Kaiser-Thom S, Hilty M, Axiak S, Gerber V. The skin microbiota in equine pastern dermatitis: a case-control study of horses in Switzerland.
Vet Dermatol 2021;
32:646-e172. [PMID:
33830562 PMCID:
PMC9290916 DOI:
10.1111/vde.12955]
[Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/28/2020] [Accepted: 11/16/2020] [Indexed: 01/04/2023]
Abstract
Background
Equine pastern dermatitis (EPD), a multifactorial syndrome, manifests as skin lesions of variable severity in the pastern area. Despite the widespread use of antibacterial therapy for treating this condition, little is known about the contributing bacteria.
Hypothesis/Objectives
To investigate the bacterial skin microbiota in EPD‐affected and unaffected (control) pasterns.
Animals
Case‐control study with 80 client‐owned horses; each with at least one EPD‐affected and one control pastern.
Methods and materials
Horses were grouped by the form of EPD (mild, exudative or proliferative), the assigned severity grade and type of pretreatment (disinfectant, topical antibacterial or no antibacterial pretreatment). Skin swabs were obtained, and the microbiota composition was compared between the groups.
Results
Bacterial alpha diversity was reduced in affected pasterns (P < 0.001) and this reduction was significantly associated with the EPD forms (P < 0.001), and not with the type of pretreatment (P > 0.14). Analyses of beta‐diversity confirmed a disordering of the skin microbiota (P = 0.004) in affected versus control pasterns, that was particularly profound in more severe lesions. The type of pretreatment was not significantly associated with this disordering. Four differentially abundant families were detected, of which Staphylococcaceae was the most distinct. The relative abundance of staphylococci was significantly increased in affected pasterns (P = 0.011), particularly in those that had received antibacterial treatment previously.
Conclusions and clinical relevance
Changes in the microbiota are associated with the EPD form or severity of lesions. The role of bacteria in the pathogenesis of EPD as well as the propriety and consequences of antibacterial treatment should therefore be further investigated.
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