c Since 2008, a large increase in the numbers of cases of lameness have been seen in wild North American elk (Cervus elaphus) from Washington State, USA. The most recent cases manifested as foot lesions similar both clinically and pathologically to those seen in digital dermatitis (DD) in cattle and sheep, a disease with a bacterial etiopathogenesis. To determine whether the same bacteria considered responsible for DD are associated with elk lameness, lesion samples were subjected to bacterial isolation studies and PCR assays for three phylogroups of relevant DD treponemes. The DD treponemes were isolated from lesional tissues but not from control feet or other areas of the diseased foot (including the coronary band or interdigital space), suggesting that the bacteria are strongly associated with DD lesions and may therefore be causal. In addition, PCR analysis revealed that all three unique DD treponeme phylotypes were found in elk hoof disease, and in 23% of samples, all 3 DD-associated treponemes were present in lesions. Sequence analysis of the 16S rRNA gene showed that the elk lesion treponemes were phylogenetically almost identical to those isolated from cattle and sheep DD lesions. The isolates were particularly similar to two of the three culturable DD treponeme phylotypes: specifically, the Treponema medium/Treponema vincentii-like and Treponema phagedenislike DD spirochetes. The third treponeme culturable phylogroup (Treponema pedis), although detected by PCR, was not isolated. This is the first report describing isolation of DD treponemes from a wildlife host, suggesting that the disease may be evolving to include a wider spectrum of cloven-hoofed animals.

Digital dermatitis (DD) is an infectious lameness commonly found in dairy cattle worldwide, and it is known as bovine digital dermatitis (BDD) or papillomatous digital dermatitis (PDD). The disease was first reported in 1980 in the United States (1) and in the late 1980s in the United Kingdom (2). BDD has also been confirmed in beef cattle (3, 4), and over the last 30 years, the disease has been recognized as an important cause of bovine lameness (5).Lameness in cattle and sheep has serious animal welfare and economic implications (6-9). The effects of lameness in cattle include a decrease in milk yield (9, 10) and fertility (8, 11-13) and an increase in rate of culling (12,14). This has been found to be particularly true for cattle suffering from BDD (8, 15, 16) with a recent study of the cost of lameness in the United States estimating that on average, BDD costs $133 per case (17).BDD is now a worldwide problem, and controlling BDD on dairy operations has proven difficult. Moreover, in the last 20 years, sheep in the United Kingdom have been identified with a form of DD termed contagious ovine digital dermatitis (CODD), which is rapidly emerging as a severe infectious foot disease since it was first reported in the United Kingdom in 1997 (18-20). Now, CODD has spread into the Republic of Ireland (20), and it was recently reported in dairy goats in the United Kingdom (21), indicating further cross-species transmission. The contagious nature of DD is also evident by the reports of a manifestation of the disease in a wildlife host, North American elk (Cervus elaphus) from Washington State (22). The reports of DD in previously unaffected species, including U.S. wildlife, suggests a much greater global threat of the disease than previously considered.BDD in cattle manifests in several forms, but most frequently as an ulcerative lesion of the digital skin located immediately above the coronary band between the heel bulbs which results in severe lameness (23). The clinical features of CODD in sheep are slightly different, mainly because the initial lesion site on the sheep foot is different. CODD lesions commence at the coronary band and then run under the hoof horn capsule dorsally and abaxially (24). CODD frequently presents a particularly severe outcome where the whole horn capsule can be lost (18,(25)(26)(27). As a result of the severity of the lesions, sheep can be extremely lame, impacting the welfare of the affected sheep (28). This is concurrent with the lesion pathology identified in elk, described as erosive lesions on

No abstract

No abstract

Digital dermatitis (DD) is an infectious foot disease causing severe lameness in dairy cattle (worldwide) and sheep (UK). This study investigated whether DD Treponema phylogroups can be present on equipment used to trim ruminant hooves and, therefore, consider this trimming equipment as a possible vector for the transmission of DD. Equipment was tested after being used to trim DD symptomatic and asymptomatic cattle and sheep hooves, and subsequently after disinfection of equipment. After trimming, 'Treponema medium/Treponema vincentii-like', 'Treponema phagedenis-like' and 'Treponema denticola/T putidum-like' DD spirochaetes, were shown to be present on 23/37 (62%), 21/37 (57%) and 20/37 (54%) of knives, respectively. After disinfection, detection rates for the DD treponemes were 9/37 (24%), 6/37 (16%) and 3/37 (8%), respectively. Following culture of a swab, an isolate belonging to the T phagedenis-like spirochaetes was identified from a knife sample after trimming a DD positive cow. No isolates were obtained from knife samples after disinfection. This new data has, for the first time, identified treponemes in the farm environment, and highlighted disinfection of hoof trimming equipment between animals and between farms, as a logical precaution to limit the spread of DD.