Cardiovascular and subjective evaluations of oxymorphone/diazepam and hydromorphone/diazepam induction in experimentally induced hypovolemic dogs

Carprofen is an oral nonsteroidal anti-inflammatory drug commonly used for treatment of chronic osteoarthritic pain. The injectable formulation has some efficacy for treatment of acute surgical orthopedic pain. The purpose of this project was to assess the efficacy of oral preoperative carprofen for control of postoperative pain in dogs undergoing knee surgery for repair of ruptured cranial cruciate ligaments.
This was a randomized, placebo controlled, parallel study that investigated the effectiveness of carprofen compared to placebo. Nineteen dogs, presented to the CSU VTH, were entered into the study and randomly assigned to the carprofen (C) ( n  = 10) or placebo (P) ( n  = 9) group. Dogs received either a loading dose of carprofen (2.2 mg kg⁻¹ PO BID) or placebo starting 24 hours prior to surgery including the morning of surgery. The placebo contained lactose and liver flavoring. Pain was assessed using a pain scoring system, visual analog scale, and a loaded pressure threshold device preoperatively, and at 1, 2, 4, 6, 24, and 48 hours and 10 and 21 days postoperatively. The treatment continued for 21 days. Blood for cortisol analysis was drawn at all assessment times. Data were analyzed using a likelihood-based mixed effect model repeated measures. Data were considered significant if p  < 0.05.
Eight of 10 C dogs and 5/9 P dogs were given at least 1 dose of morphine. The mean relative dose of morphine was greater in the C group at 1 hour ( p  = 0.01) and 24 hours ( p  = 0.02). The heart rate and respiratory rate decreased postoperatively in a similar manner for both groups. There were no significant postoperative differences in cortisol levels or any measured variable. It appears that the scoring system used was not sensitive enough to detect differences in pain between a known analgesic and a placebo.     

Comparison of ketoprofen and carprofen administered prior to orthopedic surgery for control of postoperative pain in dogs.

OBJECTIVE: To compare analgesic and adverse effects of ketoprofen and carprofen when used to control pain associated with elective orthopedic surgeries in dogs. DESIGN: Prospective randomized clinical trial. ANIMALS: 93 client-owned dogs: 46 undergoing reconstruction of the cranial cruciate ligament, 47 undergoing femoral head and neck excision, and 15 control dogs anesthetized for radiographic procedures. PROCEDURE: Dogs undergoing surgery were randomly given ketoprofen, carprofen, or saline (0.9% NaCl) solution, SC, prior to surgery. Pain score and serum cortisol concentration were recorded for 12 hours after surgery for all dogs. When pain score was > or = 7, oxymorphone was administered i.m. Bleeding time was measured prior to and during surgery. RESULTS: The proportion of dogs that required oxymorphone was significantly higher for the carprofen and placebo groups than for the ketoprofen group. Pain score for the placebo group was significantly higher than for the ketoprofen and carprofen groups, 2, 8, and 9 hours after surgery. Cortisol concentration was significantly higher for the placebo group than for the carprofen group at 4 and 6 hours after surgery. Significant differences were not detected between ketoprofen and carprofen groups with respect to pain score and cortisol concentration. Bleeding time was significantly longer for the ketoprofen group than for the other groups during surgery. One dog treated with ketoprofen developed a hematoma at the surgical site. CONCLUSIONS AND CLINICAL RELEVANCE: Ketoprofen and carprofen given prior to surgery were effective for postoperative pain relief in dogs. However, ketoprofen should not be used when noncompressible bleeding may be a problem.     

Efficacy and Kinetics of Carprofen, Administered Preoperatively or Postoperatively, for the Prevention of Pain in Dogs Undergoing Ovariohysterectomy

Objective —To determine what effect the timing of carprofen administration has on the severity of postoperative pain in dogs undergoing ovariohysterectomy and to investigate the pharmacokinetics of carprofen under these conditions. Study Design —A prospective, randomized, double-blind, clinical trial. Animals —Sixty-two adult bitches weighing between 10 and 25 kgs, undergoing elective ovariohysterectomy. Methods —Examinations were performed for 20 hours postoperatively using subjective visual assessment scoring systems (DIVAS) and objective mechanical nociceptive threshold measurements. Forty dogs were assigned to one of three groups: (1) preoperative carprofen; (2) postoperative carprofen; and (3) no analgesics (saline injections). The dose of carprofen was 4.0 mg/kg subcutaneously. In another 22 bitches, the pharmacokinetics of carprofen given preoperatively or postoperatively at the same dose were examined. Results —The dogs given carprofen preoperatively had lower pain scores than the other groups, significantly so at 2 hours postextubation (P < .01 and P < .05, Kruskal-Wallis and post hoc Dunn's). Mechanical pain thresholds measured at the distal tibia showed the development of hyperalgesia at 12 and 20 hours postextubation; this was prevented by both the preoperative (P < .05 at 12 and 20 hours, Kruskal-Wallis) and postoperative (P <.05 at 20 hours, Kruskal-Wallis) administration of carprofen. Mechanical pain threshold testing at the wound showed a significant analgesic effect of carprofen. Plasma concentrations of carprofen were not directly related to analgesia; maximum plasma concentration, the area under the curve to the last data point, and area under the first moment curve up to the last data point were all significantly higher in the dogs given carprofen postoperatively (P < .05, Mann-Whitney). Conclusion—Preoperative administration of carprofen has a greater analgesic effect than postoperative administration in the early postoperative period in dogs undergoing ovariohysterectomy. Plasma levels of carprofen are not related to the degree of analgesia achieved. Clinical Relevance—Carprofen provides effective analgesia after canine ovariohysterectomy. The timing of analgesic administration is important to optimize the control of postoperative pain.     

Assessing the efficacy of perioperative oral carprofen after cranial cruciate surgery using noninvasive, objective pressure platform gait analysis

OBJECTIVE: To document, using pressure platform gait analysis, the effect of perioperative oral carprofen on limb function and pain after cranial cruciate ligament surgery in dogs. STUDY DESIGN: Blinded, prospective clinical investigation. ANIMALS: Twenty dogs with naturally occurring unilateral cranial cruciate disease. PROCEDURE: Physiologic indices, subjective pain scoring, and pressure platform gait analyses were performed before and 24, 48, and 72 hours after surgery. Correlations were assessed between methods of evaluation and the data was compared across treatment groups. RESULTS: No strong correlations were noted between physiologic data, subjective scoring systems, or gait analysis data at a walk or stance. Although average measures of limb function were nearly twice as large in dogs treated with carprofen, no significant differences between groups over time were identified. No significant differences were noted in any other measure of pain or limb function. Power analysis of peak vertical force at a walk indicated that significant difference would have been detected had the number of dogs in each group been increased to 35. CONCLUSION: When limb function was assessed with pressure platform gait analysis no statistical difference was noted between groups with respect to PVF and VI at a walk or stance, although average ground reaction forces for dogs in the carprofen group were greater than the traditional pain management group at all time points. CLINICAL RELEVANCE: Oral carprofen appears to provide some benefit for the treatment of postoperative orthopedic pain.     

Assessing the efficacy of perioperative carprofen administration in dogs undergoing surgical repair of a ruptured cranial cruciate ligament

Twenty-one otherwise healthy dogs that presented for surgical repair of a ruptured cranial cruciate ligament were blindly and randomly given either carprofen (2.2 mg/kg body weight, orally) or a placebo beginning 12 hours preoperatively and continuing every 12 hours for a total of three doses. The patients were assessed for postoperative pain using a subjective pain score and given oxymorphone (0.1 mg/kg body weight, intramuscularly) every four hours if the pain score was 2 or greater. Blood samples were also collected to determine serum cortisol levels. There was a significant increase in serum cortisol levels in the immediate postoperative period in both the placebo group and the carprofen group (p less than 0.05). There was no significant difference in the percentage of increase in serum cortisol levels between the two groups. No correlation was evident between the serum cortisol levels and the corresponding pain scores in either group. This subjective method of assessing postoperative pain was not accurate and should not be relied upon for determination of postoperative analgesic administration. Perioperative oral administration of carprofen did not appear to be effective in controlling postoperative pain in these patients.     

Evaluation of intravenous administration of meloxicam for perioperative pain management following stifle joint surgery in dogs

OBJECTIVE: To compare preoperative administration of meloxicam and butorphanol to perioperative administration of butorphanol alone for control of postoperative signs of pain in dogs. ANIMALS: 40 client-owned dogs scheduled for surgical repair of a cranial cruciate ligament rupture. PROCEDURE: Group-1 dogs received butorphanol (0.2 mg/kg, IV) and meloxicam (0.2 mg/kg, IV) just prior to surgery. Group-2 dogs received butorphanol just prior to surgery (0.2 mg/kg, IV) and at incision closure (0.1 mg/kg, IV). Pain assessment began 1 to 2 hours before surgery and from extubation until 24 hours after surgery by obtaining the following measurements: the visual analog scale (VAS) score, cumulative pain score (CPS), adjusted cumulative pain score, modified cumulative pain score, and the adjusted modified cumulative pain score (AMCPS). Serum cortisol concentration was measured between 12 to 24 and between 1 to 2 hours prior to surgery, and at 30 minutes, and 1, 2, 4, 8, 18, and 24 hours after extubation. RESULTS: No significant differences between treatment groups were observed in CPS or VAS score. At 8, 9, 10, and 11 hours after extubation, meloxicam-butorphanol-treated dogs had a significantly lower AMCPS, compared with butorphanol-alone-treated dogs. Total serum cortisol concentration (area under the curve) during the measurement period was significantly lower in meloxicam-butorphanol-treated dogs, compared with butorphanol-alone treated dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Preoperative single dose administration of meloxicam-butorphanol is equivalent to or slightly better than the administration of 2 perioperative doses of butorphanol for the control of postoperative signs of pain in dogs.     

Comparison of perioperative analgesic protocols for dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE: To compare effects of 3 commonly used perioperative analgesic protocols (epidural injection, intra-articular injection, and intravenous [IV] injection) for management of postoperative pain in dogs after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Prospective, randomized clinical trial. ANIMALS: Fifty-six healthy dogs with naturally occurring cranial cruciate ligament rupture. METHODS: Dogs were premedicated with IV hydromorphone and acepromazine and were randomly assigned to receive either E (preoperative epidural injection with morphine and bupivacaine), IA (pre- and postoperative intra-articular injections of bupivacaine), or C (neither epidural morphine and bupivacaine, nor intra-articular bupivacaine). All dogs were administered hydromorphone (0.05 mg/kg IV) at extubation and as needed to maintain comfort postoperatively. Patients were observed and monitored continuously for 24 hours and discomfort was assessed using visual analog pain scores (VASs), multifactorial pain scores (MPSs), and response to a pressure nociceptive threshold (PNT) measuring device. Time to 1st dose and the total doses of hydromorphone required to achieve adequate comfort for each dog were recorded. RESULTS: No differences in measured indices of postoperative pain were observed between dogs of each treatment group; VAS (P=.190), MPS (P=.371), and PNT (P=.160). Time to 1st analgesic intervention was longer for Group E compared with Group C (P=.005) and longer for Group IA compared with Group C (P=.032). Although time to 1st intervention between Groups E and IA were longer for Group E, differences were not significant. To provide an adequate level of comfort, more analgesic interventions were administered to dogs in Group C compared with dogs in group E (P=.015). On average, more hydromorphone was administered to Group C compared with Group IA (P=.072) and to Group IA compared with Group E (P=.168), but statistical significance was not reached for these data. CONCLUSIONS: In this study population, significant differences were seen in time to 1st hydromorphone dose between Groups E and IA compared with Group C. As well, more supplemental analgesia was administered to Group C compared with Group E to maintain the same level of postoperative comfort. Although differences between Groups E and IA tended to favor the epidural group, differences were minimal and not statistically significant. CLINICAL RELEVANCE: Our results suggest that regardless of analgesic protocol, measured indices of pain in dogs after TPLO can be minimized if dogs are continuously observed and appropriately supplemented with parenteral opioids. However, the frequency of postoperative opioid dosing can be minimized and may be a factor when contemplating supplementary use of epidural or intra-articular injections as part of a balanced analgesic approach.     

Comparison of carprofen and pethidine as postoperative analgesics in the cat

The postoperative analgesia and sedation in cats given carprofen (4·0 mg/kg bodyweight by subcutaneous injection preoperatively) was compared to that in cats given pethidine (3·3 mg/kg bodyweight by intramuscular injection postoperatively) in a controlled, randomised, blinded, multicentre clinical trial. Further dosing with the particular analgesic was allowed if a cat was exhibiting unacceptable pain. In total, 57 carprofen cases and 59 pethidine cases were evaluated. Significantly fewer cats in the carprofen group required additional doses of analgesic, and mean pain scores were significantly lower from four hours after ovariohysterectomy, and at 18 to 24 hours after castration, compared to the pethidine group. In conclusion, carprofen provided as good a level of postoperative analgesia as pethidine, but of a longer duration (at least 24 hours) and was well tolerated. It thus provides an option for 'pre-emptive analgesia' in cats about to undergo surgery.     

Comparison of morphine and carprofen administered alone or in combination for analgesia in dogs undergoing ovariohysterectomy

In this study the analgesic efficacy of the pure agonistic opioid morphine and the cyclo-oxygenase type-2-selective carprofen were compared since there is no previous specific comparative study for these two common analgesics. Forty-five bitches undergoing elective ovariohysterectomy were randomly assigned to one of three groups; receiving morphine 0.4 mg/kg bodyweight pre-operatively and 0.2 mg/kg every 4-6 hours thereafter (Morphine group), receiving a once-off carprofen 4 mg/kg injection (Carprofen group) or receiving both morphine and carprofen (MorphCarp group). The dogs were premedicated with acepromazine 0.01 mg/kg and induced with either thiopentone 5-10 mg/kg or propofol 4-6 mg/kg. General anaesthesia was maintained with halothane in oxygen. The degree of pain was assessed over a 24-hour period under blinded conditions using a pain scale modified from the University of Melbourne pain scale and the Glasgow composite pain tool. Physiological parameters such as respiratory rate, pulse rate and body temperature were also assessed over the same time period. There was no significant difference in pain-scores and thus analgesia offered by the three analgesia protocols at any assessment point across the three groups, but there were differences within groups across time points. Baseline total pain-scores were lower than scores at all post-operative points within all three groups. Both morphine and carprofen provided good analgesia without any obvious adverse effects. This study indicates that at the dosages indicated above, carprofen administered on its own produces analgesia equal to that produced by morphine and that the two drugs administered together do not produce better analgesia than either drug administered on its own.     

Comparison of analgesic efficacy of preoperative or postoperative carprofen with or without preincisional mepivacaine epidural anesthesia in canine pelvic or femoral fracture repair

Objective— To compare analgesic efficacy of preoperative versus postoperative administration of carprofen and to determine, if preincisional mepivacaine epidural anesthesia improves postoperative analgesia in dogs treated with carprofen. Study Design— Blind, randomized clinical study. Animals— Dogs with femoral (n=18) or pelvic (27) fractures. Methods— Dogs were grouped by restricted randomization into 4 groups: group 1=carprofen (4 mg/kg subcutaneously) immediately before induction of anesthesia, no epidural anesthesia; group 2=carprofen immediately after extubation, no epidural anesthesia; group 3=carprofen immediately before induction, mepivacaine epidural block 15 minutes before surgical incision; and group 4=mepivacaine epidural block 15 minutes before surgical incision, carprofen after extubation. All dogs were administered carprofen (4 mg/kg, subcutaneously, once daily) for 4 days after surgery. Physiologic variables, nociceptive threshold, lameness score, pain, and sedation (numerical rating scale [NRS], visual analog scale [VAS]), plasma glucose and cortisol concentration, renal function, and hemostatic variables were measured preoperatively and at various times after surgery. Dogs with VAS pain scores >30 were administered rescue analgesia. Results— Group 3 and 4 dogs had significantly lower pain scores and amount of rescue analgesia compared with groups 1 and 2. VAS and NRS pain scores were not significantly different among groups 1 and 2 or among groups 3 and 4. There was no treatment effect on renal function and hemostatic variables. Conclusions— Preoperative carprofen combined with mepivacaine epidural anesthesia had superior postoperative analgesia compared with preoperative carprofen alone. When preoperative epidural anesthesia was performed, preoperative administration of carprofen did not improve postoperative analgesia compared with postoperative administration of carprofen. Clinical Relevance— Preoperative administration of systemic opioid agonists in combination with regional anesthesia and postoperative administration of carprofen provides safe and effective pain relieve in canine fracture repair.     

Effect of deracoxib,a new COX-2 inhibitor,on the prevention of lameness induced by chemical synovitis in dogs

Twenty-four healthy, mixed-breed hound-type dogs were evenly and randomly assigned to a placebo control group, one of four dosages of deracoxib (0.3, 1, 3, or 10 mg/kg), or carprofen (2.2 mg/kg). Oral dosing of placebo, carprofen, or deracoxib was done 30 minutes before intraarticular injection of urate crystal suspension for induction of synovitis. Ground reaction forces, subjective clinical lameness scores, pain, joint effusion, and quantitative pain threshold responses were measured in a blinded fashion before induction of synovitis and 2, 4, 6, 8, 12, and 24 hours after injection. The medium and high dosages of deracoxib were effective in preventing lameness and pain associated with synovitis. Carprofen was also somewhat effective in attenuating the severity of urate-induced synovitis but to a lesser degree than the medium dose of deracoxib. Preemptive deracoxib treatment at dosages as low as 1 mg/kg reduced lameness and pain of synovitis associated with intraarticular administration of urate crystals.     

Use of a continuous, local infusion of bupivacaine for postoperative analgesia in dogs undergoing total ear canal ablation

OBJECTIVE: To determine whether addition of a continuous, local infusion of bupivacaine would improve postoperative analgesia in dogs undergoing total ear canal ablation. DESIGN: Randomized controlled trial. ANIMALS: 16 dogs undergoing total ear canal ablation (12 unilaterally and 4 bilaterally with > 1 month between procedures). PROCEDURE: Dogs were randomly allocated to receive morphine (0.25 mg/kg [0.11 mg/lb]) at the end of the procedure (10 procedures) or morphine and a continuous, local infusion of bupivacaine (0.13 to 0.21 mg/kg/h [0.06 to 0.1 mg/lb/h]; 10 procedures). Dogs were observed for 48 hours after surgery. Additional doses of morphine were administered up to every 4 hours in dogs with signs of severe pain. RESULTS: Temperament, sedation, analgesia, and cumulative pain scores were not significantly different between groups any time after surgery. Recovery score was significantly higher for dogs that received bupivacaine than for control dogs 2 hours after extubation but not at any other time. Serum cortisol concentration was not significantly different between groups at any time but, in both groups, was significantly increased at the time of extubation, compared with all other observation times. Total number of additional doses of morphine administered was not significantly different between groups. Bupivacaine was not detected in the plasma of any of the dogs that received the local bupivacaine infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that addition of a continuous, local infusion of bupivacaine did not significantly increase the degree of postoperative analgesia in dogs that underwent total ear canal ablation and were given morphine at the end of surgery.     

Effect of administration of nonsteroidal anti-inflammatory drugs before surgery on renal function in clinically normal dogs

OBJECTIVES: To investigate renal function in clinically normal dogs undergoing general anesthesia for ovariohysterectomies that received nonsteriodal antiinflammatory drugs (NSAID) before surgery. ANIMALS: 40 clinically normal dogs. PROCEDURE: After induction of anesthesia, dogs were given an analgesic. Renal function was assessed before surgery and 24 and 48 hours after surgery by means of serum urea and creatinine concentrations, fractional clearance of sodium (FC(Na)), urine gamma-glutamyltransferase (GGT) and alkaline phosphatase (ALP) activities, and urine analysis. Ten dogs in each of 4 groups received ketorolac tromethamine (0.5 mg/kg of body weight), ketoprofen (1 mg/kg), carprofen (4 mg/kg), or morphine (0.1 mg/kg; control group). RESULTS: Duration of general anesthesia ranged from 1.75 to 5 hours, with a mean of 3 hours. Two ketorolac- and 2 ketoprofen-treated dogs had transient azotemia. A significant decrease in the FC(Na) between before surgery and 24 hours after surgery, and between before surgery and 48 hours after surgery, was found in ketoprofen- and carprofen-treated dogs. Ketorolac-, ketoprofen-, and morphine-treated dogs had a decrease in urine specific gravity. Two ketorolac, 1 ketoprofen-, 1 carprofen-, and 4 morphine-treated dogs had increases in renal tubular epithelial cells on urine sediment examination 24 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: In clinically normal dogs undergoing general anesthesia and elective surgery, the use of NSAID as analgesics is not contraindicated. Compared with ketorolac or ketoprofen, carprofen had the least effect on renal function and integrity.     

A comparison between pre-operative carprofen and a long-acting sufentanil formulation for analgesia after ovariohysterectomy in dogs

OBJECTIVE: To assess the analgesic efficacy and adverse effects of a novel, long-acting sufentanil preparation in dogs undergoing ovariohysterectomy (OHE). STUDY DESIGN: Blinded, positively controlled, randomized field trial with four parallel treatment groups. ANIMALS: Eighty client owned dogs undergoing elective OHE randomly allocated into four treatment groups (each n = 20). MATERIALS AND METHODS: Three groups received intramuscular (IM) sufentanil (at 10, 15 and 25 microg kg(-1), respectively) and the control group received subcutaneous (SC) carprofen 4 mg kg(-1) SC plus acepromazine 0.05 mg kg(-1) IM as pre-anaesthetic medication. OHE was performed under thiopental/halothane anaesthesia. Visual Analogue Scale (VAS) scores for pain and sedation were awarded and mechanical nociceptive thresholds were measured at the wound and hock before surgery and up to 24 hours after tracheal extubation. Serum cortisol was measured before surgery, during surgery and up to 24 hours after tracheal extubation. Animals with inadequate post-operative analgesia were given rescue medication. RESULTS: In the carprofen group, VAS pain scores were significantly higher, wound tenderness was greater and requirement for rescue analgesia was more than in the sufentanil-treated groups. Sufentanil produced dose dependent analgesia and sedation. All treatment groups showed similar patterns of change for cortisol concentrations. Use of the sufentanil preparation was associated with a relatively high incidence of adverse events. CONCLUSIONS: The long-acting preparation of sufentanil provided excellent post-operative analgesia that was significantly better than that provided by carprofen. However, use of this formulation, in the anaesthetic technique used in the study, resulted in a relatively high incidence of adverse effects. CLINICAL RELEVANCE: Full mu (MOP) opioid agonists provide significantly better post-operative analgesia than nonsteroidal anti-inflammatory drugs after moderately painful surgery. However, the widely recognized adverse effects of opioids may preclude the use of these agents.     

The effects of preoperative oral administration of carprofen or tramadol on postoperative analgesia in dogs undergoing cutaneous tumor removal

This prospective, blinded, controlled clinical study compared the effects of pre-emptive oral administration of carprofen or tramadol on pain scores and analgesic requirement in dogs undergoing cutaneous tumor removal. Thirty-six client-owned dogs presenting for cutaneous tumor removal were randomly assigned to receive carprofen, tramadol, or no treatment prior to surgery. Pain was assessed using a visual analog scale (VAS), the Modified Glasgow Composite Measure Pain Score (MGCMPS), and algometry at enrollment, prior to premedication, at extubation, then hourly for the first 4 h, and every 4 h for 24 h. Dogs scoring ≥ 7 (MGCMPS), or having a VAS measurement ≥ 40 mm were given rescue analgesia. There were no significant differences in pain VAS, MGCMPS, or algometry. There were no differences in rescue analgesia requirement, or time to rescue analgesia among groups. Carprofen, tramadol, or no pre-emptive analgesia, combined with pre-operative hydromorphone and rescue analgesia, resulted in satisfactory analgesia in the 24-hour postoperative period.     

Comparison of the analgesic effects of meloxicam and carprofen administered preoperatively to dogs undergoing orthopaedic surgery

Thirty-two dogs undergoing operations to repair a torn cranial cruciate ligament or a fractured long bone were randomly allocated to one of two treatment groups in a study on postoperative pain. Sixteen of the dogs were given 4 mg/kg carprofen and the other 16 were given 0.2 mg/kg meloxicam subcutaneously before the operation. The signs of pain shown by the animals were assessed for 24 hours on a visual analogue scale, a discontinuous scoring system, and a score based on five behavioural and physiological variables. The dogs' heart and respiratory rates and their mean arterial blood pressures were also measured non-invasively at each assessment. Blood samples were taken before the surgery and 24 hours after it, and the concentrations of urea and creatinine were measured in plasma. Both drugs were effective in relieving the signs of pain for up to 24 hours in all the dogs. There were no significant changes in the concentrations of urea and creatinine, and no adverse effects were reported during the postoperative period.     

Carprofen as an analgesic for postoperative pain in cats: Dose titration and assessment of efficacy in comparison to pethidine hydrochloride

The aim of this study was to titrate the optimal dose of carprofen for single dose usage, for alleviating postoperative pain, under a double-blind and randomised protocol, using both negative and positive controls. Renal tolerance was assessed by screening plasma urea and creatinine. Pre- and postoperative assessment of pain and sedation was made using a dynamic and interactive visual analogue scoring system in 60 cats undergoing ovariohysterectomy. The cats were randomly assigned to one of six groups: (1) carprofen at 1-0 mg/kg subcutaneously (sc); (2) carprofen at 2-0 mg/kg sc; (3) carprofen at 4-0 mg/kg sc; (4) pethidine at 5-0 mg/kg intramuscularly (im), (5) pethidine at 10-0 mg/kg im; and (6) no analgesics (injection of saline). All injections were given postoperatively on tracheal extuba-tion and administered in a double-blind manner. Assessments were made up to 20 hours post extubation. Prior to induction and at 20 hours post extubation, blood samples were taken for laboratory analysis of the urea and creatinine content to check for any adverse effect on renal function. Cats given pethidine did not appear more sedated than the groups receiving carprofen or saline. Cats receiving carprofen were in less pain postoperatively overall, with 4-0 mg/kg being the most effective dose rate (significantly better than the other doses of carprofen at four and eight hours post extubation). The highest dose of pethidine provided significantly better analgesia than the highest dose of carprofen up to two hours post extubation, but from two to 20 hours post extubation carprofen at 4-0 mg/kg provided significantly better analgesia than the pethidine. None of the analgesic regimens appeared to affect renal function adversely, as measured by urea and creatinine levels.     

Effects of two doses of buprenorphine four or six hours apart on nociceptive thresholds, pain and sedation in dogs after castration

Twenty-eight dogs were randomly allocated into two groups. They were premedicated with either 10 or 20 microg/kg buprenorphine and 0.05 mg/kg acepromazine administered intramuscularly, and then anaesthetised with intravenous thiopentone to effect and maintained with isoflurane in 100 per cent oxygen. The dogs underwent routine castration, and a second dose of 10 microg/kg buprenorphine was administered four hours after the first or 20 microg/kg six hours after the first dose. Levels of pain and sedation were scored on a visual analogue scale and in terms of the dogs' requirement for rescue analgesia, and mechanical nociceptive thresholds were measured at the hock and wound at premedication and one, two, three, four, five, six, seven, 10 and 21 to 22 hours later. Pain scores were low in both groups, with a trend for lower scores in the high dose group; administration of the second dose of buprenorphine further decreased the pain scores. Buprenorphine produced good preoperative sedation and the level of sedation decreased over time after surgery. Administration of the second high dose of buprenorphine did not increase the level of sedation. Both doses of buprenorphine prevented hyperalgesia at the wound and hock postoperatively. Three dogs given the low dose and one dog given the high dose required rescue analgesia with carprofen.     

Comparison of postoperative pain after ovariohysterectomy by harmonic scalpel-assisted laparoscopy compared with median celiotomy and ligation in dogs

OBJECTIVE: To compare the effects of postoperative pain after ovariohysterectomy by harmonic scalpel-assisted laparoscopy (HALO) and traditional ovariohysterectomy (OVH) in dogs. STUDY DESIGN: A randomized, blinded, prospective study. SAMPLE POPULATION: Sixteen, purpose-bred, intact female, Beagle dogs. METHODS: Dogs were divided into 2 groups: Group 1 (8 dogs), which had OVH by HALO, and Group 2 (8 dogs), which had traditional OVH. Physiologic data, abdominal nociceptive threshold scores, and University of Melbourne pain scores (UMPS) were recorded at 2, 6, 12, 24, 48, and 72 hours after surgery. Blood samples for measurement of plasma cortisol, glucose, and creatine phosphokinase (CPK) concentrations were collected at the time of the incision, and 2, 6, 12, 24, 48, and 72 hours after surgery. RESULTS: No significant surgical complications occurred. The HALO mean surgical time was significantly longer (55.7 minutes) than traditional OVH (31.7 minutes). No significant differences were observed between groups for the pain measures of heart rate, respiratory rate, temperature, CPK, and glucose concentrations. The OVH group had significantly higher mean plasma cortisol levels at hour 2 after surgery than the HALO group (P=.0001). The mean UMPS were significantly higher in OVH than the HALO group at all postoperative times (P=.0001). The mean nociceptive threshold measurements revealed significantly higher tolerated palpation pressures in HALO than OVH at all postoperative times, except hour 72 (P=.0002). CONCLUSIONS: Dogs appeared to be in less pain with HALO than OVH. The harmonic scalpel coagulated ovarian and uterine vessels completely with minimal collateral damage to surrounding tissues. CLINICAL RELEVANCE: HALO is a safe alternative to OVH and offers a minimally invasive and less painful method of surgery.     

Safety and efficacy of preoperative administration of meloxicam, compared with that of ketoprofen and butorphanol in dogs undergoing abdominal surgery

OBJECTIVE: To compare the safety and efficacy of preoperative administration of meloxicam with that of ketoprofen and butorphanol in dogs undergoing abdominal surgery. ANIMALS: 36 dogs undergoing laparotomy, splenectomy, or cystotomy. PROCEDURE: Dogs were randomly assigned to 1 of 3 groups. In the first part of the study, dogs were given a single dose of meloxicam, ketoprofen, or a placebo, and buccal mucosal bleeding times were measured. In the second part of the study, dogs were given meloxicam, ketoprofen, or butorphanol prior to surgery. Dogs in the butorphanol group received a second dose immediately after surgery. Pain scores (1 to 10) were assigned hourly for 20 hours after surgery and used to determine an overall efficacy score for each dog. Dogs with a pain score > or =3 were given oxymorphone for pain. Dogs were euthanatized 8 days after surgery, and gross and histologic examinations of the liver, kidneys, and gastrointestinal tract were conducted. RESULTS: Overall efficacy was rated as good or excellent in 9 of the 12 dogs that received meloxicam, compared with 9 of the 12 dogs that received ketoprofen and only 1 of the 12 dogs that received butorphanol. No clinically important hematologic, biochemical, or pathologic abnormalities were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that preoperative administration of meloxicam is a safe and effective method of controlling postoperative pain for 20 hours in dogs undergoing abdominal surgery; the analgesic effects of meloxicam were comparable to those of ketoprofen and superior to those of butorphanol.