1. The Willows Veterinary Centre and Referral Service; Highlands Road, Shirley Solihull West Midlands B90 4NH
2. Hills Pet Nutrition UK; Building 5, Croxley Green Business Park Watford Hertfordshire WD18 8YL
3. Minnesota Urolith Center, Department of Veterinary Clinical Sciences, College of Veterinary Medicine; University of Minnesota; St Paul MN 55108 USA
4. The Royal Veterinary College; Hawkshead Lane North Mymms Hatfield AL9 7TA