Hardy J I, Sinclair G, Fox M T, Loeffler A
Veterinary Clinical Sciences, Royal Veterinary College, University of London, Hawkshead Lane, South Mymms, Hatfield, Hertfordshire AL9 7TA, UK.
Vet Rec. 2012 Oct 6;171(14):351. doi: 10.1136/vr.101001. Epub 2012 Sep 5.