Proof of an optimized salicylic acid paste-based treatment concept of ulcerative M2-stage digital dermatitis lesions in 21 dairy cows

Maher Alsaaod*, Tim K. Jensen, Lea Miglinci, Corinne Gurtner, Sabine Brandt, Jeanette Plüss, Eveline Studer, Adrian Steiner

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

4 Citationer (Scopus)

Abstract

The efficacy of salicylic acid paste (SA) in the treatment of ulcerative bovine digital dermatitis (BDD) was assessed by combining clinical and histopathological analyses with molecular biological techniques. The latter were conducted in a blinded manner to reach maximum objectivity. Prior to treatment, M2-stage BDD lesions (n = 26, diagnosed in 21 dairy cows) exhibited ulceration, with severe perivascular, chronic, lymphoplasmacytic dermatitis and extensive keratinolysis being noted in most cases. Pretreatment biopsy samples (n = 12) followed by povidone-iodine ointment under bandage for one week before administration of SA paste were tested positive for Treponema spp. by blinded PCR and fluorescent in situ hybridization (FISH). Subsequent treatment consisted of application of SA and bandaging at weekly intervals until lesions had completely resolved. The treatment duration ranged between 2 and 4 weeks. Complete healing was achieved in 100% of cases, with 2/21 animals requiring a second round of treatment upon disease reoccurrence. Importantly, only 3/ 26 biopsies taken from previously affected sites still tested positive by Treponema PCR, and in another biopsy, the outermost layers of the stratum corneum scored weakly positive by Treponema-specific FISH. None of these Treponema DNA-positive biopsies showed signs of ulceration. One case exhibited focal keratinolysis. Positive PCR or FISH in these cases may have arisen from DNA traces of dead bacteria or environmental contamination during biopsy harvesting. To our knowledge, this is the first study on blinded molecular biological monitoring of the therapeutic efficacy of SA with respect to treponemal infection, and on complete BDD M2-stage remission in all animals achieved by SA treatment according to an optimized protocol. Although the etiology of BDD is considered as multifactorial, our data further support the concept that treponemes have a decisive role in BDD pathogenesis.

OriginalsprogEngelsk
Artikelnummere0269521
TidsskriftPLoS ONE
Vol/bind17
Udgave nummer6
ISSN1932-6203
DOI
StatusUdgivet - 2022
Udgivet eksterntJa

Bibliografisk note

Funding Information:
This work was supported by Streuli Tiergesundheit AG (Uznach, Switzerland) and by the Heard Health Management Initiator Grant, Institute of Animal Pathology and Clinic for Ruminants (Vetsuisse Faculty, University of Bern, Switzerland). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We acknowledge Prof Johann Kofler (University of Veterinary Medicine, Vienna, Austria) and Prof Cord Drögemüller (Institute of Genetics, Bern, Switzerland) for their support and the farmers for their participation.

Publisher Copyright:
© 2022 Alsaaod et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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