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Objective: To evaluate the onset, magnitude and duration of thermal antinociception after oral administration of two doses of tapentadol in cats., Study Design: Prospective, randomized, blinded, experimental study., Animals: Six healthy adult cats weighing 4.4 ± 0.4 kg., Methods: Skin temperature (ST) and thermal threshold (TT) were evaluated using a wireless TT device up to 12 hours after treatment. Treatments included placebo (PBO, 50 mg dextrose anhydrase orally), buprenorphine (BUP, 0.02 mg kg -1 ) administered intramuscularly, low-dose tapentadol (LowTAP, 25 mg orally; mean 5.7 mg kg - 1 ) and high-dose tapentadol (HighTAP, 50 mg orally; mean 11.4 mg kg - 1 ) in a blinded crossover design with 7 day intervals. Statistical analysis was performed using anova with appropriate post hoc test (p ≤ 0.05)., Results: Salivation was observed immediately following 11 out of 12 treatments with tapentadol. The ST was significantly increased at various time points in the opioid treatments. Hyperthermia (≥ 39.5 °C) was not observed. Baseline TT was 45.4 ± 1.4 °C for all treatments. Maximum TT values were 48.8 ± 4.8 °C at 1 hour in LowTAP, 48.5 ± 3.0 °C at 2 hours in HighTAP and 50.2 ± 5.3 °C at 1 hour in BUP. TT significantly increased after LowTAP at 1 hour, after HighTAP at 1-2 hours, and after BUP at 1-2 hours compared with baseline values. TTs were significantly increased in BUP at 1-2 hours compared with PBO., Conclusion and Clinical Relevance: Oral administration of tapentadol increased ST and TT in cats. The durations of thermal antinociception were similar between HighTAP and BUP, both of which were twice as long as that in LowTAP. Studies of different formulations may be necessary before tapentadol can be accepted into feline practice., (Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Objective: To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed., Study Design: Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time., Animals: One hundred and fifteen healthy, loose-housed Danish Holstein cattle., Methods: We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0-10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0-1000 gf). Each cow received 5-6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant., Results: The CVs did not differ [range 0.34-0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01)., Conclusion and Clinical Relevance: All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia., (© 2014 The Authors Veterinary Anaesthesia and Analgesia published by John Wiley & Sons Ltd on behalf of Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.)

An adult male crossbred dog was referred with a history of a road traffic accident that took place 1 month earlier. Neurological examination revealed paraplegia with absent nociception in the pelvic limbs. On epaxial palpation, significant curvature of the anatomical axis of the spine between the third and fourth lumbar vertebrae was observed, with the presence of a bone end almost piercing the dog's skin. Survey radiographs of the lumbar spine revealed severe dislocation between L3 and L4 vertebrae. During surgery, the spinal cord was not visible between the dislocated segments. Because of difficulties in reducing the lumbar luxation during surgery, vertebrectomy and vertebral shortening were performed. After alignment between vertebrae L3 and L5, eight cortical orthopaedic screws and bone cement were used for fixation. After 30 days, the dog started to use a wheelchair and was considered by its owner to have a good quality of life with no evidence of pain. To the authors' knowledge, this is the first case of severe luxation treated by total vertebrectomy and spine shortening in a dog. This surgery can be considered as an option in the management of severe spine luxation when the spinal cord is physically transected., (© 2014 British Small Animal Veterinary Association.)

Objective: To evaluate antinociceptive effects and pharmacokinetics of butorphanol tartrate after IM administration to American kestrels (Falco sparverius)., Animals: Fifteen 2- to 3-year-old American kestrels (6 males and 9 females)., Procedures: Butorphanol (1, 3, and 6 mg/kg) and saline (0.9% NaCl) solution were administered IM to birds in a crossover experimental design. Agitation-sedation scores and foot withdrawal response to a thermal stimulus were determined 30 to 60 minutes before (baseline) and 0.5, 1.5, 3, and 6 hours after treatment. For the pharmacokinetic analysis, butorphanol (6 mg/kg, IM) was administered in the pectoral muscles of each of 12 birds., Results: In male kestrels, butorphanol did not significantly increase thermal thresholds for foot withdrawal, compared with results for saline solution administration. However, at 1.5 hours after administration of 6 mg of butorphanol/kg, the thermal threshold was significantly decreased, compared with the baseline value. Foot withdrawal threshold for female kestrels after butorphanol administration did not differ significantly from that after saline solution administration. However, compared with the baseline value, withdrawal threshold was significantly increased for 1 mg/kg at 0.5 and 6 hours, 3 mg/kg at 6 hours, and 6 mg/kg at 3 hours. There were no significant differences in mean sedation-agitation scores, except for males at 1.5 hours after administration of 6 mg/kg., Conclusion and Clinical Relevance: Butorphanol did not cause thermal antinociception suggestive of analgesia in American kestrels. Sex-dependent responses were identified. Further studies are needed to evaluate the analgesic effects of butorphanol in raptors.

Objective: To determine whether butorphanol induces thermal antinociception in green iguanas (Iguana iguana) and assess the human observer effect on quantitative evaluation of butorphanol-induced analgesia., Animals: 6 juvenile green iguanas., Procedures: Skin temperature was recorded, and then a direct increasing heat stimulus was applied to the lateral aspect of the tail base of each iguana. Temperature of the stimulus at which the iguana responded (thermal threshold) was measured before and for 8 hours after IM injection of either butorphanol tartrate (1.0 mg/kg) or an equal volume of saline (0.9% NaCl) solution. Six experiments (butorphanol [n = 3] and saline solution [3]) were conducted with the observer in the iguanas' field of vision, and 11 experiments (butorphanol [n = 5] and saline solution [6]) were conducted with the observer hidden from their view. The interval between treatments or tests was ≥ 1 month., Results: Temperature difference between thermal threshold and skin temperature when iguanas were administered saline solution did not differ from temperature difference when iguanas were administered butorphanol regardless of whether the observer was or was not visible. Temperature difference between thermal threshold and skin temperature was significantly lower when iguanas were tested without the observer in visual range, compared with the findings obtained when iguanas were tested with an observer in view, at multiple times after either treatment., Conclusions and Clinical Relevance: Intramuscular administration of 1.0 mg of butorphanol/kg did not induce thermal antinociception in juvenile green iguanas. The visible presence of an observer appeared to influence the results of noxious stimulus testing in this reptile species.