Special thanks to the following contributors & advisors (in random order):

José Kok MSc, Margje Voeten PhD, Gerard Meijer, Gerard Baars, Peter van der Eijk, Gerry Dorrestein PhD DVM, Dr Andries van Foreest DVM †, Dr Klaus Friedrich PhD DVM, Drs Nicole Reens DVM, Franc Viehoff DVM, Stijn Peters DVM for sharing their valuable knowledge.

Authors: Koen Cuyten BSc (Bears in Mind) and Jan Bos DVM (Ouwehand Zoo), The Netherlands

Design and illustrations: Associazione Perugia in Internet and Koen Cuyten (Bears in Mind)

Technique: Associazione Perugia in Internet, Italy