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.     

Use of low doses of ketamine administered by constant rate infusion as an adjunct for postoperative analgesia in dogs

OBJECTIVE: To compare indicators of postoperative pain and behavior in dogs with and without a low-dose ketamine infusion added to usual perioperative management. DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: 27 dogs undergoing forelimb amputation. PROCEDURE: Dogs were anesthetized with glycopyrrolate, morphine, propofol, and isoflurane. Thirteen dogs were treated with ketamine IV, as follows: 0.5 mg/kg (0.23 mg/lb) as a bolus before surgery, 10 microg/kg/min (4.5 microg/lb/min) during surgery, and 2 microg/kg/min (0.9 microg/lb/min) for 18 hours after surgery. Fourteen dogs received the same volume of saline (0.9% NaCl) solution. All dogs received an infusion of fentanyl (1 to 5 microg/kg/h [0.45 to 2.27 pg/lb/h]) for the first 18 hours after surgery. Dogs were evaluated for signs of pain before surgery, at the time of extubation, and 1, 2, 3, 4, 12, and 18 hours after extubation. Owners evaluated their dogs' appetite, activity, and wound soreness on postoperative days 2, 3, and 4. RESULTS: Dogs that received ketamine infusions had significantly lower pain scores 12 and 18 hours after surgery and were significantly more active on postoperative day 3 than dogs that received saline solution infusions. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that perioperative administration of low doses of ketamine to dogs may augment analgesia and comfort in the postoperative surgical period.     

The effects of epidural deracoxib on the ground reaction forces in an acute stifle synovitis model

OBJECTIVE: To evaluate the efficacy of epidurally administered deracoxib to mediate the signs of a sodium urate crystal-induced stifle synovitis in dogs, and to compare the efficacy of epidural versus subcutaneously administered deracoxib. STUDY DESIGN: Experimental, randomized, blinded, placebo-controlled modified cross-over design. ANIMALS: Random source, adult, mixed breed dogs (n = 24; 14 males, 10 females). METHODS: Sodium urate crystals were used to create a stifle synovitis model to evaluate the efficacy of deracoxib. Dogs were divided into 4 groups: 3 mg/kg epidural deracoxib, 1.5 mg/kg epidural deracoxib, 3 mg/kg subcutaneous deracoxib, and a placebo (vehicle for deracoxib). Force plate and subjective evaluations were made at time 0, 2, 4, 8, 12, and 24 hours post-treatment. Repeated measures ANOVA with Bonferroni-corrected post hoc comparisons was used to determine significant treatment effects. RESULTS: Peak vertical force (PVF) and vertical impulse (VI) were both significantly higher in deracoxib treated dogs compared with placebo. For 3 mg/kg epidural and subcutaneous deracoxib, PVF and VI were significantly greater than for 1.5 mg/kg epidural deracoxib. Overall pain score for all deracoxib-treated dogs was significantly lower than for placebo dogs. CONCLUSIONS: Epidural administration of deracoxib is effective at providing analgesia in an acute joint pain model; however, it does not appear to be more effective than systemic administration. CLINICAL RELEVANCE: Injectable deracoxib is effective in providing analgesia in acute inflammatory conditions of synovial joints.     

Comparison of opioid and alpha-2 adrenergic receptor location and density in the horse and dog using radioligand binding

Ketamine, a noncompetitive NMDA receptor antagonist, has been shown to provide analgesia in some species. To target the NMDA receptor specifically and to potentially minimize some untoward side-effects, ketamine had been used epidurally. The objective of this study was to determine the analgesic effect of epidurally administered ketamine in dogs with chemically induced synovitis.
Sixteen healthy dogs were used. Dogs were anesthetized with propofol (4 mg kg⁻¹ IV). Synovitis was induced by injecting 1 mL of sodium urate crystal solution (10 mg mL⁻¹) into the right stifle. Dogs were allowed to recover and the synovitis was allowed to develop for 12 hours. The dogs were then anesthetized again using propofol (4 mg kg⁻¹ IV). Lumbosacral epidural injections were performed with each dog receiving either 2 mg kg⁻¹ of ketamine (20 mg mL⁻¹) or an equal volume of placebo (sterile water containing not more than 0.1 mg mL⁻¹ benzethonium chloride). Analgesia was assessed at baseline and then at 12, 14, 16, 18, 20, and 24 hours after induction of synovitis. Ground reaction forces (peak vertical force and impulse area) and overall pain were measured using a force platform and a pain scoring system (numerical rating scale).
Analysis of the data by Repeated Measures anova showed that the dogs developed a significant lameness between the baseline and 12 hours. However, no significant difference in ground reaction forces or total pain score was demonstrated between the treatment and control groups at any other time.
In conclusion, ketamine administered epidurally at a dose of 2 mg kg⁻¹ did not provide significant analgesia in dogs with chemically induced synovitis.     

Concentrations of cartilage oligomeric matrix protein in dogs with naturally developing and experimentally induced arthropathy

OBJECTIVE: To assay concentrations of cartilage oligomeric matrix protein (COMP) in canine sera and synovial fluid (SF), to compare COMP concentrations in clinically normal dogs and dogs with joint disease, and to analyze changes in COMP concentrations in dogs with experimentally induced acute synovitis. ANIMALS: 69 control dogs without joint disease, 23 dogs with naturally occurring aseptic arthropathy, and 6 dogs with experimentally induced synovitis. PROCEDURE: Serum (n = 69) and SF (36) were obtained from control dogs. Samples of serum (n = 23) and SF (13) were obtained from dogs with naturally occurring aseptic arthropathy with or without radiographic features of osteoarthritis (OA). Serum and SF were obtained before and 1, 2, 3, and 7 days after induction of synovitis. The COMP concentrations were determined by use of an inhibition ELISA that had canine cartilage COMP and monoclonal antibody against human COMP. RESULTS: Concentrations of COMP in serum and SF of control dogs were 31.3+/-15.3 and 298.7+/-124.7 microg/ml, respectively. In naturally occurring OA, COMP concentrations in serum (44.9+/-177 microg/ml) and SF (401.7+/-74.3 microg/ml) were significantly higher than corresponding concentrations in control dogs. The COMP concentration in SF peaked 24 and 48 hours after induction of synovitis, whereas concentration in serum peaked on day 3. CONCLUSIONS AND CLINICAL RELEVANCE: These results supported the hypothesis that COMP concentration in serum and SF of dogs may be altered after cartilage degradation or synovitis. Measurement of COMP concentrations can be useful when differentiating arthropathies in dogs.     

Cardiorespiratory responses and plasma cortisol concentrations in dogs treated with medetomidine before undergoing ovariohysterectomy

OBJECTIVE: To evaluate effects of medetomidine on anesthetic dose requirements, cardiorespiratory variables, plasma cortisol concentrations, and behavioral pain scores in dogs undergoing ovariohysterectomy. DESIGN: Randomized, prospective study. ANIMALS: 12 healthy Walker-type hound dogs. PROCEDURE: Dogs received medetomidine (40 micrograms/kg [18.2 micrograms/lb] of body weight, i.m.; n = 6) or saline (0.9% NaCl) solution (1 ml, i.m.; 6) prior to anesthesia induction with thiopental; thiopental dose needed for endotracheal intubation was compared between groups. Ovariohysterectomy was performed during halothane anesthesia. Blood samples were obtained at various times before drug administration until 300 minutes after extubation. Various physiologic measurements and end-tidal halothane concentrations were recorded. RESULTS: In medetomidine-treated dogs, heart rate was significantly lower than in controls, and blood pressure did not change significantly from baseline. Plasma cortisol concentrations did not increase significantly until 60 minutes after extubation in medetomidine-treated dogs, whereas values in control dogs were increased from time of surgery until the end of the recording period. Control dogs had higher pain scores than treated dogs from extubation until the end of the recording period. CONCLUSION AND CLINICAL RELEVANCE: Administration of medetomidine reduced dose requirements for thiopental and halothane and provided postoperative analgesia up to 90 minutes after extubation. Dogs undergoing ovariohysterectomy by use of thiopental induction and halothane anesthesia benefit from analgesia induced by medetomidine administered prior to anesthesia induction. Additional analgesia is appropriate 60 minutes after extubation.     

Analgesic effects of epidurally administered levogyral ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy

OBJECTIVE: To evaluate the analgesic and adverse effects of epidurally administered levogyral (S[+]) ketamine alone or in combination with morphine on intraoperative and postoperative pain in dogs undergoing ovariohysterectomy. ANIMALS: 30 dogs scheduled for ovariohysterectomy. PROCEDURE: Dogs were randomly allocated to 1 of 3 groups. Dogs in group 1 received S(+) ketamine (1 mg/kg), dogs in group 2 received S(+) ketamine (0.5 mg/kg) and morphine (0.05 mg/kg), and dogs in group 3 received S(+) ketamine (1 mg/kg) and morphine (0.025 mg/kg). The skin was incised 15 minutes after epidural administration of analgesics. Heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), oxygen saturation as measured by pulse oximetry, and arterial blood gases were obtained before anesthesia, 15 minutes after epidural administration of analgesics, 15 and 30 minutes after initiation of surgery, and at the end of surgery. During the intraoperative period, an increase of > or =20% in baseline values for HR, RR, and SBP was considered a sign of intraoperative pain. Signs of pain and adverse effects were assessed at 2, 4, and 8 hours postoperatively. RESULTS: There were no significant differences in intraoperative or postoperative measurements among the 3 groups. No dogs had intraoperative signs of pain. Mean postoperative pain assessment scores were <3.5 in all 3 groups. Salivation was the most frequent adverse effect in dogs in groups 1 and 3, and sedation occurred more frequently in dogs in groups 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE: All 3 analgesic regimens provided good respiratory and cardiovascular stability intraoperatively and adequate postoperative analgesia with minimal adverse effects.     

Comparison of preoperative carprofen and postoperative butorphanol as postsurgical analgesics in cats undergoing ovariohysterectomy

OBJECTIVE: To compare carprofen to butorphanol, with regard to postsurgical analgesic effects, duration of analgesia, and adverse side effects. STUDY DESIGN: Blinded, randomized clinical study. ANIMALS: Seventy-one cats, 0.5-5 years of age, weighing 3.24 +/- 0.61 kg, undergoing ovariohysterectomy (OHE). METHODS: Cats were premedicated with subcutaneous atropine (0.04 mg kg(-1)), acepromazine (0.02 mg kg(-1)), and ketamine (5 mg kg(-1)). Anesthesia was induced with ketamine (5 mg kg(-1)) and diazepam (0.25 mg kg(-1)) given intravenously, and maintained with isoflurane. There were three treatment groups: group C (4 mg kg(-1) carprofen SC at induction), group B (0.4 mg kg(-1) butorphanol SC at end of surgery), and group S (0.08 mL kg(-1) of sterile saline SC at induction and end of surgery). Behavioral data were collected using a composite pain scale (CPS), prior to surgery (baseline) and 1, 2, 3, 4, 8, 12, 16, 20, and 24 hours post-surgery. Interaction scores were analyzed separately. Cats with CPS scores >12 received rescue analgesia (meperidine, 4 mg kg(-1), intramuscular). RESULTS: Sixty cats completed the study. The CPS scores did not differ significantly between groups C and B at any time period. CPS scores for groups B and C were significantly increased for 12 hours post-surgery, and in group S for 20 hours. Both group C and B CPS scores were significantly lower than group S in this 20-hour postoperative period, except at 4 hours (B and C) and at 3 and 8 hours (B alone). Interaction scores for group C returned to preoperative baseline 4 hours after surgery, while both groups B and S remained increased for at least 24 hours post-surgery. Nine cats required meperidine. CONCLUSION: In this study, carprofen provided better postsurgical analgesia than butorphanol. Clinical relevance Neither drug completely abolished pain, however preoperative carprofen provided better pain control compared with postoperative butorphanol in the 24-hour period following OHE surgery in cats.     

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.     

Scintigraphic evaluation of dogs with acute synovitis after treatment with glucosamine hydrochloride and chondroitin sulfate

OBJECTIVE: To evaluate the effects of orally administered glucosamine hydrochloride (GlAm)-chondroitin sulfate (CS) and GlAm-CS-S-adenosyl-L-methionine (SAMe) on chemically induced synovitis in the radiocarpal joint of dogs. ANIMALS: 32 adult mixed-breed dogs. PROCEDURE: For 21 days, all dogs received a sham capsule (3 groups) or GlAm-CS (prior treatment group) in a double-blinded study. Unilateral carpal synovitis was induced by injecting the right radiocarpal joint with chymopapain and the left radiocarpal joint (control joint) with saline (0.9% NaCl) solution. Joints were injected on alternate days for 3 injections. After induction of synovitis, 2 groups receiving sham treatment were given GlAm-CS or GlAm-CS-SAMe. Another group continued to receive sham capsules (control group). Joint inflammation was quantified, using nuclear scintigraphy, before injection of joints and days 13, 20, 27, 34, 41, and 48 after injection. Lameness evaluations were performed daily. RESULTS: Dogs given GlAm-CS before induction of synovitis had significantly less scintigraphic activity in the soft-tissue phase 48 days after joint injection, significantly less uptake in the bone phase 41 and 48 days after joint injection, and significantly lower lameness scores on days 12 to 19, 23, and 24 after injection, compared with other groups. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of this study suggest that prior treatment with GlAm-CS for 21 days had a protective effect against chemically induced synovitis and associated bone remodeling. Prior treatment with GlAm-CS also reduced lameness in dogs with induced synovitis.     

Efficacy of tolfenamic acid and meloxicam in the control of postoperative pain following ovariohysterectomy in the cat

Objective The hypothesis was that Visual Analog Scale (VAS) scores would be lower, and mechanical wound thresholds (MWT) higher, in cats receiving tolfenamic acid compared to those receiving placebo in the postoperative period following elective ovariohysterectomy. Animals Sixty‐nine client‐owned cats. Methods A prospective, randomized, blinded and placebo‐controlled study was performed in cats which underwent ovariohysterectomy following preoperative tolfenamic acid, meloxicam, or placebo. A second dose of the same analgesic was administered 24 hours postoperatively. Assessments were made 1‐hour before induction and 1, 2, 4, 6, 22, and 25 hours postoperatively. Pain was assessed by a blinded observer using Numerical Rating (NRS) and VAS scales. The MWT were measured using a force‐measuring device. Group comparison was performed by using one‐way anova and chi‐squared test for qualitative and quantitative data, respectively, and a mixed model for repeated measurements (p < 0.05). Results Sixty‐five cats were included in the study. There were no differences between groups at baseline. There was a treatment effect on the NRS scores at 6, 22 and 25 hours. The meloxicam group was less painful than controls at 6 and 22 hours; both treatment groups were less painful than controls at 25 hours. There were no differences between groups in VAS for pain or sedation. The number of animals receiving rescue analgesia did not differ between groups. There was a treatment effect on MWT; thresholds in both treatment groups were significantly higher than that observed in controls at all time points. Conclusions Preoperative tolfenamic acid or meloxicam reduced wound sensitivity following ovariohysterectomy in the cat. Clinical relevance Tolfenamic acid and meloxicam administered preoperatively provided a similar analgesic effect in the postoperative period lasting 24 hours. Mechanical thresholds may be a better way of evaluating postoperative analgesia provided by nonsteroidal anti‐inflammatory drugs in cats.     

The effects of local anaesthetic solution in the navicular bursa of horses with lameness caused by distal interphalangeal joint pain

REASONS FOR PERFORMING STUDY: Analgesia of the palmar digital (PD) nerves has been demonstrated to cause analgesia of the distal interphalangeal (DIP) joint as well as the sole. Because the PD nerves lie in close proximity to the navicular bursa, we suspected that that analgesia of the navicular bursa would anaesthetise the PD nerves, which would result in analgesia of the DIP joint. OBJECTIVES: To determine the response of horses with pain in the DIP joint to instillation of local anaesthetic solution into the navicular bursa. METHODS: Lameness was induced in 6 horses by creating painful synovitis in the DIP joint of one forefoot by administering endotoxin into the joint. Horses were videorecorded while trotting, before and after induction of lameness, at three 10 min intervals after instilling 3.5 ml local anaesthetic solution into the navicular bursa and, finally, after instilling 6 ml solution into the DIP joint. Lameness scores were assigned by grading the videorecorded gaits subjectively. RESULTS: At the 10 and -20 min observations, median lameness scores were not significantly different from those before administration of local anaesthetic solution into the navicular bursa (P > or = 0.05), although lameness scores of 3 of 6 horses improved during this period, and the 20 min observation scores tended toward significance (P = 0.07). At the 30 min observation, and after analgesia of the DIP joint, median lameness scores were significantly improved (P < or = 0.05). CONCLUSIONS: These results indicate that pain arising from the DIP joint can probably be excluded as a cause of lameness, when lameness is attenuated within 10 mins by analgesia of the navicular bursa. POTENTIAL RELEVANCE: Pain arising from the DIP joint cannot be excluded as a cause of lameness when lameness is attenuated after 20 mins after analgesia of the navicular bursa.     

In vitro effects and in vivo efficacy of a novel cyclooxygenase-2 inhibitor in dogs with experimentally induced synovitis

OBJECTIVE: To determine cyclooxygenase-2 (COX-2) selectivity, pharmacokinetic properties, and in vivo efficacy of ML-1,785,713 in dogs. ANIMALS: 21 healthy male and female mixed-breed dogs and 24 healthy male Beagles. PROCEDURE: Selectivity of ML-1,785,713 for inhibiting COX-2 was determined by comparing the potency for inhibiting cyclooxygenase-1 (COX-1) with that of COX-2 in canine blood. Pharmacokinetic properties were determined after i.v. (2 mg/kg) and oral (8 mg/kg) administration in female mixed-breed dogs. In vivo efficacy was evaluated in male mixed-breed dogs with urate crystal-induced synovitis. Prophylactic efficacy was evaluated by administering ML-1,785,713 two hours before induction of synovitis whereas therapeutic efficacy was determined by administering ML-1,785,713 one hour after induction of synovitis. RESULTS: Blood concentrations that resulted in 50% inhibition of COX-1 and COX-2 activity in vitro were 119.1 microM and 0.31 microM, respectively, and selectivity ratio for inhibiting COX-2 relative to COX-1 was 384. ML-1,785,713 had high oral bioavailability (101%), low systemic clearance (77 mL/min/kg), and an elimination half-life of 5.9 hours. ML-1,785,713 was efficacious when administered prophylactically and therapeutically to dogs with urate crystal-induced synovitis. CONCLUSIONS AND CLINICAL RELEVANCE: ML-1,785,713 is a novel, potent COX-2 inhibitor that is the most selective COX-2 inhibitor described for use in dogs to date. ML-1,785,713 has oral bioavailability and low systemic clearance that is comparable to other non-steroidal anti-inflammatory drugs. It is effective after prophylactic and therapeutic administration in attenuating lameness in dogs with urate crystal-induced synovitis. Drugs that specifically inhibit COX-2 and not COX-1 at therapeutic doses may have an improved tolerability profile, compared with nonselective non-steroidal anti-inflammatory drugs.     

Effect of intraperitoneal or incisional bupivacaine on pain and the analgesic requirement after ovariohysterectomy in dogs

ObjectiveTo compare the effect of intraperitoneal (IP) or incisional (INC) bupivacaine on pain and the analgesic requirement after ovariohysterectomy in dogs.Study designProspective, randomized clinical study.AnimalsThirty female dogs undergoing ovariohysterectomy (OHE).MethodsDogs admitted for elective OHE were anesthetized with acepromazine, butorphanol, thiopental and halothane. Animals were randomly assigned to one of three groups (n = 10 per group). The treatments consisted of preincisional infiltration with saline solution (NaCl 0.9%) or bupivacaine with epinephrine and/or IP administration of the same solutions, as follows: INC and IP 0.9% NaCl (control group); INC 0.9% NaCl and IP bupivacaine (5 mg kg^?1, IP group); INC bupivacaine (1 mg kg^?1) and IP 0.9% NaCl (INC group). Postoperative pain was evaluated by a blinded observer for 24 hours after extubation by means of a visual analog scale (VAS) and a numeric rating scale (NRS). Rescue analgesia (morphine, 0.5 mg kg^?1, IM) was administered if the VAS was >5/10 or the NRS >10/29.ResultsAt 1 hour after anesthesia, VAS pain scores were [medians (interquartile range)]: 6.4 (3.1–7.9), 0.3 (0.0–2.6) and 0.0 (0.0–7.0) in control, IP and INC groups, respectively. VAS pain scores were lower in the IP compared to the control group. Over the first 24 hours, rescue analgesia was administered to 7/10, 5/10 and 3/10 dogs of the control, INC and IP groups, respectively. Total number of dogs given rescue analgesia over the first 24 hours did not differ significantly among groups.Conclusions and clinical relevanceIntraperitoneal bupivacaine resulted in lower pain scores during the first hour of the postoperative period and there was a trend towards a decreased need for rescue analgesia after OHE in dogs.     

Postoperative analgesia in dogs receiving epidural morphine plus medetomidine

This investigation was carried out to compare the postoperative analgesia and plasma morphine concentrations in dogs given epidural morphine or epidural morphine combined with medetomidine prior to surgery. Twelve dogs (seven males and five females) with ruptured cranial cruciate ligaments presented to the Washington State University Veterinary Teaching Hospital. Six dogs received an epidural injection of morphine (0.1 mg/kg) and six dogs received epidural morphine (0.1 mg/kg) combined with medetomidine (0.005 mg/kg). Numeric rating scale (NRS) pain scores and cumulative pain scores (CPS) were assigned to 10-min segments of video. Video segments, heart rates and respiratory rates were recorded prior to premedication and at 4, 8, 12, 18 and 24 h after epidural injection. Blood was sampled from the cephalic vein at each of these times and during anesthesia at 0.5, 1, 2 and 3 h after epidural injection. Data were analyzed using either Friedman's test or one-way anova for repeated measures. In the morphine group, significant increases compared with premedication values were detected at 4, 8 and 12 h after epidural injection for NRS and at 4 and 12 h after epidural injection for CPS. In the morphine plus medetomidine group, NRS was significantly higher at 4 and 8 h whereas there were no differences from baseline values for CPS. Plasma morphine concentrations were not significantly different between treatment groups, but were significantly increased compared with preinjection values at 0.5, 1, 12, 18, and 24 h in the morphine plus medetomidine group. Epidurally administered morphine combined with medetomidine was associated with only minor benefits based on subjective pain scoring when compared with morphine alone in these dogs undergoing repair of a ruptured cranial cruciate ligament.     

Effects of perioperative saphenous and sciatic nerve blocks,lumbosacral epidural or morphine–lidocaine–ketamine infusion on postoperative pain and sedation in dogs undergoing tibial plateau leveling osteotomy

ObjectiveTo compare the quality of postoperative analgesia and sedation after preoperative saphenous and sciatic nerve blockade, preoperative lumbosacral epidural injection and perioperative intravenous (IV) morphine, lidocaine and ketamine infusions in dogs undergoing stifle arthroscopy and tibial plateau leveling osteotomy (TPLO) under general anesthesia.Study designProspective, blinded, randomized, clinical comparison study.AnimalsA total of 45 dogs weighing 33.9 (15.9–56.7) kg and aged 5.2 (1.0–12.0) years, mean (range), undergoing elective unilateral TPLO for spontaneous cranial cruciate ligament rupture.MethodsClient-owned dogs were enrolled. Dogs were randomly assigned to one of three groups: group MLK, perioperative IV morphine, lidocaine and ketamine infusion; group EPID, lumbosacral epidural with ropivacaine and morphine; or group SSNB, saphenous and sciatic nerve blockade with ropivacaine. Routine stifle arthroscopy followed by TPLO surgery was performed. Sedation and pain scores were assessed at 0, 2, 4, 8 and 24 hours following extubation. Rescue analgesia was administered as prescribed by Glasgow composite pain score–short form score >5.ResultsSedation scores for MLK were higher than EPID and SSNB. Pain scores for SSNB were lower than those for EPID and MLK. No significant differences were found in anesthesia duration or surgery duration among groups. No dogs required rescue analgesia.Conclusions and clinical relevanceAlthough analgesia was adequate in all groups, the best combination of analgesia without increased sedation was recorded for SSNB.     

Effects of preoperative epidural administration of racemic ketamine for analgesia in sheep undergoing surgery

OBJECTIVE: To investigate the effects of preoperative epidural administration of racemic ketamine to provide analgesia in sheep undergoing experimental hind limb orthopedic surgery. ANIMALS: 12 adult sheep (weight range, 51.4 to 67.2 kg). PROCEDURE: Sheep were anesthetized with guaifenesin, thiopental, and isoflurane; after induction of anesthesia, sheep received a lumbosacral epidural injection of ketamine (1 mg/kg; n = 6) or saline (0.9% NaCl) solution (1 mL/7 kg; 6 [control group]). Respiratory and cardiovascular variables were recorded before and at intervals during and for 6 hours after anesthesia. During that 6-hour postoperative period, analgesia was evaluated subjectively with a numeric ranking scale that included assessments of comfort, posture, movement, and response to wound palpation; buprenorphine was administered when a score > 3 (maximum score, 10) was achieved. Rectal temperature, heart and respiratory rates, and lameness were evaluated daily for 2 weeks after surgery. RESULTS: At all evaluations, cardiovascular and respiratory variables were comparable between the 2 groups. Compared with control sheep, time to first administration of rescue analgesic was significantly longer and total dose of buprenorphine administered during the 6- hour postoperative period was significantly decreased for ketamine-treated sheep. During the second week following surgery, ketamine-treated sheep had significantly less lameness than control sheep. CONCLUSIONS AND CLINICAL RELEVANCE: In sheep undergoing hind limb surgery, preoperative epidural administration of ketamine appears to provide analgesia in the immediate postoperative period and has residual analgesic effects, which may contribute to more rapid return of normal function in surgically treated limbs.     

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.     

Comparison of analgesia provided by lidocaine, lidocaine-morphine or lidocaine-tramadol delivered epidurally in dogs following orchiectomy

ObjectiveTo evaluate and compare the postoperative analgesia provided by epidural lidocaine, lidocaine/morphine or lidocaine/tramadol in dogs following elective orchiectomy.Study designProspective experimental trial.AnimalsThirty-six mongrel dogs aged 2-8 years old, weighing 6.6-22 kg.MethodsThe dogs received 6.0 mg kg^?1 of lidocaine combined with 1.0 mg kg^?1 of tramadol, 0.1 mg kg^?1 of morphine or 0.01 mL kg^?1 of 0.9% NaCl epidurally. Analgesia was assessed at 4, 8, 12, 18 and 24 hours (T4, T8, T12 and T24) after the offset of lidocaine using a scale composed of physiologic and behavioral parameters. Rescue analgesia with morphine (0.2 mg kg^?1, IM) was performed if the evaluation score exceeded 10 during the postoperative period. The scores over time were analyzed using the Friedman’s two-way analysis of variance and the comparison between groups was made by the Kruskal-Wallis test with statistical significances accepted if p = 0.05.ResultsThere were no differences in the pain scores between the morphine and tramadol groups over time and no rescue analgesia was administered. In the NaCl group, rescue analgesia was needed at T4, T8 and T12. Within this group, the final evaluation times (T18 and T24) had lower pain scores than at T4, T8 and T12.Conclusions and clinical relevanceEpidural lidocaine/tramadol provided an analgesic effect comparable to that of epidural lidocaine/morphine during the first 12 hours after surgical castration without substantial side effects, suggesting that tramadol may be an effective postoperative analgesic in dogs submitted to this surgical procedure.