Pathogenesis and countermeasures against spondylosis and staphylococcosis in broiler chickens

Spondylolisthesis and spinal abscess formation are severe diseases of broiler chickens, however, spondylosis comprises various diseases. Spondylolisthesis is characterized by spinal growth deformation. Clinical symptoms of. afflicted chickens include leg weakness, movement disorders, lameness, and paralysis. Typically, legs are pushed forward, and the weight is shifted to the ankle to initiate movement. Diseased chickens cannot ingest food or drink water and eventually die from dehydration. The etiology is a deformation of the fifth to seventh thoracic vertebrae, and particularly a slip of the sixth thoracic vertebra to the lower side, of the fifth thoracic vertebra to the anterior border, and the sixth vertebra compressing the spinal cord against the edge of the seventh vertebra. Spinal abscesses are often caused by spondylolisthesis, and other symptoms include weakness of the legs and paralysis. Gross findings often include vertebral hyperplasia of the sixth thoracic vertebra and swelling. Abscess formation occurs in the center in the sagittal section, and bone tissue is destroyed in cases of severe spreading to the fifth or seventh vertebrae which protrude into the spinal cavity from the upper vertebral body, thereby compressing the spinal cavity. Staphylococcosis in chickens differs from food poisoning in people as Staphylococcus aureus can invade the body. Staphylococcusrelated infection in chickens occurs in various forms and is known as gangrenous dermatitis, arthritis, osteomyelitis, bumble foot, generalized necrosis and septicemia, or omphalitis. Gangrenous dermatitis in broiler chickens has increased recently, particularly during summer and often occurs prior to shipment. Traditional S. aureus differs from more recent isolates, which show a negative egg yolk reaction, negative coagulase reaction, and are able to degrade mannitol. In some dead chickens, cutaneous lesions red edematous exudate can be observed on the lower abdomen and on the chest.