Grogono-Thomas R, Jayawardena K G, Heller-Haupt A, Varma M G, Woodland R M
Department of Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, Boltons Park, Hertfordshire.
Vet Rec. 1999 Aug 28;145(9):254-6. doi: 10.1136/vr.145.9.254.