Evaluation of equine radial and median nerve conduction velocities

Eleven ponies and 13 horses were used to develop a technique for determining conduction velocity for the radial and median nerves and establishing normal limits for these values. One pony was euthanatized to determine the course of the radial and the median nerves. From this dissection, both proximal and distal stimulation sites for the radial and the median nerves were selected, as well as areas for recording muscle evoked responses from the abductor digiti I longus (extensor carpi obliquus) and the radial head of the deep digital flexor muscles. The other ten ponies and the horses were used in studies on the stimulation of the nerves and recording of muscle evoked responses from which conduction velocity could be calculated. Conduction velocities for the radial and the median nerves were calculated and recorded.     

F-wave latency and F-wave conduction velocity for the tibial nerve in clinically normal dogs

OBJECTIVE: To establish a method of F-wave examinations and to determine values of F-wave conduction velocity (FWCV) and F-wave latency for the tibial nerve of clinically normal dogs. ANIMALS: 21 clinically normal dogs. PROCEDURE: The F-waves were elicited from the interosseous muscles via stimulation of the tibial nerve. The FWCV was determined by using the F-wave shortest value and the surface distance corresponding to the tibial nerve length. Correlation between the smallest latency value of the F-wave and the length of the tibial nerve and between the FWCV and rectal temperature were closely examined. RESULTS: F-wave latency was proportional to the length of the tibial nerve (correlation coefficient, 0.929). Mean +/- SD FWCV was 77.98 +/- 8.62 m/s. Regression equation was as follows: F-wave latency = 2.799 + (0.029 X length of the tibial nerve).The FWCV was increased when the measured rectal temperature was high. Correlation coefficient between FWCV and rectal temperature was 0.665. CONCLUSIONS AND CLINICAL RELEVANCE: In the study reported here, we established a reliable method for clinical evaluation of the F-wave. When assessing nerve conduction velocity, it is essential to measure nerve length along the pathway that the nerve impulse travels. This method of F-wave examination is a useful diagnostic tool for the evaluation of suspected dysfunction of the peripheral nervous system.     

Normal blood-gas values in lambs during neonatal development and in adult sheep.

Arterial oxygen (PaO2) and carbon dioxide (PaCO2) tensions and pH were determined in 20 lambs during development from two weeks to five months of age and in 34 adult sheep. Throughout the period the lambs' mean PaCO2 (33.1 mm Hg) and pH (7.46) values were similar to those determined in the adult sheep (PaCO232.1 mm Hg; pH 7.48). The lamb's mean PaO2 increased from 63.3 mm Hg at two weeks of age to about 80 mm Hg at eight weeks and by 20 weeks was similar to the mean PaO2 (88.0 mm Hg) of adult sheep.     

Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the dog: Tissue temperature-dependent reference ranges

Sensory nerve conduction velocities in the cutaneous afferents of the ulnar and peroneal nerves of the neurologically normal adult dog were determined by stimulation at stimulus intensities of 15, 20 and 25 V through subcutaneously placed electrodes and by the averaged evoked response technique. Stimulus intensities of 15 V for the ulnar nerve and 20 V for the peroneal nerve were adequate to measure the sensory nerve conduction velocities of these nerves. A linear relationship was seen between sensory nerve conduction velocity (y in m/s) and tissue temperature (x in °C) and the regression equations were expressed as follows: y=1.6x+12.3 at a stimulus intensity of 15 V for the ulnar nerve and y=2.0x–10.6 at 20 V for the peroneal nerve, respectively. The 95% confidence limits of the regressions of the sensory nerve conduction velocities against tissue temperature, obtained at a stimulus intensity of 15 V for the ulnar nerve or at a stimulus intensity of 20 V for the peroneal nerve, were proposed for a tissue temperature-dependent reference range to enable the clinician to evaluate graphically the sensory nerve conduction velocity in a diseased dog.     

F-wave conduction velocity, persistence, and amplitude for the tibial nerve in clinically normal cats

OBJECTIVE: To establish a method of F-wave evaluation and to determine normative values of F-wave parameters, including F-wave conduction velocity, persistence, and amplitude for the tibial nerve in cats. ANIMALS: 30 clinically normal cats. PROCEDURES: F-waves elicited in the interosseous muscles by stimulation of the tibial nerve were recorded, and linear regression analyses of the shortest latency versus the length of the tibial nerve and the limb length were performed. F-wave persistence was calculated by dividing the number of recorded F-waves by the number of stimuli. RESULTS: The correlation coefficient between F-wave latency and nerve length was 0.92, and that between F-wave latency and limb length was 0.58. Mean +/- SD F-wave conduction velocity of the tibial nerve was calculated to be 97.1 +/- 5.0 m/s. Linear regression analysis yielded the regression equation as follows: F-wave latency (milliseconds) = 2.60 + (0.02 x nerve length [mm]). Mean F-wave persistence and amplitude were 98.7 +/- 2.3% and 1.01 +/- 0.62 mV, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that nerve length should be used for nerve conduction studies of F-waves in felids. The regression equation for F-wave latency, conduction velocity, persistence, and amplitude may contribute to the diagnosis of nervous system diseases or injury in cats, such as trauma to the spinal cord or diabetic neuropathy.     

The normal response to repetitive motor nerve stimulation in dogs

The responses of certain muscles to stimulation at different frequencies has been studied in normal dogs. Repetitive stimulation at 10 and 20 Hz resulted in a smooth, progressive decremental response when the compound muscle action potential (CMAP) was recorded from the plantar, and to a lesser extent the palmar, interosseous muscles. In contrast, there was a slight incremental response when the CMAP was recorded from the cranial tibial muscle. Studies using a competitive neuromuscular blocking agent have suggested that the plantar interosseous muscles have a greater proportion of low efficacy synapses in comparison with the other muscles studied. The cranial tibial muscle may therefore be more suitable for assessing neuromuscular transmission than the distal limb muscles.     

Reference values for the bone marrow aspirates in adult dogs

Reference ranges for each cell type and six different ratios (M : E ratio = quotient of number of myeloid cells/erythroid precursors; different maturation ratios) were calculated for bone marrow aspirates of adult dogs. These values were based on 2.5 and 97.5% percentiles of differentials of 1000 cells in bone marrow aspirates of 92 healthy 1-8-year-old dogs. The results of intact male and female dogs were compared. No distinct sex-related differences were found (P > 0.05). A wide physiological range was observed in almost all bone marrow cells resulting in broad reference ranges for the ratios. The clinically relevant M : E ratio varied between 0.45 and 2.87. The accurate cytological examination of bone marrow based on the reference ranges presented in this study requires preparation of high-quality bone marrow films with minimal blood contamination.     

Hematological and clinical biochemical reference values for adult goats and sheep

Sheep and goat husbandry has always played an important role in swiss agriculture, but in recent years these animals are increasingly appreciated as hobby pets. This opens new diagnostic and therapeutic perspectives for veterinary surgeons, notably in the determination of hematological and clinical biochemical parameters. For the current methods used there are no reference range values available for adult sheep and goats kept under swiss conditions. Therefore, the present study was designed to determine haematological and clinical biochemical parameters in 102 goats and 102 sheep from swiss flocks. Significant differences were found between the two species, especially regarding erythrocyte count, mean erythrocyte volume, hemoglobin content as well as leukocyte count. It is therefore of utmost importance to discriminate between sheep and goats when interpreting laboratory tween findings.     

Maturation of spinal-evoked potentials to tibial and ulnar nerve stimulation in clinically normal dogs

Spinal-evoked potentials were recorded from 2 litters of clinically normal mixed-breed dogs between 35 and 300 days of age. Summated responses to tibial nerve stimulation were recorded from percutaneous needle electrodes placed at L7-S1, L4-5, T13-L1, C7-T1, and the cisterna cerebellomedullaris. The ulnar nerve was stimulated with recordings at C7-T1 and the cisterna cerebellomedullaris. Amplitudes did not change significantly with age, but were significantly (P less than 0.05) different between various recording sites. On day 35, segmental and overall (L7-cisterna cerebellomedullaris) conduction velocities were less than half of the adult values. Spinal cord conduction velocities increased with age, reaching adult values at approximately 9 months of age. It was determined that quadratic equations best predicted the conduction velocities during maturation.     

The effects of medetomidine on radial nerve blockade with mepivacaine in dogs

OBJECTIVE: To compare the sensory and motor effects of adding medetomidine to mepivicaine, administered either perineurally or systemically, for radial nerve block in dogs. STUDY DESIGN: Prospective randomized cross-over study. ANIMALS: Six healthy Beagles, aged 18.7 +/- 6.3 months and weighing 10.4 +/- 1.3 kg. METHODS: Dogs were anesthetized briefly with sevoflurane on three separate occasions and received each treatment administered in random order: mepivacaine 5 mg kg(-1) perineurally around the radial nerve with saline 0.01 mL kg(-1) intramuscularly (CONTROL); mepivacaine 5 mg kg(-1) and medetomidine 0.01 mg kg(-1) combined, perineurally with saline 0.01 mL kg(-1) intramuscularly (MEDPN); mepivacaine 5 mg kg(-1) perineurally around the radial nerve with medetomidine 0.01 mg kg(-1) intramuscularly (MEDIM). All nerve blocks were performed with the aid of a nerve locator. Motor effects were evaluated based on the ability to bear weight. Sensory effects were evaluated by the response to a graded-electrical stimulus. These were evaluated at 5-minute intervals for the first hour, and at 10-minute intervals thereafter. Mean intervals were calculated as follows: time to motor block onset, duration of motor block, time to peak sensory block, duration of peak sensory block (i.e. period of no response to maximal stimulus intensity), and duration of residual sensory block (i.e. time to return to baseline sensory function). Treatment means were compared using a one-way analysis of variance for repeated measures and, where significant differences were noted, a Student-Newman-Keuls test was applied; p < 0.05 was considered significant. RESULTS: Medetomidine, administered either systemically or perineurally, significantly prolonged duration of peak motor block, peak sensory block, and residual sensory block compared with CONTROL. CONCLUSION: Medetomidine prolonged sensory and motor blockade after radial nerve block with mepivacaine in dogs. CLINICAL RELEVANCE: Medetomidine may prove to be a useful adjunct to peripheral nerve blockade with local anesthetics.     

Development and verification of saphenous, tibial and common peroneal nerve block techniques for analgesia below the thigh in the nonchondrodystrophoid dog

OBJECTIVE: To document simple and reliable local, infiltrating nerve blocks for the saphenous, tibial and common peroneal nerves in the dog. STUDY DESIGN: Laboratory technique development; in vivo blind, controlled, prospective study. ANIMALS: Twenty canine cadavers and 18 clinically normal, client-owned dogs. METHODS: A peripheral nerve blockade technique of the tibial, common peroneal, and saphenous nerves was perfected through anatomic dissection. Injections were planned in the caudal thigh for the tibial and common peroneal nerves, and in the medial thigh for the saphenous nerve. Cadaver limbs were injected with methylene blue dye and subsequently dissected to confirm successful dye placement. Clinically normal dogs undergoing general anesthesia for unrelated, elective procedures were randomly assigned to treatment (bupivacaine; n = 8) or control (saline; n = 8) nerve blocks of the nerves under study. Upon recovery from general anesthesia, skin sensation in selected dermatomes was evaluated for 24 hours. RESULTS: Cadaver tibial, common peroneal, and saphenous perineural infiltrations were successful in nonchondrodystrophoid dogs (100, 100, and 97%, respectively.) Intraneural injection was rare (1%; 1/105; tibial nerve) in cadaver dogs. In the treatment group of normal dogs, duration of loss of cutaneous sensation in some dermatomes (saphenous, superficial and deep peroneal nerve) was significantly different than control dogs; the range of desensitization occurred for 1-20 hours. No clinical morbidity was detected. CONCLUSIONS: This technique for local blockade of the tibial, common peroneal, and saphenous nerves just proximal to the stifle is easy to perform, requires minimal supplies and results in significant desensitization of the associated dermatomes in clinically normal, nonchondrodystrophoid dogs. CLINICAL RELEVANCE: This technique may be an effective tool for post-operative analgesia to the femoro-tibial joint and distal pelvic limb. Other applications, using sustained-release drugs or methods, may include anesthesia/analgesia in high-risk patients or as a treatment for chronic pelvic limb pain or self-mutilation.     

Peripheral nerve block versus systemic analgesia in dogs undergoing tibial plateau levelling osteotomy: Analgesic efficacy and pharmacoeconomics comparison

ObjectiveTo compare the perioperative effects and pharmacoeconomics of peripheral nerve blocks (PNBs) versus fentanyl target-controlled infusion (fTCI) in dogs undergoing tibial plateau levelling osteotomy (TPLO).Study designRandomized clinical study.AnimalsA total of 39 dogs undergoing unilateral TPLO.MethodsAfter acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane. Dogs were allocated to group fTCI [target plasma concentration (TPC) 1 ng mL^–1] or group PNB (nerve stimulator-guided femoral-sciatic block using 0.2 and 0.1 mL kg^–1 of levobupivacaine 0.5%, respectively). If nociceptive response occurred, isoflurane was increased by 0.1%, and TPC was increased by 0.5 ng mL^–1 in group fTCI; a fentanyl bolus (1 μg kg^–1) was administered in group PNB. During the first 24 postoperative hours, methadone (0.2 mg kg^–1) was administered intramuscularly according to the Short Form Glasgow Composite Pain Scale, or if pain was equal to 5/24 or 4/20 for two consecutive assessments, or if the dog was non-weight bearing. The area under the curve (AUC) of pain scores, cumulative postoperative methadone requirement, food intake and pharmacoeconomic implications were calculated.ResultsIncidence of bradycardia (p = 0.025), nociceptive response to surgery (p = 0.041) and AUC of pain scores (p < 0.0001) were greater in group fTCI. Postoperatively, 16/19 (84.2%) and eight/20 (40%) dogs in groups fTCI and PNB, respectively, were given at least one dose of methadone (p = 0.0079). Food intake was greater in group PNB (p = 0.049). Although total cost was not different (p = 0.083), PNB was more cost-effective in dogs weighing >15 kg.Conclusions and clinical relevanceCompared with group fTCI, incidence of bradycardia, nociceptive response to surgery, postoperative pain scores, cumulative methadone requirement were lower, and food intake was greater in group PNB, with an economic advantage in dogs weighing >15 kg.     

Plasma salicylate concentrations in immature dogs following aspirin administration: comparison with adult dogs

Aspirin disposition in immature and adult dogs, assessed by plasma salicylate concentrations following single doses of aspirin given orally (p.o.) and intravenously (i.v.), was compared. Using a cross-over design, four immature (12–16-weeks-old) and eight adult (1– 2-years-old) dogs were given a single dose of aspirin at 17.5 mg/kg body weight i.v. and a single dose of buffered aspirin at 35 mg/kg body weight p.o. Blood was collected from the jugular vein for 24 h following each dose. A fluorescence polarization immunoassay was used for determination of salicylate in plasma. Significant differences in aspirin disposition were identified between the two groups. Immature dogs had significantly shorter salicylate half-life, lower mean residence time, and more rapid salicylate clearance than adult dogs. The difference in volume of distribution between the two groups was not significantly different. Immature dogs had lower mean (± SD) peak plasma salicylate concentrations (64.5 ± 2.38 mg/L) than adult dogs (95.9 ± 12.2 mg/L) following a single oral dose of buffered aspirin at 35 mg/kg body weight. Predicted plasma salicylate concentration-time curves were constructed for various aspirin dosage regimens. This analysis showed that the previously recommended buffered aspirin dose for adult dogs of 25 mg/kg body weight p.o. every 8 h would be ineffective in maintaining plasma salicylate concentrations > 50 mg/L in immature dogs.     

Effects of amitraz on nerve conduction and neuromuscular transmission in anaesthetised dogs

Ataxia is an occasional side effect of amitraz when used as a wash to treat dogs with demodectic mange. In the present study, successive doses of 0.5, 2, 5 and 10 mg kg-1 amitraz were given intravenously at intervals of nine minutes to thiopentone/methoxyflurane/oxygen anaesthetised dogs. The amplitude of the evoked muscle action potential to electrical stimulation of the right ulnar nerve and the muscle refractory period were unchanged by increasing doses of amitraz but there was a progressive and significant decrease in nerve conduction velocity. The minimum recorded nerve conduction velocity (50.7 +/- 1.5 m s-1) was still within an adequate range. From these results it appears that the ataxia following amitraz is unlikely to be attributable to peripheral mechanisms. The concurrent amitraz-induced rise in mean arterial pressure and bradycardia was consistent with previous findings in which alpha 2-adrenoceptors were shown to be the major mediators.     

Femoral and sciatic nerve blockade of the pelvic limb with and without obturator nerve block for tibial plateau levelling osteotomy surgery in dogs

ObjectiveTo determine the effect of blocking the obturator nerve in addition to performing femoral nerve and sciatic nerve blocks on intraoperative nociception in dogs undergoing unilateral tibial plateau levelling osteotomy (TPLO) surgery.Study designProspective, blinded, randomized, placebo-controlled, clinical comparison.AnimalsA total of 88 client-owned dogs undergoing unilateral TPLO surgery (100 procedures).MethodsDogs were randomly assigned to either group FSO (femoral, sciatic and obturator nerve blocks) [n = 50; ropivacaine 0.75% (0.75 mg kg^–1)] or group FSP (femoral, sciatic and placebo) [n = 50; ropivacaine 0.75% (0.75 mg kg^–1) femoral and sciatic nerve blocks plus saline solution 0.9% (0.1 mL kg^–1) as a placebo injection around the obturator nerve]. The anaesthetic protocol was standardized. Data collection included intraoperative cardiopulmonary variables and opioid consumption. Rescue analgesia consisted of an intravenous bolus of fentanyl (2 μg kg^–1) and was administered when a change in cardiopulmonary variables (20% increase in mean arterial pressure or heart rate) was attributed to a sympathetic stimulus. Data were analysed using generalized linear mixed models, cross tables and multivariable binary logistic regression. Results were expressed as adjusted odds ratios with 95% confidence intervals and Wald p values (α = 0.05).ResultsThere were no clinically relevant differences between groups in intraoperative cardiopulmonary variables and need for rescue analgesia. The requirement for rescue analgesia was significantly higher in dogs with a body weight >34 kg.Conclusions and clinical relevanceAnaesthesia of the obturator nerve in addition to the femoral and sciatic nerves was not associated with clinically significant differences in cardiopulmonary variables or a reduced need for rescue analgesia. Therefore, the clinical benefit of an additional obturator nerve block for intraoperative antinociception in dogs undergoing unilateral TPLO surgery using the described anaesthetic regimen is low.     

Retrospective comparison between minimally invasive plate osteosynthesis and open plating for tibial fractures in dogs

Objectives: To compare fracture healing in diaphyseal tibial fractures stabilized using either minimally invasive plate osteosynthesis (MIPO) or open reduction and internal fixation (ORIF). Methods: Dogs in each group were matched for type of fracture, age and body weight. Stage of healing was measured blindly every four weeks postoperatively until complete healing. Outcome variables including fracture length, plate length, plate bridging ratio, plate working length, healing grading, and fracture reduction were compared between groups using the Mann-Whitney test. Significant difference was set at p <0.05. Results: Based on the definition of clinical union, at 30 days five out of eight dogs managed with MIPO had healed, while two of the eight of dogs managed with ORIF had healed. We did not find any significant differences in the other outcome measures. No complications were reported in the MIPO group whereas one major complication was reported in the ORIF group. Clinical significance: All dogs treated by MIPO healed rapidly without any complications, nevertheless the difference in radiographic healing between the two groups was not significant.     

Use of quantitative two-dimensional color tissue Doppler imaging for assessment of left ventricular radial and longitudinal myocardial velocities in dogs

OBJECTIVE: To determine left ventricular free wall (LVFW) radial and longitudinal myocardial contraction velocities in healthy dogs via quantitative 2-dimensional color tissue Doppler imaging (TDI). ANIMALS: 100 dogs. PROCEDURE: TDI was used by a single trained observer to measure radial and longitudinal myocardial movement in the LVFW. Radial myocardial velocities were recorded in segments in the endocardial and epicardial layers of the LVFW, and longitudinal velocities were recorded in segments at 3 levels (basal, middle, apical) of the LVFW. RESULTS: LVFW velocities were higher in the endocardial layers than in the epicardial layers. Left ventricular free wall velocities were higher in the basal segments than in the middle and apical segments. Radial myocardial velocity gradients, defined as the difference between endocardial and epicardial velocities, were (mean +/- SD) 2.5 +/- 0.8 cm/s, 3.8 +/- 1.5 cm/s, and 2.3 +/- 0.9 cm/s in systole, early diastole, and late diastole, respectively. Longitudinal myocardial velocity gradients, defined as the difference between basal and apical velocities, were 5.9 +/- 2.2 cm/s, 6.9 +/- 2.5 cm/s, and 4.9 +/- 1.7 cm/s in systole, early diastole, and late diastole, respectively. A breed effect was detected for several systolic and diastolic TDI variables. In all segments, systolic velocities were independent of fractional shortening. CONCLUSIONS AND CLINICAL RELEVANCE: LVFW myocardial velocities decreased from the endocardium to the epicardium and from base to apex, thus revealing intramyocardial radial and longitudinal velocity gradients. These indices could enhance conventional echocardiographic analysis of left ventricular function in dogs. Breed-specific reference intervals should be defined.     

Comparison of P-wave dispersion in healthy dogs,dogs with chronic valvular disease and dogs with disturbances of supraventricular conduction

Background

P-wave dispersion (P_d) is a new ECG index used in human cardiology and veterinary medicine. It is defined as the difference between the maximum and the minimum P-wave duration recorded from multiple different ECG leads. So far no studies were performed assessing the importance of P-wave dispersion in dogs.

Methods

The current study was aimed at determining proper value of P_d in healthy dogs (group I), dogs with chronic valvular disease (group II) and dogs with disturbances of supraventricular conduction (group III). The tests were carried out in 53 healthy dogs, 23 dogs with chronic valvular disease and 12 dogs with disturbances of supraventricular conduction of various breeds, sexes and body weight from 1,5 to 80 kg, aged between 0,5 and 17 years, submitted to the ECG examination. ECG was acquired in dogs in a standing position with BTL SD-8 electrocardiographic device and analyzed once the recording was enlarged. P-wave duration was calculated in 9 ECG leads (I, II, III, aVR, aVL, aVF, V1, V2, V4) from 5 cardiac cycles.

Results

The proper P-wave dispersion in healthy dogs was determined at up to 24 ms. P-wave dispersion was statistically significant increased (p < 0.01) in dogs with chronic valvular disease and dogs with disturbances of supraventricular conduction. In dogs with the atrial enlargement the P-wave dispersion is also higher than in healthy dogs, although no significant correlation between the size of left atria and Pd was noticed (p = 0.1, r = 0,17).

Conclusions

The P-wave dispersion is a constant index in healthy dogs, that is why it can be used for evaluating P wave change in dogs with chronic valvular disease and in dogs with disturbances of supraventricular conduction.     

Biomechanical comparison of cortical radial graft versus ulnar transposition graft limb-sparing techniques for the distal radial site in dogs

OBJECTIVE: To compare the biomechanical properties of radial graft (RG) versus ulnar transposition graft (UTG) limb-sparing techniques in the dog. STUDY DESIGN: Cadaveric study. ANIMALS: Six pairs of normal canine thoracic limbs. METHODS: In each pair of limbs, 1 limb was subjected to the RG technique and the other to the UTG technique. Limbs were tested in axial loading until failure. Modes of failure and biomechanical properties were compared between the 2 groups. Percent coverage of the metacarpal bone by the plate was retrospectively compared between the limbs that failed by fracture of the metacarpal bones and those that did not. RESULTS: RG limbs had significantly greater stiffness, yield load, maximum load, maximum energy, and post-yield energy. All UTG limbs failed by cranial bending of the plate. Half of the RG limbs failed by caudal bending of the plate and half by fracture of the third metacarpal bone at the distal end of the plate. Limbs with <80% plate coverage of the metacarpal bone were significantly more likely to fail by metacarpal fracture. CONCLUSIONS: The RG technique was biomechanically superior to the UTG technique under the conditions studied. At least 80% plate coverage of the metacarpal bone should be achieved. CLINICAL RELEVANCE: Exercise restriction and coaptation bandages should be considered for patients undergoing the UTG technique to minimize potential biomechanical complications.     

Controlled, clinical trial assessing saphenous, tibial and common peroneal nerve blocks for the control of perioperative pain following femoro-tibial joint surgery in the nonchondrodystrophoid dog

OBJECTIVE: To determine whether bupivacaine peripheral nerve block of the saphenous, tibial and common peroneal nerves proximal to the femoro-tibial joint reduces peri-operative pain following extracapsular surgical stabilization of cranial cruciate ligament rupture in the nonchondrodystrophoid dog. ANIMALS: Forty-one dogs with naturally acquired femoro-tibial joint instability. Study design Randomized, controlled, clinical trial. METHODS: Dogs diagnosed with suspected cranial cruciate ligament injury based on physical and radiographic evidence were randomly assigned to treatment (bupivacaine) or control (saline) nerve blocks before femoro-tibial joint surgery. Pain scores, skin sensation, pain threshold to incisional pressure, time to first systemic 'rescue' opioid analgesic and total analgesic dose were evaluated for 24 hours. p < 0.05 was considered significant. RESULTS: Treatment dogs had a significantly longer period of cutaneous desensitization than control dogs. There were no significant differences between treatment and control groups for pain score, pain threshold to incisional pressure, or time to first-rescue analgesic. The treatment group received significantly more supplemental analgesics than the control group. CONCLUSIONS: These peripheral nerve blocks were easy to perform and resulted in significant desensitization of the associated nerve autonomous zones, but did not improve post-operative analgesia. CLINICAL RELEVANCE: Clinical benefit was not detected when using this technique for peri-operative pain management following extracapsular cranial cruciate ligament surgical stabilization.