OBJECTIVE: Analgesic regimes were compared in pregnant ewes after laparotomy by measuring thermal (TT) and mechanical (MT) nociceptive thresholds. STUDY DESIGN: Prospective randomised experimental study. ANIMALS: Pregnant ewes at 121 days gestation underwent laparotomy as part of another research project. METHODS: Thermal and mechanical thresholds were measured before, and 2, 6, 24 and 48 hours after surgery. Thermal stimuli were delivered to the lateral aspect of the metatarsus via a skin-mounted probe, and mechanical stimuli to the contralateral site via a pneumatically driven 1.5 mm diameter pin. Each test was performed five times, alternating thermal and mechanical stimuli, with ten minutes between thermal stimuli. At the end of surgery ewes received either: 75 μg hour(-1) transdermal fentanyl patch (medial thigh) (group FP) (n = 8), or 3 μg kg(-1 ) hour(-1) intra-peritoneal medetomidine via an osmotic pump (group IPM) (n = 8) inserted immediately prior to closure. Data were analysed using the Kruskal-Wallis RS Test (p