fractures (14; 9.3%) were the most prevalent conditions.