About the Authors

Evan S. Sergeant

evan@ausvet.com.au

Affiliation AusVet Animal Health Services, Canberra, Australian Capital Territory, Australia

John D. Grewar

Contributed equally to this work with: John D. Grewar, Camilla T. Weyer, Alan J. Guthrie

Affiliation Veterinary Services, Western Cape Department of Agriculture, Elsenburg, South Africa

Camilla T. Weyer

Contributed equally to this work with: John D. Grewar, Camilla T. Weyer, Alan J. Guthrie

Affiliation Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa

Alan J. Guthrie

Contributed equally to this work with: John D. Grewar, Camilla T. Weyer, Alan J. Guthrie

Affiliation Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa

Competing Interests

The authors have the following interests: The participation of ES in this research was funded by private donors through the Equine Health Fund of South Africa, a division of Wits Health Consortium (Pty) Ltd (http://www.equinehealthfund.co.za/Home.aspx). The Equine Research Centre is supported by South African horse industry funding, through the Equine Health Fund. ES is employed by AusVet Animal Health Services. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: ES JG CW AG. Performed the experiments: ES. Analyzed the data: ES. Wrote the paper: ES JG CW AG.