1. Clever Dog Lab, Messerli Research Institution, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, Vienna, Austria and Senior Family Dog Project, Department of Ethology, Eötvös Loránd University, Budapest, Hungary
2. Clever Dog Lab, Messerli Research Institution, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, Vienna, Austria and Wolf Science Center, Messerli Research Institute, Vienna, Austria
3. Senior Family Dog Project, Department of Ethology, Eötvös Loránd University, Budapest, Hungary
4. Clever Dog Lab, Messerli Research Institution, University of Veterinary Medicine Vienna, Medical University of Vienna, University of Vienna, Vienna, Austria
5. Royal Canin Research Centre, Aimargues, France