Prevalence and risk factors associated with adventitious bursitis in live growing and finishing pigs in south-west England.

The prevalence and risk factors associated with adventitious bursitis in 912 growing and finishing pigs, originating from 20 different housing systems in south-west England, were investigated in this study. The overall prevalence of bursal lesions was 63.4%. Bursae were seen at different aspects of the hock: lateroplantar, plantar, medial and point of the hock. The most frequently affected site was lateroplantar (54.4%) followed by plantar (12.5%), medial (2.0%) and finally the point of the hock (0.7%). There was no difference in the proportions of left and right hocks affected. Bursal lesions were seen in pigs from 8 to 28 weeks of age and prevalence increased with age. Also, the longer the period pigs spent in the pen, the more likely they were to have bursitis. After accounting for the effect of herd of origin, bedding which covered the whole pen (OR 0.11) or only the lying area (OR 0.29) was the most important factor which reduced the risk of bursitis. A wet slurry film in the dunging area (OR 1.67) and a difference between the solid area and the concrete slats greater than 3 cm (OR 3.11) were significantly associated with an increased risk of bursal lesions.