Twelve adult female sheep were used with an average body weight of 47.37 ± 11.4 kg (study III). This experiment was approved by the Ethics Committee of the Faculty of Veterinary Medicine, University of Helsinki.
Laboratory-bred beagle dogs, both male and female, aged one year and weighing 9.0 to 13.2 kilograms were used (studies I–II and IV–V). All the experimental manipulations of the dogs were approved by the Committee on Animal Experimentation of Kuopio University. The animals were kept in large outdoor/indoor runs with shelter before the operation, in separate cages for 1–2 days after the operation and thereafter again in the large runs for the duration of the study. The dog chew was Serti® (Suomen Nestle, Helsinki, Finland).