An epizootiological study of acute death syndrome and leg weakness in broiler chickens in western Canada.

In a survey of 51 broiler chicken flocks, the incidence of chickens dying from acute death syndrome and of those with skeletal deformities varied from 0.71 to 4.07% and from 0.46 to 4.08% among the flocks, respectively. The average incidence of those with skeletal deformities was 1.72%; 1.10% were culled in the field, and 0.62% were condemned or downgraded as carcasses. The major types of skeletal deformities were valgus deformation of the intertarsal joint (70%), varus deformation of the intertarsal joint (9%), tibial rotation (7%), and spondylolisthesis (14%). The strain and source of chickens and the management and nutritional practices were recorded for each flock. Statistical analyses were conducted in an attempt to identify factors that might correlate with the incidence of either chickens dying from acute death syndrome or those with skeletal deformities. Results of these analyses are discussed.