Adventitious bursitis of the hock in finishing pigs: prevalence, distribution and association with floor type and foot lesions.

The prevalence, severity and distribution of adventitious bursitis were estimated in 3989 finishing pigs from 21 units in south-west England. The overall prevalence of adventitious bursitis was 51.0 per cent and ranged from 10.1 to 84.0 per cent in the different units. Bursae were found on four different aspects of the hock: lateroplantar, plantar, medial and point of the hock (capped hock). The median severity of the bursae at all the different sites was mild (score 1). There was a large variation in the prevalence of different bursal lesions. Lateroplantar bursae (41.8 per cent) were the most prevalent followed by plantar (12.0 per cent), medial (4.8 per cent) and capped hock (3.7 per cent). There was a significant trend in the prevalence of bursitis with floor type; pigs kept on solid concrete floors with deep straw (> 10 cm) had the lowest risk of having bursitis, and the prevalence increased successively when the floors were solid concrete with sparse straw (< 10 cm), semi-slatted and fully slatted. There was a significant association between the presence of bursitis and foot lesions.