Proximal femoral degeneration in growing broiler fowl

Abstract

The pathologies in proximal femora of broilers with lameness attributed to disorders of the proximal femur, including so-called 'femoral head necrosis', are described. Samples were collected from a variety of flocks, farms and production systems. Ten 'normal' broilers were also examined. Birds were identified by a characteristic lameness whereby they used a wing for support during locomotion and hip flexion (i.e. whilst sitting down). The appearance of the proximal femora at post mortem was used to place 67 proximal femora in three categories: (a) gross disintegration of the epiphysis, physis and/or metaphysis (43 samples); (b) epiphysiolysis-separation of the cartilaginous epiphysis from the underlying femoral metaphysis (growth plate) (17 samples) and (c) apparently normal (seven samples). Samples from each category were collected for mycoplasmology, virology and bacteriology. All the samples were negative for Mycoplasma, and there was no correlation between pathology and the presence or absence of viruses, but bacteria were cultured from about half the proximal femora and most of these femora showed histological evidence of bacterial infection. Although bacterial culture was negative, evidence of bacterial infections was seen in tissue sections from a further 15 proximal femora. Serial sections were required to find the foci on bacterial lesions. 'Femoral head necrosis' was not considered appropriate to describe the pathologies seen and the term proximal femoral degeneration (PFD) was adopted. Histological examination showed that PFD was most frequently due to a bacterial chondritis and osteomyelitis, with frequent involvement of surrounding tissues. Non-lame controls all had non-bacterial pathologies in the proximal femur which were also seen in many of the lame birds and may have provided a foci for the establishment of bacterial infections. The non-bacterial pathologies when severe were considered the cause of non-infectious PFD which would cause lameness in some cases. Epiphysiolysis was either a post or peri-mortem artefact, traumatic in origin, or could be attributed to underlying growth plate (physeal) pathology which in some cases was due to bacterial infection.

Equilíbrio E Problemas Locomotores Em Frangos De Corte

“…Posteriormente, com o osso desprotegido inicia-se a degeneração óssea, sendo que esta alteração pode promover maior incidência de outras patologias locomotoras, tornando-se uma porta de entrada para patógenos (vírus e bactérias). Causa grande desconforto levando à redução do bem-estar das aves (Thorp et al, 1993), afetando-as de forma uni ou bilateralmente (Kealy, 1987).…”

Leg Weakness Pathology in Broiler Chickens

“…Studies on commercial broilers in Canada showed that deformations of long bones were the primary causes of lameness, while arthritis and osteomyelitis were only associated with 10% of lameness-related losses during the last week before slaughter (Riddell and Springer, 1985). A decade earlier, a study by Thorp et al (1993) in the UK, which planned for possible cases of birds with thigh lesions, showed a high prevalence of BCO. Also, osteomyelitis was usually diagnosed in birds with lameness, studied by Thorp and Waddington (1997).…”

“…The etiological agent was determined to be Staphylococcus aureus. The condition, named at that time bacterial chondronecrosis with osteomyelitis (BCO), was consequently reported in broilers from various parts of the world: Australia, USA, Canada, and Europe (Griffits et al, 1984;Riddell and Springer 1985;Thorp et al, 1993;Thorp and Waddington, 1997;McNamee et al, 1998). Studies on commercial broilers in Canada showed that deformations of long bones were the primary causes of lameness, while arthritis and osteomyelitis were only associated with 10% of lameness-related losses during the last week before slaughter (Riddell and Springer, 1985).…”

“…Nairn and Watson (1972) reported that the prevalence of lameness caused by BCO in broiler chickens could reach 50%, with over 5% mortality in the herd. The relative prevalence of the pathogens in cases of BCO in broiler flocks was studied at the end of the last century in Great Britain and Northern Ireland (Thorp et al, 1993;McNamee et al, 1998). Thorp et al (1993) isolated bacteria from the proximal end of the femurs with lesions, indicative of BCO.…”

“…The relative prevalence of the pathogens in cases of BCO in broiler flocks was studied at the end of the last century in Great Britain and Northern Ireland (Thorp et al, 1993;McNamee et al, 1998). Thorp et al (1993) isolated bacteria from the proximal end of the femurs with lesions, indicative of BCO. From the lesions samples, coagulase-positive staphylococci (22.2%), coagulase-negative staphylococci (11.1%), and E. coli or mixed cultures (13.3%) were isolated.…”