Association between bovine digital dermatitis treponemes and a range of 'non-healing' bovine hoof disorders

摘要

Bovine digital dermatitis (BDD) is an infectious disease causing lameness in cattle, which has spread worldwide. The major aetiological infectious agents in BDD lesions are reported to be spirochaetal bacteria, and three phylo-groups have been isolated in the USA and UK (Treponema medium-hke; Treponema phagedenis-hke and Treponema denticola-like BDD spirochaetes). In the past 10 years; there have been reports of 'new' disorders affecting the bovine digit. 'Toe necrosis' (TN) is associated with herdswith a high prevalence of BDD and consists of a non-healing lesion penetrating the horn capsule to involve the coriurn, typically at the wall of the toe. A further two 'non-healing' hoof disorders initially present clinically as the classical hoof disorders white line disease (WLD) and sole ulcer (SU); but typically are more severe and are prefixed here as 'non-healing' (nh) to differentiate the conditions. These 'non-healing' disorders are now appearing more frequently than the original diseases. Thisproject set out to identify whether BDD treponemes may be involved in these various 'non-healing' hoof disorders.