Comprehensive Analyses of the Bacterial Population in Non-Healing Claw Lesions of Dairy Cattle.
Authors: Hori Kaoru, Taniguchi Takako, Elpita Trigan, Khemgaew Rathanon, Sasaki Satomi, Gotoh Yasuhiro, Yasutomi Ichiro, Misawa Naoaki
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Bacterial Populations in Non-Healing Claw Lesions of Dairy Cattle Non-healing claw lesions (NHCLs)—encompassing toe necrosis, non-healing white line disease, non-healing sole ulcers, and non-healing verrucous-like lesions—represent a distinct clinical entity in dairy cattle whose microbial aetiology remains poorly defined, despite suspected links to bovine digital dermatitis. Japanese researchers employed 16S rRNA metagenomic sequencing alongside culture-dependent methods on 12 NHCL samples from five farms, comparing bacterial populations against healthy hoof tissue controls to characterise the microbial communities involved. Whilst Treponema species and Fusobacterium necrophorum were readily detected using PCR and immunohistochemistry (mirroring findings in digital dermatitis), next-generation sequencing revealed these organisms were not numerically dominant, and the predominant bacterial genera varied significantly between lesion types and individual animals. This discrepancy between detection and abundance suggests that NHCLs possess a distinctly different pathogenic mechanism from classical digital dermatitis, and that lesion-specific or herd-specific microbial profiles may drive disease development. For practitioners, these findings underscore that standard digital dermatitis protocols may require modification for NHCL management, and that targeted farm-level investigation of local bacterial populations could help refine prevention and treatment strategies.
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Practical Takeaways
- •Non-healing claw lesions represent a distinct disease entity from bovine digital dermatitis despite suspected association; diagnostic and treatment approaches may need to differ accordingly.
- •The variable bacterial populations in NHCLs suggest that single-pathogen treatments may be ineffective; management strategies should account for farm-specific and individual-cattle microbial profiles.
- •Culture-independent methods (NGS) reveal different bacterial communities than culture-dependent methods, emphasizing the need for comprehensive microbiological characterization in claw disease research.
Key Findings
- •Treponema species and Fusobacterium necrophorum were detected by PCR and immunohistochemistry in NHCLs but were not predominant by NGS analysis, contrasting with their prevalence in BDD.
- •Bacterial populations in NHCLs varied significantly among lesion types (TN, nhWLD, nhSU, nhVLL), suggesting distinct microbial communities rather than a uniform etiology.
- •The predominant bacterial genera differed among individual cattle and/or farms, indicating multifactorial disease with variable microbial associations.