1 Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, NMBU School of Veterinary Science, Department of Companion Animal Clinical Sciences, Small Animal Section, Box 8146 Dep., N-0033 Oslo, Norway. Electronic address: kristin.anfinsen@nmbu.no.
2 Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, NMBU School of Veterinary Science, Department of Companion Animal Clinical Sciences, Small Animal Section, Box 8146 Dep., N-0033 Oslo, Norway; Cancer Registry of Norway, Department of Research, Box 5313 Majorstuen, N-0304 Oslo, Norway. Electronic address: tom.grotmol@kreftregisteret.no.
3 Norwegian Radium Hospital, Department of Oncology, Oslo University Hospital, Box 4950 Nydalen, N-0424 Oslo, Norway. Electronic address: oyvind.bruland@medisin.uio.no.
4 Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, NMBU School of Veterinary Science, Department of Companion Animal Clinical Sciences, Small Animal Section, Box 8146 Dep., N-0033 Oslo, Norway. Electronic address: cathrine.trangerud@nmbu.no.
5 Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, NMBU School of Veterinary Science, Department of Companion Animal Clinical Sciences, Small Animal Section, Box 8146 Dep., N-0033 Oslo, Norway. Electronic address: thora.jonasdottir@nmbu.no.