1. From the Department of Companion Animal Clinical Studies, (Steenkamp, Buss) and the Department of Paraclinical Sciences, (Venter), Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa; the National Zoological Gardens, (Venter) P.O. Box 754, Pretoria, 0001, South Africa; the Division of Surgery (Crossley), Animal Medical Centre, 511 Wilbraham Road, Chorlton, Manchester M24 5AJ, UK. Dr. Buss' current address is Manager Veterinary Unit, Private Bag X402,...