Dog Hindlimb Research Articles

3D Slicer open-source software plug-in for vector-based angle calculation of canine hind limb alignment in computed tomographic images.

Severe and complex angular limb deformities in dogs require accurate morphological assessment using diagnostic imaging to achieve successful orthopedic surgery. Computed tomography (CT) is commonly used to overcome projection errors in two-dimensional angular measurements of dog hindlimb alignment. Three-dimensional volume rendering (VR) techniques permit virtual positioning and variable projection, but the final CT-image that defines the projection plane for angular measurements remains two-dimensional. We wanted to develop a true three-dimensional open-source technique to measure the alignments of the hind limbs of dogs in CT scanners. We developed an open-source 3D Slicer plug-in, to perform angular measurements using vector calculations in three-dimensional space. In 113 CT-scans of canine pelvic limbs, femoral torsion, femoral varus, femorotibial rotation, tibial torsion, tibial varus and tibiotalar rotation angles were calculated and compared to an already validated technique using VoXim®. Reference points were identified and measurements were possible in the 113 acquisitions. The greatest difference between the two techniques was 1.4° at only one tibial torsion angle. Mean values for all Bland-Altman plots did not show significant differences and were less than 0.07° for all comparisons. Based on these results we considered angular measurements of canine hind limb alignment in CT scans using the 3D Slicer extension program sufficiently accurate for clinical orthopedic and surgical purposes in veterinary medicine. With our open-source 3D Slicer extension software, we provide a free accessible tool for veterinary orthopedic surgeons and thus we hope to improve angular measurements in CT-scans of canine hind limb deformities through true three-dimensionality.

Muscle function assessment of the hindlimbs in healthy dogs using acoustic myography

IntroductionImpaired muscle function is a frequent consequence of musculoskeletal disorders in dogs. Musculoskeletal disorders, especially stifle joint diseases, are common in dogs and assessment of muscle function in dogs is clinically relevant. Acoustic myography (AMG) is a non-invasive method to assess muscle activity. Quantifying muscle function in normal dogs could help identify clinically relevant changes in dogs with orthopaedic disease and allow targeted interventions to improve recovery in these. The objectives of the study were to characterize hindlimb muscle function in healthy dogs using AMG and to investigate the repeatability and reproducibility of AMG in dogs. MethodsHealthy dogs (15–40 kg) without musculoskeletal disorders were recruited and screened for eligibility to participate in the study. The muscle activity in four hindlimb muscles related to the stifle was assessed using AMG. The degree of symmetry between the hindlimbs in these dogs was investigated and the reliability of AMG was evaluated. Results and conclusionsThe study population comprised 21 dogs. Reference intervals and symmetry indices for AMG scores of the hindlimb muscles were identified, with highest variability for the E-scores. For all AMG-scores, same-day variation was lower than between days variation, and both were lowest for S- and T-scores. Further investigation is needed to establish if AMG can enable discrimination between dogs with altered muscle function and healthy dogs.

Evaluation of the accuracy and intra- and interobserver reliability of three manual laxity tests for canine cranial cruciate ligament rupture-An ex vivo kinetic and kinematic study.

To investigate the accuracy and intra- and interobserver reliability of the cranial drawer test (CD), tibial compression test (TCT), and the new tibial pivot compression test (TPCT) in an experimental setting resembling acute cranial cruciate ligament rupture (CCLR) and to elucidate the ability to subjectively estimate cranial tibial translation (CTT) during testing. Experimental ex vivo study. Ten cadaveric hindlimbs of large dogs. Kinetic and 3D-kinematic data was collected while three observers performed the tests on each specimen with intact (INTACT) and transected cranial cruciate ligament (CCLD) and compared using three-way repeated-measures ANOVA. Subjectively estimated CTT (SCTT), obtained during a separate round of testing, was compared to kinematic data by Pearson correlation. CTT was significantly higher for CCLD than for INTACT for all tests, resulting in 100% sensitivity and specificity. TPCT induced the highest CTT and internal rotation. Intra- and interobserver agreement of translation was excellent. For rotation and kinetics, agreement was more variable. SCTT strongly correlated with the objectively measured values. The CD, TCT and the new TPCT were all accurate and reliable. The high translations and rotations during TPCT are promising, encouraging further development of this test. SCTT was reliable in our experimental setting. Veterinary manual laxity tests are accurate and reliable in acute CCLR. The TPCT might have potential for the assessment of subtle and rotational canine stifle instabilities. The high reliability of SCTT implies that grading schemes for stifle laxity, similar to human medicine, could be developed.

Comparative kinetic and kinematic evaluation of TPLO and TPLO combined with extra-articular lateral augmentation: A biomechanical study.

To investigate stifle kinematics and kinetics following TPLO and TPLO combined with an extra-articular lateral augmentation (TPLO-IB) during the tibial compression test (TCT) and the tibial pivot compression test (TPT), applied with an external (eTPT) and an internal moment (iTPT). Experimental ex vivo study. Ten cadaveric hindlimbs of dogs weighing 23-40 kg. 3D-kinematic and kinetic data were collected while performing TCT, eTPT, and iTPT and compared under the conditions (1) normal, (2) CCL deficient, (3) TPLO, and (4) TPLO-IB. Two-way repeated-measures ANOVA was used to examine the effect of test and treatment on kinetic and kinematic data. Mean ± SD preoperative TPA was 24.7° ± 1.7°, postoperative TPA was 5.9° ± 0.7°. During TCT, there was no difference in cranial tibial translation between the intact stifle and after TPLO (p = .17). In contrast, cranial tibial translation was six times larger in TPLO compared to intact when performing eTPT and iTPT (p < .001). Cranial tibial translation with TCT, eTPT and iTPT was not different between intact stifle and TPLO-IB. Intraclass correlation coefficient for eTPT and iTPT after TPLO and TPLO-IB was excellent being 0.93 (0.70-0.99) and 0.91 (0.73-0.99), respectively. Whereas TCT is negative after TPLO, instability persists when a rotational moment is combined using eTPT and iTPT. TPLO-IB neutralizes craniocaudal and rotational instability when performing TCT, eTPT, and iTPT.

PhysiCan - a device for automatic CPM exercises implementation over canines: Design and analysis

Continuous Passive Motion (CPM) devices have been used to assist physicians conducting human rehabilitation; however, similar machines specific for canine rehabilitation have not been found in the reviewed literature. This research performed a physical analysis of the hind limb of dogs to design a device for implementing automated CPM exercises. The device proved to comply with the guidelines to perform CPM exercises, allowing a proper setting of parameters to generate rehabilitation routines customized for different rehabilitation requirements. Also, an electromyography acquisition module was incorporated into the system, with surface electrodes to visualize and provide feedback to the user for muscle activation. Limitations were encountered with a range of motion of 80° and an error of approximately 2% for angular position accuracy.

Ratio of venous-to-arterial PCO2 to arteriovenous oxygen content difference during regional ischemic or hypoxic hypoxia

The purpose of the study was to evaluate the behavior of the venous-to-arterial CO2 tension difference (ΔPCO2) over the arterial-to-venous oxygen content difference (ΔO2) ratio (ΔPCO2/ΔO2) and the difference between venous-to-arterial CO2 content calculated with the Douglas’ equation (ΔCCO2D) over ΔO2 ratio (ΔCCO2D/ΔO2) and their abilities to reflect the occurrence of anaerobic metabolism in two experimental models of tissue hypoxia: ischemic hypoxia (IH) and hypoxic hypoxia (HH). We also aimed to assess the influence of metabolic acidosis and Haldane effects on the PCO2/CO2 content relationship. In a vascularly isolated, innervated dog hindlimb perfused with a pump-membrane oxygenator system, the oxygen delivery (DO2) was lowered in a stepwise manner to decrease it beyond critical DO2 (DO2crit) by lowering either arterial PO2 (HH-model) or flow (IH-model). Twelve anesthetized and mechanically ventilated dogs were studied, 6 in each model. Limb DO2, oxygen consumption ({dot{text{V}}text{O}}_{2}), ΔPCO2/ΔO2, and ΔCCO2D/ΔO2 were obtained every 15 min. Beyond DO2crit, {dot{text{V}}text{O}}_{2} decreased, indicating dysoxia. ΔPCO2/ΔO2, and ΔCCO2D/ΔO2 increased significantly only after reaching DO2crit in both models. At DO2crit, ΔPCO2/ΔO2 was significantly higher in the HH-model than in the IH-model (1.82 ± 0.09 vs. 1.39 ± 0.06, p = 0.002). At DO2crit, ΔCCO2D/ΔO2 was not significantly different between the two groups (0.87 ± 0.05 for IH vs. 1.01 ± 0.06 for HH, p = 0.09). Below DO2crit, we observed a discrepancy between the behavior of the two indices. In both models, ΔPCO2/ΔO2 continued to increase significantly (higher in the HH-model), whereas ΔCCO2D/ΔO2 tended to decrease to become not significantly different from its baseline in the IH-model. Metabolic acidosis significantly influenced the PCO2/CO2 content relationship, but not the Haldane effect. ΔPCO2/ΔO2 was able to depict the occurrence of anaerobic metabolism in both tissue hypoxia models. However, at very low DO2 values, ΔPCO2/ΔO2 did not only reflect the ongoing anaerobic metabolism; it was confounded by the effects of metabolic acidosis on the CO2–hemoglobin dissociation curve, and then it should be interpreted with caution.

Anatomical Study of Some Selected Bones of the Hind Limb of Local Domestic Dog ( Canis lupus familiaris )

This study was aimed at investigating the age related changes in the morphometry and biometry of some selected bones of the hind limb of Nigerian local dog ( canis lupus familiaris ). In this study a total of fifteen dogs were used as sample and were grouped into five age categories (group A-E). The dogs were aged by estimation using dentition eruption and wearing. The segment of the hind limb was identified and separated from the rest from other parts. The gross study of the hind limb revealed that the hind limb was composed of: ossa coxarum, femur, patella, tibia, fibula, tarsal and metatarsal bones. The biometric study revealed that the weight, length, width and circumference were found to be increasing with advancement in age. The result revealed that mean weight, length and circumference of various segments of the ossa coxarum, femur and the tibia tends to increase with age across the group that is from group A to group E. However, there is variation in the length of the fibula, width of the obturator foramen and length of the obturator foramen. Base on the above results, it was concluded that base line data was established with the aim of enhancing learning.

Effects of epidural bupivacaine, bupivacaine-butorphanol and bupivacaine-morphine on postoperative analgesia for hind limb and pelvic orthopedic operations in dogs

The aim of this study was to compare the postoperative analgesic effects of epidural bupivacaine, bupivacaine-butorphanol and bupivacaine-morphine in hind limb and pelvic orthopedic operations in dogs. Three groups each containing 10 dogs were formed. Through the lumbosacral space, group B was administered bupivacaine, 1 mg kg-1; group BB was administered bupivacaine, 1 mg kg-1 and butorphanol, 0.25 mg kg-1; and group BM was administered bupivacaine, 1 mg kg-1 and morphine, 0.1 mg kg-1. Anaesthesia was induced with diazepam (0.2 mg kg-1) and propofol (5 mg kg-1) and maintenance with isoflurane in oxygen. Pain assessment was performed with the University of Melbourne Pain Scale (UMPS) by a blinded observer. Plasma cortisol levels were measured preoperatively and postoperatively. Postoperative pain scores were significantly lower at 2 hours in the group BM, and at 8 and 12 hours in the groups BB and BM compared to the group B (P=0.007). Group BM had a lower plasma cortisol level than the group B at 2 hours (P=0.002). Bupivacaine-butorphanol and bupivacaine-morphine use were shown to provide longer analgesia in the postoperative period; and the epidural administration of bupivacaine-butorphanol and bupivacaine-morphine was considered to be potentially useful in clinical practice.

Alterations in the ground reaction force of dogs during trot after immobilization of the stifle joint: An experimental study.

This study aimed to evaluate changes in the vertical and fore-aft force generation of the hindlimbs in dogs with stifle orthoses. Custom-made orthoses were used on the right stifle joint. Force plate and marker data from four beagle dogs in trials without orthoses, with fixed orthoses, and with unfixed orthoses were collected. The vertical ground reaction force of the right side was increased with fixed orthoses and decreased with unfixed orthoses compared to that of gait without orthoses. When compared to that of gait without orthoses, the fore-aft ground reaction force changed with fixed orthoses but not with unfixed orthoses. It is suggested that the level of constraint of the orthosis affected the ground reaction force pattern.

Short-term outcomes and complications of 65 cases of porous TTA with flange: a prospective clinical study in dogs

BackgroundCranial cruciate ligament rupture (CrCLR) is the most common orthopaedic cause of lameness in the hind limb in dogs. Many surgical treatments have been described, but tibial tuberosity advancement (TTA) is one of the most commonly used today. Since it was first described, TTA has evolved to reduce major complications and to arrest the progression of osteoarthrosis. The aim of this study was to assess a surgical technique called Porous TTA with flange prospectively. This study was performed in 61 dogs that underwent 65 Porous TTA with flange procedures, to validate it as an alternative CrCLR treatment. Complications and clinical outcomes (pain, lameness, weight bearing, flexion, extension, crepitation and atrophy) were reported over 3 months, i.e. at 3, 6 and 12 weeks postoperatively.ResultsThe results showed a positive clinical outcome, a minor complication rate of 47.69% at the first review 3 weeks postoperatively, 10.77% at the second one (6 weeks after the surgery) and 4% at the third one (at 12 weeks). Major complications were observed only at the last review, with one case that had an infection requiring implant removal; this represented 1.5% of cases. Variables evaluated for a relationship with complication scores and improvement were body condition score, sex, age, breed, body weight, breed size, side of the affected limb, traumatic anamnesis and time of lameness before surgery. No relationship was detected.ConclusionsClinical outcomes and complications show that Porous TTA with flange is an efficient alternative for surgical treatment of CrCLR in dogs.

Single-day and multiday repeatability of stance analysis results for dogs with hind limb lameness.

To assess single-day and multiday repeatability of weight distribution (stance) data obtained with a commercial analyzer for dogs with naturally occurring hind limb lameness. 46 dogs (15 and 31 for single-day and multiday trials, respectively). For single-day trials, 5 to 10 measurements/trial were collected to determine body weight (BW), weight distribution on each limb, and forelimb and hind limb symmetry indices (SIs). The dog was removed from the room and returned immediately; 5 trials were performed. For multiday trials, measurements were performed in the same manner on 2 sequential days. Data were compared among trials (single-day measurements) and between days (multiday measurements). Repeatability (correlation coefficients and Lin concordance correlation coefficients [LCCCs]) and variability (coefficients of variation [CVs]) were assessed. In single-day trials, BW (r = 0.999), weight distribution on the lame hind limb (r = 0.915) and contralateral hind limb (r = 0.948), and hind limb SI (r = 0.964) were each significantly correlated among trials. In multiday trials, BW results were similar; weight distribution on the lame hind limb and contralateral hind limb and hind limb SI were each less closely but still significantly correlated between days. The LCCCs were highest for BW, weight distribution on the contralateral hind limb, and hind limb SI in single-day trials and for BW and weight bearing on the contralateral and lame hind limbs in multiday trials. The CVs were lowest for BW and highest for forelimb SI in both trial types. The analyzer used allowed repeatable measurement of BW and weight distribution on the hind limbs of dogs with hind limb lameness. Measurement of forelimb stance variables was not repeatable in this group of dogs.

Assessment of the Thermal Paw Print Symmetry of the Hind Legs in Healthy Dogs

Abstract Our bibliographic insights have shown that although thermographic imaging in small animals has been poorly studied, the empirical use of thermographic images in dogs suggests that thermographic imaging could be a useful method in assessing walking anomalies. The study aims to identify existing thermal asymmetries between the thermal paw prints of the hind limbs in healthy dogs (right versus left). For thermal investigations, the Flir E50 thermal camera with a resolution of 240×180, thermal sensitivity of 0.05ºC, 45º×34ºA visual field and unbalanced microbolometer was used. Acclimatization of the animals in the space for examination was 30 minutes (at a room temperature of 20-23°C). The resulting images were recorded, processed and analyzed with the Flir tools 2017 software. The average, maximum and minimum temperature of each image was calculated using the program. The results obtained show that between the thermal paws marks of the posterior limbs in healthy dogs there is an average thermal asymmetry comprised between 0.2 and 1.4°C. Our study suggested that, under controlled conditions, thermographic paws prints could be used to diagnose locomotor abnormalities in dogs..

Clinical comparison of the effects of isoflurane or propofol anaesthesia on mean arterial blood pressure and ventilation in dogs undergoing orthopaedic surgery receiving epidural anaesthesia

The aim of this study was to compare the effects on mean arterial pressure (MAP) and ventilation of propofol total IV anaesthesia (TIVA) and isoflurane as anaesthetic maintenance in healthy dogs undergoing orthopaedic surgery, with epidural anaesthesia. Dogs were premedicated IM with dexmedetomidine (4μg/kg) and methadone (0.3mg/kg), induced with IV propofol (0.65–5mg/kg) and randomly assigned to be maintained with isoflurane (group I) or propofol (group P). Isoflurane end-tidal concentration (EtISO) and propofol infusion rate were adjusted during the surgery to maintain a suitable anaesthetic depth. All dogs received bupivacaine (1mg/kg) and morphine (0.1mg/kg) in the lumbosacral epidural space (total volume 0.2mL/kg). MAP was recorded every 5min during the procedure. Statistical analysis was performed using parametric (Student’s t test) and nonparametric (Mann–Whitney U-test, chi-square) tests, as appropriate.Anaesthetic maintenance in groups I and P was accomplished by providing a mean EtISO of 1.12±0.15% and a mean propofol infusion rate of 15.0±4.7mg/kg/h, respectively. MAP was significantly higher in group P than in group I (92±17mmHg versus 78±10mmHg; P=0.021). Eleven dogs in group P and two dogs in group I reached an EtCO2>7.3kPa, requiring mechanical ventilation (P=0.001). In combination with epidural anaesthesia, propofol TIVA improved MAP and is a suitable alternative to isoflurane in orthopaedic surgery of the hind limb in healthy dogs. Nevertheless, since it was associated with increased respiratory depression, mechanical ventilation should be available.

Effect of Limb Position at the Time of Skin Marker Application on Sagittal Plane Kinematics of the Dog.

Objectives To evaluate the effect of limb position during initial skin marker application on sagittal plane kinematics of the hindlimb. Methods Six healthy dogs (20–30 kg) were evaluated. An established two-dimensional kinematic model of the pelvic limb was utilized to describe sagittal plane motion. Kinematic markers were applied separately for each dog while standing in three different positions: (1) the limb extended cranially, (2) a normal standing limb position and (3) the limb extended caudally. Following marker application at each of the three positions, dynamic gait was recorded at a walk (velocity, 0.9–1.2 m/s; acceleration, 0.5m/s 2 ). Five valid trials were used for comparison. Complete waveform analysis was performed with generalized indicator function analysis (GIFA). Maximum and minimum joint angles and joint range of motion were compared with a one-way repeated measures ANOVA with significance at p < 0.05. Results Significant differences were found between stifle waveforms. No differences were found between the hip or tarsus waveforms. Minimum and maximum joint angles were significantly different for the hip and stifle but not for the tarsus. No differences were found between ranges of motion for any joint evaluated. Clinical Significance Limb position at the time of skin marker application affects gait data and is an important consideration for kinematic analysis of the hindlimb in dogs.

A novel jig arm to measure tibial plateau angle during tibial plateau leveling osteotomy.

To determine the ability of a novel device attached to the proximal tibial plateau leveling osteotomy (TPLO) jig pin to accurately predict intraoperative change in tibial plateau angle (TPA). In vitro cadaveric study. Left hindlimbs of adult dogs (n = 9). A modified Slocum tibial plateau leveling (TPL) jig with the Rotational Osteotomy Measuring Arm (ROMA) was placed on the tibia and a radial TPLO osteotomy was performed. Based on preoperative radiographic TPA measurements, the proximal segment was rotated using the traditional method of marking points on the osteotomy a specified distance apart. After rotation, the predicted TPA was recorded based on the ROMA. Postoperative TPA was measured on radiographs. The ability of the ROMA to predict postoperative TPA was compared to that of the traditional method. The average final TPA achieved with the traditional method was 6.4° (range, 3.0-10.0°). The ROMA predicted a final TPA of 5.8° (range, 3.8-10.1°). No significant difference was found between the TPA predicted based on the traditional method and ROMA method. The ROMA may be an alternative to the traditional method of measuring proximal segment rotation during TPLO procedure. Performing a TPLO with the ROMA may accurately predict the postoperative TPA while eliminating the need for measuring chord length, making reference marks, or referencing TPA charts for various osteotomy blade sizes.

Ranking of physiotherapeutic evaluation methods as outcome measures of stifle functionality in dogs

BackgroundVarious physiotherapeutic evaluation methods are used to assess the functionality of dogs with stifle problems. Neither validity nor sensitivity of these methods has been investigated. This study aimed to determine the most valid and sensitive physiotherapeutic evaluation methods for assessing functional capacity in hind limbs of dogs with stifle problems and to serve as a basis for developing an indexed test for these dogs. A group of 43 dogs with unilateral surgically treated cranial cruciate ligament deficiency and osteoarthritic findings was used to test different physiotherapeutic evaluation methods. Twenty-one healthy dogs served as the control group and were used to determine normal variation in static weight bearing and range of motion.The protocol consisted of 14 different evaluation methods: visual evaluation of lameness, visual evaluation of diagonal movement, visual evaluation of functional active range of motion and difference in thrust of hind limbs via functional tests (sit-to-move and lie-to-move), movement in stairs, evaluation of hind limb muscle atrophy, manual evaluation of hind limb static weight bearing, quantitative measurement of static weight bearing of hind limbs with bathroom scales, and passive range of motion of hind limb stifle (flexion and extension) and tarsal (flexion and extension) joints using a universal goniometer. The results were compared with those from an orthopaedic examination, force plate analysis, radiographic evaluation, and a conclusive assessment. Congruity of the methods was assessed with a combination of three statistical approaches (Fisher’s exact test and two differently calculated proportions of agreeing observations), and the components were ranked from best to worst. Sensitivities of all of the physiotherapeutic evaluation methods against each standard were calculated.ResultsEvaluation of asymmetry in a sitting and lying position, assessment of muscle atrophy, manual and measured static weight bearing, and measurement of stifle passive range of motion were the most valid and sensitive physiotherapeutic evaluation methods.ConclusionsRanking of the various physiotherapeutic evaluation methods was accomplished. Several of these methods can be considered valid and sensitive when examining the functionality of dogs with stifle problems.

Hind limb kinematics during therapeutic exercises in dogs with osteoarthritis of the hip joints

To assess joint kinematics in dogs with osteoarthritis of the hip joints during walking up an incline or down a decline and over low obstacles and to compare findings with data for nonlame dogs. 10 dogs with osteoarthritis of the hip joints (mean ± SD age, 6.95 ± 3.17 years; mean body weight, 34.33 ± 13.58 kg) and 8 nonlame dogs (3.4 ± 2.0 years; 23.6 ± 4.6 kg). Reflective markers located on the limbs and high-speed cameras were used to record joint kinematics during walking up an incline or down a decline and over low obstacles. Maximal flexion, extension, and range of motion of the hip joints were calculated. Osteoarthritis of the hip joints reduced extension of both hip joints and flexion of the contralateral hind limb, compared with flexion of the lame hind limb, during walking down a decline. Walking up an incline resulted in decreased extension of the stifle joint in both hind limbs of osteoarthritic dogs; extension was significantly decreased for the lame hind limb. During walking over low obstacles, maximal flexion of the stifle joint was increased significantly for the contralateral hind limb. Maximal flexion was increased in both tarsal joints. Osteoarthritis of the hip joints led to complex changes in the gait of dogs, which involved more joints than the affected hip joint alone. Each exercise had specific effects on joint kinematics that must be considered when planning a rehabilitation program.

Welcome the carotid chemoreflex to the ‘neural control of the circulation during exercise’ club

Chemoreceptors in the brain (central chemoreceptors) and in the carotid sinus (peripheral chemoreceptors) are known to exert powerful influence over autonomic control during exposure to hypercapnia and hypoxia, respectively. However, the contributionofchemoreceptorstotheautonomic response to exercise, and thus its influence on the cardiovascular response to exercise, has not received much attention. Stickland et al. (2007) showed for the first time that the inhibition of carotid chemoreceptors by closed-carotid infusion of dopamine or hyperoxic Ringer solution at rest did not change blood flow and conductance in the hindlimb of healthy dogs, but caused an immediate vasodilatory response in the hindlimb of dogs with heart failure. During mild exercise, inhibitionofcarotidchemoreceptorscaused vasodilatation in the hindlimb of both healthy dogs and dogs with heart failure. In addition, it was shown that this response was entirely attributed to a decrease in the sympathetic restraint of skeletal muscle blood flow during exercise, since the vasodilatory response was abolished after infusion of an alpha adrenergic blocker (phentolamine) both in healthy dogs and in dogs with heart failure. Thereafter,Sticklandetal.(2008)elegantly translated these findings to exercising healthy humans. They showed that the transient inhibition of the carotid chemoreceptors by inhalation of hyperoxic gas during dynamic handgrip exercise reduced muscle sympathetic nerve activity (MSNA) by approximately 35%, while the transient stimulation of the carotid chemoreceptors by inhalation of hypoxic gas increased MSNA with a similar time delay to that obtained with carotid chemoreceptors inhibition via hyperoxia. Hence, these results highlighted the important role of the carotid chemoreflex in regulating the sympathoexcitation during exercise in healthy humans. Nonetheless, at this point, it was not known if the carotid chemoreceptors indeed influence skeletal muscle bloodflowandvascularconductanceduring exercise in humans.

Clinical assessments of increased sensory sensitivity in dogs with cranial cruciate ligament rupture

Dogs with chronic pain have a compromised quality of life. Repeatable and accurate sensory assessments form a means by which the hypersensitivity likely to reflect chronic pain may be quantified. These assessments can be applied to individuals to identify those that may benefit from improved analgesic relief. In this study four sensory assessments were evaluated in dogs presenting with a naturally occurring chronic painful condition (cranial cruciate ligament rupture, CCLR) and were compared with healthy control animals of similar age and weight. Inter-digital von Frey filament and thermal sensitivity tests revealed that the affected hind limb of dogs with CCLR was significantly more sensitive than the opposing limb. Static weight bearing and gait parameter scores were also reduced in the affected hind limb compared to the opposing hind limb of dogs with CCLR; no such differences were found between the hind limbs of healthy (control) dogs. The quantitative sensory tests permitted the differentiation of limbs affected by CCLR from healthy limbs. Dogs presenting with CCLR demonstrate objectively quantitative sensory sensitivities, which may require additional consideration in case management.

Immediate physical therapy in dogs with rupture of the cranial cruciate ligament submitted to extracapsular surgical stabilization

The study evaluated the influence of immediate physical therapy on the functional recovery of hind limbs of dogs with experimental cranial cruciate ligament rupture which underwent surgical extracapsular stabilization as well as to verify its interference in joint stability. Eight dogs were randomly divided into two groups: GI (control) (n=4) and GII (physical therapy) (n=4). The dogs in GII underwent the following therapeutic treatments in the postoperative period: cryotherapy, passive joint movement, massage, passive straightening, neuromuscular electrical stimulation, hydrotherapy (bath and aquatic mat) and therapeutic exercises. We performed evaluations of the thigh circumference, goniometry, X-ray, and knee stability (drawer test). Results did not demonstrate a significant difference between the groups nor between different post-operative times. Regarding gait analysis, we found that the 4 dogs in GI remained in degree 3 of lameness 45 and 90 days postoperatively. However, in GII, one dog remained in degree 3 45 and 90 days after surgery; one dog changed from degree 3 to 4 90 days after surgery and the other 2 dogs changed from degree 3 to 5 90 days after surgery. It is possible to conclude that dogs with CCL rupture that undergo immediate physical therapy demonstrate better results in regards to functional gait recovery. The therapeutic modalities used in the immediate post-operative period did not cause instability of the operated knee. Further studies are needed with a larger number of dogs to indicate the immediate physical therapy in dogs with CCL ligament rupture which underwent extracapsular stabilization.