1. Davies White Veterinary Specialists, 5 Manor Farm Business Park, Higham Gobion, Hitchin, Hertfordshire SG5 3HR, UK
2. Idexx Laboratories, P.O. Box 4, Wetherby, West Yorkshire LS22 4ZR, UK
3. The Chestnut Veterinary Group, 1 Hoe Lane, Ware, Hertfordshire SG12 9LS, UK