Comparison between methadone and buprenorphine within the QUAD protocol for perioperative analgesia in cats undergoing ovariohysterectomy.

OBJECTIVES: The aim of this study was to investigate the analgesic efficacy of methadone vs buprenorphine within the QUAD protocol for anaesthesia in cats undergoing ovariohysterectomy. METHODS: One hundred and twenty cats were recruited to an assessor-blinded, randomised clinical trial. Cats received either methadone (5 mg/m2) or buprenorphine (180 µg/m2) combined with ketamine, midazolam and medetomidine intramuscularly. Anaesthesia was maintained with isoflurane in oxygen. Atipamezole was administered at extubation. Pain was assessed using the feline Composite Measure Pain Scale (CMPS-F), a dynamic interactive visual analogue scale (DIVAS) and mechanical nociceptive threshold (MNT). Sedation, pain, heart rate and respiratory rate were measured prior to QUAD administration, before intubation, and 2, 4, 6 and 8 h post-QUAD administration. If indicated by the CMPS-F, rescue analgesia was provided with 0.5 mg/kg of methadone administered intramuscularly. Meloxicam was administered after the last assessment. Differences in pain scores between groups were compared using a two-way repeated-measures ANOVA and requirement for rescue analgesia was compared using a χ2 test. RESULTS: Cats administered methadone had lower CMPS-F scores over time (P = 0.04). Eighteen of 60 cats required rescue analgesia in the methadone group vs 29/60 in the buprenorphine group (P = 0.028). All cats that received rescue analgesia required it within 6 h post-QUAD administration. There were no differences between groups in MNT or pain measured using the DIVAS. CONCLUSIONS AND RELEVANCE: Methadone produced clinically superior postoperative analgesia for the first 8 h after neutering than buprenorphine when used within the QUAD protocol.

[Painful procedures in small ruminants - castration of rams and bucks. - An overview]. / Schmerzhafte Eingriffe bei kleinen Wiederkäuern: Kastration von Böcken.

The castration of farm animals is practiced routinely throughout the world and the procedure is subject to different levels of regulation in different countries. In Germany, painful procedures in animals are regulated by the animal welfare act. However, the indications for acceptable methods of lamb and kid castration are still under discussion. There are distinct differences between the theoretical requirements of this legislation and experiences in practice. When male lambs are kept for many months with their dams, or with ewe lambs, castration is essential to avoid unwanted pregnancies and the slaughter of pregnant females. In the opinion of the authors, it is essential that castration of small ruminants must remain possible. However, the methods used for these painful procedures need to be reassessed and if necessary new regulations established. When castration is necessary, sufficient anaesthesia and analgesia must be used irrespective of species, age and method. To make this possible potent anaesthetics and analgesics urgently need to be licensed for use in these species. This would provide an evidence base for their use and extricate veterinary practitioners from the need to use the cascade system with its associated liabilities. Current literature has been reviewed here and possible new approaches discussed in order to establish solutions that are suitable for the animals, their keepers and veterinarians.

Effect of topical vapocoolant spray on perioperative pain response of unweaned calves to ear tagging and ear notching.

OBJECTIVE: To evaluate the efficacy of a vapocoolant spray to provide local anaesthesia for calves during ear tagging and ear notching. STUDY DESIGN: Randomized study. ANIMALS: Twenty Black Angus calves aged 4-16 weeks old. METHODS: Temperature validation studies using thermocouples and a temperature data logger were conducted on dead and live tissue to determine optimal spray distance and duration to achieve tissue anaesthesia (<10 °C). A behavioural trial was conducted to assess efficacy for ear tagging and ear notching. Calves (n = 20) were randomly assigned to the vapocoolant spray (VS) or the water spray (WS) group. A 3 second spray was administered from 10 cm to both sides of the ear immediately prior to ear tagging and ear notching. A numerical rating scale (NRS) was used to score behavioural response to each procedure, with responses categorized from 0 (no response) to 3 (severe). RESULTS: Temperature and tissue validation studies indicated that a vapocoolant spray reduced dead and live tissue temperature to below nociceptive threshold levels (10 °C) for 10-16 seconds. Univariate analysis indicated that ear notching was more painful than ear tagging [odds ratio (OR) = 19.2, 95% confidence interval (CI): 5.34-68.99, p < 0.001]. When adjusted for the multivariate model, there was a significant effect of treatment, with WS calves showing higher pain response scores than VS calves (OR = 4.08, 95% CI: 1.34-12.42, p = 0.011). Ear notching resulted in greater pain response scores than ear tagging (OR = 23.19, 95% CI: 6.18-87.05, p < 0.001). CONCLUSIONS: and clinical relevance Vapocoolant spray induced local anaesthesia and significantly reduced the pain response to ear tagging and ear notching in calves. Ear notching is more painful than ear tagging. Cryoanaesthesia is an effective option for reducing the perioperative pain associated with these simple husbandry procedures.