About the Authors

David Evans

Affiliation Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia

Paul McGreevy

paul.mcgreevy@sydney.edu.au

Affiliation Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia

Competing Interests

Dr. McGreevy confirms that his colleague Honorary Associate Professor David Evans was commissioned by RSPCA (Australia) to design this study and was paid an honorarium to undertake it. 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: PM DE. Performed the experiments: PM DE. Analyzed the data: DE. Contributed reagents/materials/analysis tools: DE PM. Wrote the paper: PM DE.