OBJECTIVE: To retrospectively compare the efficacy and duration of effect of three commonly used locoregional blocks in dogs undergoing pelvic limb orthopaedic surgery.
METHODS: Retrospective clinical study.
METHODS: A total of 236 dogs that underwent pelvic limb surgery and were administered a locoregional technique.
METHODS: A total of 236 hospital records were reviewed and 230 included in statistical analysis. Dogs were grouped as following: electrostimulation-guided pre-iliac femoral and sciatic nerve block (group PFS, n = 70); ultrasound-guided saphenous and sciatic nerve block (group SS, n = 76); or lumbosacral epidural (group EPI, n = 84). In group EPI, bupivacaine 0.5% or ropivacaine 0.75% was used with morphine. Dogs were pain scored (short form of the Glasgow Composite Measure Pain Scale) hourly following recovery from anaesthesia. Analysed data included: time to first postoperative dose of methadone, pain score at that time, intraoperative rescue analgesia, intraoperative hypotension and ability to walk and urinate overnight. Separate analyses were performed including all pelvic limb surgeries and including only elective stifle surgeries. Kruskal-Wallis and Mann-Whitney tests were performed. A p value < 0.05 was considered significant. The median (range) is reported.
RESULTS: For all pelvic limb surgeries, the time to first postoperative methadone was 530 (110-1337), 440 (140-1030) and 466 (135-1094) minutes in groups EPI, PFS and SS, respectively, and was not significantly different. Postoperatively, 10/84, 15/70 and 12/76 dogs in groups EPI, PFS and SS, respectively, did not require methadone (nonsignificant). Significantly fewer dogs in group EPI (18%) required intraoperative rescue analgesia compared with group SS (38%), but not compared with PFS (30%). Significantly more dogs in group EPI had hypotension intraoperatively (30%) and urinary retention postoperatively (62%).
CONCLUSIONS: Intraoperative analgesia may be superior with EPI than SS for some surgeries of the pelvic limb, but not for stifle surgeries. All three techniques provided similar requirement for postoperative analgesia, but EPI caused higher incidence of intraoperative hypotension and postopertive urinary retention.

OBJECTIVE: To evaluate the efficacy, in terms of the amount of rescue analgesia required, and the clinical usefulness of epidural injection of morphine with bupivacaine or levobupivacaine for elective pelvic limb surgery in dogs during a 24-hour perioperative period.
METHODS: Prospective, blinded, randomized clinical study.
METHODS: A group of 26 dogs weighing 31.7 ± 14.2 (mean ± standard deviation) kg and aged 54 ± 36 months.
METHODS: All dogs were premedicated with methadone intravenously (0.2 mg kg-1) and anaesthesia induced with diazepam (0.2 mg kg-1) and propofol intravenously to effect. After induction of anaesthesia, dogs randomly received a lumbosacral epidural injection of morphine 0.1 mg kg-1 with either levobupivacaine 0.5% (1 mg kg-1; group LevoBM) or bupivacaine 0.5% (1 mg kg-1; group BM). Cardiovascular, respiratory and temperature values were recorded during the intra- and postoperative period. A visual analogue scale, subjective pain scale, sedation scale and the short form of the Glasgow pain scale were assessed every 6 hours after epidural injection during 24 hours. The ability to stand and walk, neurological deficits and other side effects were assessed at the same time points. The amount of rescue analgesia (sufentanil intraoperatively and methadone postoperatively) was recorded.
RESULTS: No statistically significant differences were found between groups for any of the recorded data, with the exception of the incidence of spontaneous urination and postoperative rescue analgesia requirement. In group LevoBM four dogs spontaneously urinated at recovery while none of the dogs in group BM did (p = 0.03) and seven dogs of group LevoBM required postoperative rescue analgesia versus none of the dogs in the BM group (p = 0.005).
CONCLUSIONS: and clinical relevance Epidural LevoBM is a suitable alternative to BM in healthy dogs during elective pelvic limb surgery. Epidural BM produced more urinary retention but better pain control compared to the same concentration and dose of LevoBM in dogs.