Failure to demonstrate histological changes of digital or interdigital dermatitis in biopsies of slurry heel

Digital Dermatitis in Cattle: Current Bacterial and Immunological Findings

Globally; digital dermatitis is a leading form of lameness observed in production dairy cattle. While the precise etiology remains to be determined; the disease is clearly associated with infection by numerous species of treponemes; in addition to other anaerobic bacteria. The goal of this review article is to provide an overview of the current literature; focusing on discussion of the polybacterial nature of the digital dermatitis disease complex and host immune response. Several phylotypes of treponemes have been identified; some of which correlate with location in the lesion and some with stages of lesion development. Local innate immune responses may contribute to the proliferative, inflammatory conditions that perpetuate digital dermatitis lesions. While serum antibody is produced to bacterial antigens in the lesions, little is known about cellular-based immunity. Studies are still required to delineate the pathogenic traits of treponemes associated with digital dermatitis; and other host factors that mediate pathology and protection of digital dermatitis lesions.

The etiology of digital dermatitis in ruminants: recent perspectives

Digital dermatitis (DD) is a multifactorial polymicrobial infectious disease originally described in dairy cattle, but is increasingly recognized in beef cattle, sheep, and more recently, elk and goats. Clinical bovine lesions typically appear on the plantar surface of the hind foot from the interdigital space and heel bulb to the accessory digits, with a predilection for skin–horn junctions. Lesions present as a painful ulcerative acute or chronic inflammatory process with differing degrees of severity. This variability reflects disease progression and results in a number of different clinical descriptions with overlapping pathologies that ultimately have a related bacterial etiology. The goal of this review article is to provide a concise overview of our current understanding on digital dermatitis disease to facilitate clinical recognition, our current understanding on the causative agents, and recent advances in our understanding of disease transmission.

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

This study describes the association between bovine digital dermatitis (BDD) treponemes and three 'non-healing' bovine hoof horn lesions, namely, 'toe necrosis' (TN), 'non-healing white line disease' (nhWLD) and 'non-healing sole ulcer' (nhSU), which are disorders that involve penetration through the horn capsule to involve the corium. In this study, these non-healing disorders (n=44) were identified as foot lesions that exhibited a topical granular appearance, exuded a typical pungent smell, were severely painful to the animal involved, and typically originated from farms where BDD is endemic. Given the similarities between these 'non-healing' lesions and BDD, the authors subjected samples of diseased tissue to PCR assays to detect the presence of DNA of BDD treponemes. All the three characterised BDD treponeme groups were identified as present together in 84.2, 81.3 and 55.6 per cent of samples of TN (n=19), nhWLD (n=16) and nhSU (n=9), respectively. In contrast, healthy control horn samples from similar sites (n=16) were PCR-negative for the BDD treponemes. Hence, these non-healing hoof lesions were strongly associated with BDD treponemes. Samples from typical heel horn erosions (n=9) were also subjected to BDD treponeme PCR assays and no association could be identified between the BDD treponemes and this horn manifestation.

Survey for papillomatous digital dermatitis in Australian dairy cattle

OBJECTIVE

To determine whether Treponema-associated papillomatous digital dermatitis (PDD) occurs in Australian dairy cattle.

DESIGN

Mail-out questionnaire and histological and bacteriological examination of biopsy tissue from suspect PDD lesions.

PROCEDURE

The questionnaire was mailed to 375 veterinarians to evaluate their knowledge of PDD, determine if they had observed the disease in Australian dairy cattle, and to request biopsy material from suspicious cases. Biopsies were examined for histological and bacteriological evidence of PDD, including for the presence of spirochaetes.

RESULTS

Eighty-eight replies to the questionnaire were received (23.5%). Of 52 respondents who were aware of PDD as a possible cause of lameness, 26 reported observing the condition in Australian cattle. Of 32 respondents who were unaware of the condition, 6 reported observing lesions that might have been PDD. The majority of reports of PDD-like lesions came from the southern Australian states, the condition occurring during periods of high rainfall and proving responsive to topical or parenteral application of antimicrobials. Biopsies from five erosive lesions showed histological similarity to PDD whereas biopsies from five proliferative lesions were consistent with chronic inflammation, fibroma or cutaneous papilloma. The presence of spirochaetes was not demonstrated in any of the lesions by histological or bacteriological methods.

CONCLUSION

Anecdotal reports and analysis of biopsy material confirm that a condition similar to PDD does occur sporadically in dairy cattle in southern Australia. However, this condition has so far not been shown to be associated with the presence of spirochaetes in the lesions.

Microbiota anaeróbia isolada de bovinos com pododermatite

O presente trabalho teve como objetivo isolar e identificar espécies bacterianas anaeróbias presentes nos pés de bovinos portadores de vários graus de pododermatite. Foram utilizados 60 bovinos, distribuídos em quatro grupos de 15. O grupo I foi constituído por animais saudáveis e serviu de controle; o grupo II, por bovinos na fase inicial do processo; o grupo III, por animais portadores de pododermatite interdigital vegetativa e o grupo IV, por bovinos portadores de pododermatite necrosante. Foram colhidos fragmentos de tecido interdigital para cultura e as principais espécies bacterianas isoladas foram: Dichelobacter nodosus nos grupos II, III e IV e Fusobacterium necrophorum nos grupos III e IV, com freqüências de 26,7%, 6,7%, 20,0%, 6,7% e de 13,3%, respectivamente. Encontraram-se também Fusobacterium symbiosum em 40,0% no gb>rupo I, 6,7% no grupo II, 13,3% no grupo III e 13,3% no grupo IV, Bacteroides sp. em 6,7% nos grupos I e IV, Bacteroides ruminatus em 33,3% no grupo I, 6,7% no grupo II, 33,3% no grupo III e 13,3% no grupo IV, Bacteroides oralis em 6,7% no grupo III e Fusobacterium mortiferum em 6,7% no grupo IV.