ORIGINAL RESEARCH article
Front. Vet. Sci.
Sec. Animal Behavior and Welfare
Biopierces: Drug-Eluting Ear Tags for Infection Prevention in Animal Tagging
Provisionally accepted
- 1The University of Arizona, Tucson, United States
- 2University of Prince Edward Island Faculty of Sustainable Design Engineering, Charlottetown, Canada
- 3University of Prince Edward Island Department of Chemistry, Charlottetown, Canada
- 4University of Prince Edward Island Atlantic Veterinary College, Charlottetown, Canada
- 5University of Prince Edward Island Department of Pathology & Microbiology, Charlottetown, Canada
- 6Ecole de technologie superieure, Montreal, Canada
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Ear tagging is a routine practice in livestock management but is can be associated with bacterial colonization and infection at puncture sites. This study evaluated drug-eluting ear tags (Biopierce) incorporating chlorhexidine (CHX) in a poly(lactic-co-glycolic acid) (PLGA) matrix for their ability to reduce microbial burden and support wound healing. Biopierce eartags were fabricated by coating commercial ear tags with CHX–PLGA and compared to untreated controls. In vitro, Biopierces demonstrated a rapid burst release of CHX (~75% within 2 h) plateauing by 8 h, with eluates showing strong antimicrobial activity against Staphylococcus aureus in disk and tag diffusion assays. In vivo, five adult commercial boars each received one Biopierce and one control tag, with bacterial colonization assessed at 3, 7, 14, and 28 days using MALDI-TOF identification and semi-quantitative scoring. The Biopierce tags significantly reduced bacterial load, halving the prevalence of heavy contamination (27% vs. 12.6%, p = 0.0015) and doubling the prevalence of scant growth (9% vs. 21%, p = 0.017). Mean bacterial load scores were significantly lower with Biopierces (2.25 vs. 2.73, p < 0.05), and regression modeling confirmed a 20.1% reduction (p < 0.001). Histopathology at Day 28 showed trends toward reduced swelling (+45.2% vs. +57.6%) and increased full epithelialization (66% vs. 37%), though these did not reach statistical significance due to the small sample size. Taken together, these results demonstrate that Biopierce eartags provide localized CHX delivery that reduces bacterial colonization at tagging sites and may promote improved healing, supporting their potential as a practical infection and inflammation prevention strategy in livestock management.
Keywords: Animal tagging, Biomaterials, drug eluting constructs, Infection, piercing
Received: 31 Aug 2025; Accepted: 15 Dec 2025.
Copyright: © 2025 Cartmell, Naseri, Kerr, Hurnik, Martin and Ahmadi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Christopher Cartmell
Daniel Hurnik
Ali Ahmadi
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