The authors and web-designer are grateful to all who have provided   advice, guidance, inspiration, encouragement, images or other assistance, in particular:

RVC e-media team: Nick Short and Sonya Powney

RVC- LIVE team: Peter Nunn

RVC Parasitology team: Anna Riddle

FAO: Drs Armando Nari and Carlos Eddi

Janssen Animal Health: Dudley Gradwell and colleagues

Merial Animal Health: Andy Forbes and Steffen Rehbein

Spanish translation: Dr Felipe Torres-Acosta and colleagues

Division of Biology, Kansas State University, USA: Professor SJ Upton

Others: Professor Mike Taylor and Eddy Krecek

Introduction