Pressure algometry measurement of canine muscular pain near the thoracolumbar junction: evaluation of a modified technique

Quantitative sensory testing in canine musculoskeletal pain: Findings from a systematic review, meta-analysis feasibility assessment, and limitations

Quantitative sensory testing (QST) allows the study of pain mechanisms, patient phenotyping, and response to therapy. The goals of this study were to conduct a systematic review of the use of QST in dogs with musculoskeletal disease including osteoarthritis (OA), and to assess, by means of a meta-analysis, the ability of QST to differentiate affected dogs from healthy controls. The study protocol was registered; three bibliographic databases were screened. Studies involving QST in healthy dogs and those with musculoskeletal disease were included. Data were extracted using a standardized form. Assessment of quality and risk of bias were performed using the CAMARADES critical assessment tool. Twenty-nine articles met the inclusion criteria [systematic review (n = 11); meta-analysis (n = 28)]. In the systematic review, ten studies performed static QST: mechanical [punctate tactile (n = 6); mechanical pressure (n = 5)]; thermal [cold (n = 3); hot (n = 4)]; electrical (n = 1); and one study performed dynamic QST [conditioned pain modulation (n = 1)]. Most studies were of good scientific quality and showed low to moderate risk of bias. A meta-analysis was not possible due to numerous and severe issues of heterogeneity of data among studies. Methods to reduce risk of bias and use of reporting guidelines are some of the most needed improvements in QST research in dogs. Standardization of QST methodology is urgently needed in future studies to allow for data synthesis and a clear understanding of the sensory phenotype of dogs with and without chronic pain including OA.

A Multidimensional Evaluation of the Factors in the Animal Welfare Assessment Grid (AWAG) That Are Associated with, and Predictive of, Behaviour Disorders in Dogs

Behavioural disorders in dogs are common and have severe welfare consequences for dogs. This study aimed to assess the factors that are significant and predictive of behaviour problems in dogs using the animal welfare assessment grid (AWAG) to further understand what factors influence their welfare. 177 AWAG assessments were undertaken across 129 dogs that clinicians deemed to have a behavioural disorder. Wilcoxon rank-sum tests were used to assess the difference in scores between dogs with behaviour disorders and a cohort of healthy dogs (n = 117). This analysis showed that all physical factors besides body condition, all procedural factors besides procedure pain, and all psychological, and environmental factors were significantly different between healthy dogs and dogs with behaviour disorders. Spearman rank correlation coefficient (RS) revealed several significant strong positive correlations including the procedural impact on the dog's daily routine with aggression towards unfamiliar people and procedure pain, as well as other correlations between the dog's behaviour during assessment with the frequency at which they encounter fears and anxieties, clinical assessment and procedure pain, and reaction to stressors and social interactions. These findings highlight the interdependent nature of the various influences of welfare. Logistic regression analysis identified that aggression towards the caregiver, fears and anxieties frequency, and choice, control, and predictability were all significant predictors of behaviour disorders. The findings have important implications for veterinary, behaviour, and animal welfare professionals as any changes across these factors may indicate poor welfare linked to emotional disorders in dogs.

Location of Trigger Points in a Group of Police Working Dogs: A Preliminary Study

This study examined the percentage and location of trigger points in police working dogs. Twelve dogs housed at a military police kennel were selected through convenience sampling. Only active dogs with no comorbidities or radiographic changes doing 6 hours of intense physical activity per day were included. After orthopedic and neurological examination, dogs were palpated for the detection of trigger points (TPs), carried out by two independent examiners, with criteria of palpations previously standardized. TPs were recorded using an anatomy reference image according to the corresponding anatomical location. The percentage of TPs was highest in the lumbar portion of the longissimus dorsi muscle (42%), followed by the latissimus dorsi, pectineus, quadriceps femoris, and sartorius (33%) muscles. Most TPs were located on the right side of the body. This study's percentage of TPs in police working dogs was higher in spinal and hind limb muscles, especially on the right side. The major criteria for identifying TPs in dogs were the pain responses to palpation and contractile local response. The findings of this study could be used to refine myofascial pain prevention to reduce early retirement due to musculoskeletal pain and draw attention to this kind of problem that can also affect dogs.

Contribution to the Study of Perioperative Factors Affecting the Restoration of Dog's Mobility after Femoral Head and Neck Excision: A Clinical Study in 30 Dogs

This study aimed to compare postoperative analgesia and the time of limb weight bearing induced by the intraoperative administration of a local anesthetic at the site of the femoral head and neck excision (FHNE) in dogs, with and without the administration of preoperative epidural anesthesia. Additionally, the impact of postoperative opioid drug administration on weight-bearing time was examined. This randomized, blinded, prospective clinical study included 30 client-owned dogs. The dogs were randomly divided into three groups (A, B, C), each further divided into two subgroups (A1, A2, B1, B2, C1, C2). Group A received epidural anesthesia and ropivacaine at the ostectomy site, Group B received only ropivacaine, and Group C served as the control group. Subgroup 1 received a non-steroidal anti-inflammatory drug postoperatively, while Subgroup 2 had tramadol added to their regimen. Pain assessment was conducted using the University of Melbourne Pain Scale (UMPS) and an algometer. The study concluded that multimodal analgesia, utilizing all the aforementioned analgesic techniques, resulted in faster limb weight bearing for dogs undergoing FHNE.

Efficacy of autologous mesenchymal stromal cell treatment for chronic degenerative musculoskeletal conditions in dogs: A retrospective study

Introduction

The objective of this study was to retrospectively analyze clinical data from a referral regenerative medicine practice, to investigate the efficacy of autologous mesenchymal stromal cells (MSC) in 245 dogs deemed unresponsive to conventional treatment by their referring vet.

Methods

Diagnostic imaging [radiology and musculoskeletal ultrasound (MSK-US)] identified musculoskeletal pathology holistically. MSCs, produced according to current guidelines, were initially administered with PRP by targeted injection to joints and/or tendons, with a second MSC monotherapy administered 12 weeks later to dogs with severe pathology and/or previous elbow arthroscopic interventions. Dogs with lumbosacral disease received epidural MSCs with additional intravenous MSCs administered to dogs with spondylosis of the cervical, thoracic and lumbar spine. All dogs received laser therapy at 10 J/cm² at the time of treatment and for 5 sessions thereafter. Objective outcome measures (stance analysis, range of joint motion, pressure algometry) and validated subjective outcome measures (owner reported VetMetrica HRQL™ and veterinary pain and quality of life impact scores) were used to investigate short and long-term (6-104 weeks) efficacy. Outcome data were collected at predetermined time windows (0-6, 7-12, 13-18, 19-24, 25-48, 49-78, 79-104) weeks after initial treatment.

Results

There were statistically significant improvements in post compared with pre-treatment measures at all time windows in stance analysis, shoulder and hip range of motion, lumbosacral pressure algometry, and to 49-78 weeks in carpus and elbow range of motion. Improvements in 4 domains of quality of life as measured by VetMetricaTM were statistically significant, as were scores in vet-assessed pain and quality of life impact. In dogs receiving one initial treatment the mean time before a second treatment was required to maintain improvements in objective measures was 451 days. Diagnostic imaging confirmed the regenerative effects of MSCs in tendinopathies by demonstrating resolution of abnormal mineralization and restoration of normal fiber patterns.

Discussion

This represents the first study using "real-world" data to show that cell-based therapies, injected into multiple areas of musculoskeletal pathology in a targeted holistic approach, resulted in rapid and profound positive effects on the patient's pain state and quality of life which was maintained with repeat treatment for up to 2 years.

Clinical assessment and grading of back pain in horses

Background

The clinical presentation of horses with back pain (BP) vary considerably with most horse's willingness to take part in athletic or riding purpose becoming impossible. However, there are some clinical features that are directly responsible for the loss or failure of performance.

Objectives

To investigate the clinical features of the thoracolumbar region associated with BP in horses and to use some of the clinical features to classify equine BP.

Methods

Twenty-four horses comprised of 14 with BP and 10 apparently healthy horses were assessed for clinical abnormality that best differentiate BP from normal horses. The horses were then graded (0–5) using the degree of pain response, muscular hypertonicity, thoracolumbar joint stiffness and overall physical dysfunction of the horse.

Results

The common clinical features that significantly differentiate horses with BP from non-BP were longissimus dorsi spasm at palpation (78.6%), paravertebral muscle stiffness (64.3%), resist lateral bending (64.3%), and poor hindlimb impulsion (85.7%). There were significantly (p < 0.05) higher scores for pain response to palpation, muscular hypertonicity, thoracolumbar joint stiffness and physical dysfunction among horses with BP in relation to non-BP. A significant relationship exists between all the graded abnormalities. Based on the cumulative score, horses with BP were categorized into mild, mild-moderate, moderate and severe cases.

Conclusions

BP in horse can be differentiated by severity of pain response to back palpation, back muscle hypertonicity, thoracolumbar joint stiffness, physical dysfunctions and their cumulative grading score is useful in the assessment and categorization of BP in horses.

Pressure Algometry Validation and Determination of Efficacy of Articaine Hydrochloride Ring Block in Antler Removal in Red Deer (Cervus elaphus)

Simple Summary

Red deer (Cervus elaphus) are farmed in New Zealand for the production of velvet antler. Velvet is harvested as living antler tissue, and currently lignocaine is the only licensed local anaesthetic approved for deer antler removal in New Zealand. The use of lignocaine is not without consequences, including drug residues in harvested velvet antler tissue and its short acting analgesic effect. This study was designed to determine the effect of local anaesthetic, articaine hydrochloride as an alternative treatment and to establish the baseline measurements of mechanical nociceptive threshold in 40 male yearling red deer. Ten of the forty enrolled deer were selected for the articaine efficacy study. The mechanical nociceptive thresholds were measured using a handheld algometer applied at 4 points; the cranial, medial, caudal and lateral aspects of the base of each antler. The force applied, which resulted in a movement by the animal, was recorded in newtons (N). This study showed that nociceptive threshold response in deer could be reliably measured, and articaine proved to be a promising alternative for velveting the deer antlers.

Abstract

New Zealand deer farming centres on the production of meat and velvet antler. Velvet antler removal is a painful procedure and currently, New Zealand Animal Welfare regulations dictate surgical removal of velvet antlers under lignocaine anaesthesia. To improve our knowledge on the efficacy and duration of other local anaesthetics to mitigate pain after antler removal, it is important to accurately assess and quantify pain arising from antler removal. Therefore, the current study was designed to validate mechanical nociceptive threshold (MNT) testing using a Wagner hand-held algometer, and to apply this methodology to assess the efficacy and duration of action of articaine for antler removal in deer. Baseline force (N) required to elicit the nociceptive response was recorded in 40 yearling male red deer on three alternate days. Ten of the 40 animals were selected for antler removal after administration of 4% articaine hydrochloride as a ring block. The duration of analgesic efficacy of articaine was assessed by algometry across 5 time points. There was a significant difference in MNTs among the three days (day 3 versus day 1 (p < 0.0001), day 2 versus day 1 (p < 0.0001), and day 1 versus day 2 (p < 0.01)). Positive correlations were observed between weight, antler length and thresholds. The MNT values remained above 20N for 6 h after removal of velvet antlers under the articaine ring block. This study provides valuable information about the use of MNT in red deer. These findings lay a foundation for future studies in the topics of peri-operative and postoperative pain management in deer antler removal, and a possible alternative use for articaine.

Long-term postoperative pain evaluation in dogs with thoracolumbar intervertebral disk herniation after hemilaminectomy

BACKGROUND

Chronic neuropathic pain is a common complication in people with spinal cord injury (SCI) but has not been investigated in dogs.

OBJECTIVE

To determine the reliability of measuring spinal mechanical sensory thresholds (MSTs) in dogs and to compare MSTs of healthy dogs and dogs with SCI caused by acute thoracolumbar intervertebral disk extrusion after hemilaminectomy over a 1-year period.

STUDY DESIGN

Prospective study.

ANIMALS

Thirty-two healthy and 40 SCI dogs.

METHODS

Dogs were divided into group 1 (healthy Dachshunds), group 2 (healthy dogs including several breeds), and SCI group. The MSTs were measured using algometry at an incision (thoracolumbar) and control site. Dogs in group 1 were tested once; those in group 2 were tested for 5 consecutive days; and SCI dogs were tested on days 7, 14, 28, 42, 180, and 365 postoperatively. The MSTs were compared among days in healthy and SCI dogs and between SCI and healthy dogs using mixed effect models. P < .05 was considered significant.

RESULTS

At the incision site of SCI dogs, MST was significantly lower than in healthy dogs for 42 days postoperatively, but not subsequently. However, 4/27 dogs had control site MST below the reference range 1 year after surgery.

CONCLUSIONS AND CLINICAL IMPORTANCE

Mechanical sensory thresholds normalize by 6 months after surgery in most dogs with SCI. Approximately 15% of SCI dogs may develop chronic neuropathic pain. Improving long-term pain assessment of SCI dogs is important for offering treatment options and advising owners.

Pressure algometry for assessment of abdominal wall sensitivity in horses after ventral midline coeliotomy

OBJECTIVE

To assess the clinical course of abdominal wall sensitivity after ventral midline coeliotomy in horses by determining mechanical nociceptive thresholds (MNTs) during hospitalization, and to determine the inter-observer reliability of pressure algometry on the abdominal wall.

STUDY DESIGN

Observational, cohort study.

SAMPLE POPULATION

A total of 13 horses presenting with signs of abdominal pain/colic undergoing ventral midline coeliotomy and 10 healthy horses without an abdominal incision.

METHODS

Measurements were performed on days 1, 3, 5, 7 and 9 postoperatively using a pressure algometer. Measurement sites were marked left and right, abaxial to the abdominal incision. Cranial to the incision, two control points were marked. Measurements were made by one observer, blinded to the recorded MNT values. To determine inter-observer reliability, five horses (surgical group n = 2; nonsurgical group n = 3) were measured by two observers in a randomized order.

RESULTS

Mean MNT values on days 5 and 7 were 9.61 Ncm^-2 and 10.14 Ncm^-2 in the operated group (p = 0.009 ; p = 0.005) respectively versus 13.00 Ncm^-2 on day 1. Wound-associated points showed lower values than control points (p = 0.002). The nonsurgical group did not show a difference between control points and wound-associated points (p = 0.06). No significant differences were found between the surgical and the nonsurgical groups at the wound-associated points on any days measured. The inter-observer reliability was low (intraclass correlation coefficient of 0.26; Cronbach's alpha of 0.27).

CONCLUSION

Operated animals showed a reduction in MNT values on days 5 and 7 when compared with day 1 and lower values for the wound-associated points when compared with the control points. Inter-observer reliability was low. Pressure algometry could be a useful tool for assessing wound sensitivity after ventral midline coeliotomy in horses, which may improve pain management postoperatively.

Use of topical local anesthetics to control pain during treatment of hoof lesions in dairy cows

Hoof pathologies in dairy cows have a major effect on both production and animal welfare. Trimming of excess or diseased hoof tissue is essential for the treatment of many of these conditions. Trimming hoof lesions can cause severe pain, resulting in adverse behavioral responses with risk for animal and human safety. Interventions are usually carried out by nonveterinary technicians in the absence of pain management training. Pain control during trimming is not only an ethical obligation but also allows for better manipulation and more meticulous treatment. The aim of this study was to test the efficacy of Tri-Solfen (Bayer Australia Ltd., Pymble, NSW, Australia), a combination of local anesthetics in a topical gel form, containing lidocaine, bupivacaine, adrenaline, and cetrimide, for the treatment of pain associated with trimming of hoof lesions. Sixty-two Holstein-Frisian cows were selected for trimming at the drying-off period and were visually scored for lameness before entering the chute. After diagnosis of the hoof lesion but before deep trimming was initiated, each animal was randomly distributed to 2 groups: C, usual trimming with no pain control, and T, trimming with a local anesthetic formulation being applied immediately after live corium was exposed. During curative trimming, behavior observation was conducted by 2 observers blind to treatment. In 27 cows, algometry measurements were performed before and after the procedure to assess animal reaction to pressure. Lameness scoring was again performed as the cow left the chute. Nonparametric tests and ANOVA were performed. Results showed that use of the topical anesthetic formulation significantly reduced reaction to trimming and lameness score after trimming when compared with nontreated animals. Algometry values showed increased pressure threshold after application of topical anesthetics. This study suggests that the use of topical local anesthesia with lidocaine and bupivacaine helps reduce pain associated with corrective trimming of severe hoof lesions, enhancing animal welfare and potentially ensuring safety of trimmers.

Pain characterization and response to palliative care in dogs with naturally-occurring appendicular osteosarcoma: An open label clinical trial

This study aimed to characterize bone cancer pain (quantitative sensory testing (QST), stance asymmetry index, actimetry, scores of pain and quality of life (QoL)) in dogs with appendicular osteosarcoma (OSA), and to evaluate a stepwise palliative analgesic treatment.

The pain profile of thirteen client-owned dogs with OSA was compared with seven healthy dogs. Dogs with OSA were then enrolled in a prospective, open-label, clinical trial. Outcome measures included: primary and secondary mechanical thresholds (MT), conditioned pain modulation (CPM), stance asymmetry index, actimetry (most and least active periods), visual analog scales and QoL. After baseline assessments, stepwise treatment comprised orally administered cimicoxib (2 mg/kg q 24h), amitriptyline (1–1.5 mg/kg q 24h) and gabapentin (10 mg/kg q 8h); re-evaluations were performed after 14 (D14), 21 (D21) and 28 (D28) days, respectively. Statistics used mixed linear models (α = 5%; one-sided). Centralized nociceptive sensitivity (primary and secondary MT, and dynamic allodynia) was recorded in OSA dogs. Healthy dogs had responsive CPM, but CPM was deficient in OSA dogs. Construct validity was observed for the QST protocol. Asymmetry index was significantly present in OSA dogs. The CPM improved significantly at D14. When compared with baseline (log mean ± SD: 4.1 ± 0.04), most active actimetry significantly improved at D14 (4.3 ± 0.04), D21 and D28 (4.2 ± 0.04 for both). When compared with baseline, least active actimetry significantly decreased after treatment at all time-points indicating improvement in night-time restlessness. No other significant treatment effect was observed. Except for tactile threshold and actimetry, all outcomes worsened when gabapentin was added to cimicoxib-amitriptyline. Dogs with bone cancer are affected by widespread somatosensory sensitivity characterized by peripheral and central sensitization and have a deficient inhibitory system. This severe pain is mostly refractory to palliative analgesic treatment, and the latter was only detected by specific and sensitive outcomes.

Effects of hyaluronidase on ropivacaine or bupivacaine regional anaesthesia of the canine pelvic limb

OBJECTIVE

To determine the effect of hyaluronidase on time to onset and offset of anaesthesia in ropivacaine or bupivacaine femoral-ischiatic nerve blocks.

STUDY DESIGN

Blinded randomized crossover trial.

ANIMALS

Eight dogs.

METHODS

Each dog underwent four treatments separated into two blocks - initially, the ropivacaine treatment block: RS (ropivacaine 0.5% plus saline 0.9%) and RH (ropivacaine 0.5% plus hyaluronidase 100 IU mL^-1), followed 3 weeks later by the bupivacaine treatment block: BS (bupivacaine 0.5% plus saline) and BH (bupivacaine 0.5% plus hyaluronidase). The local anaesthetics were administered at 0.1 mL kg^-1 per site. Hyaluronidase and saline were administered at 0.02 mL kg^-1 per site. Performance of femoral-ischiatic blocks was aided by a combined ultrasound-electrolocation technique. The mechanical nociceptive threshold was measured, until offset or 360 minutes, using an algometer to ascertain baseline, onset and offset of anaesthesia. Onset and offset of anaesthesia were defined as a 25% increase above and as a return to <25% above baseline nociceptive threshold readings, respectively.

RESULTS

The median (range) onset of anaesthesia for RS and RH was 21 (3-60) and 12 (3-21) minutes, respectively (p = 0.141), and offset was 270 (90-360) and 180 (30-300) minutes, respectively (p = 0.361). By contrast, the median (range) onset of anaesthesia for BS and BH was 24 (3-60) and 9 (3-27) minutes, respectively (p = 0.394), and offset was 360 (240-360) and 330 (210-360) minutes, respectively (p = 0.456).

CONCLUSION AND CLINICAL RELEVANCE

Hyaluronidase had no effect on the onset and offset times of ropivacaine and bupivacaine femoral-ischiatic nerve blocks in dogs compared with saline. The onset and offset times were highly variable in all treatments. Clinically, the high variability of the onset and offset times of the regional anaesthesia of these local anaesthetic drugs means that clinicians must monitor the animal's response and, if required, provide additional analgesic drugs.

Acute pain and peripheral sensitization following cautery disbudding in 1- and 4-week-old calves

Acute pain and peripheral sensitization development after cautery disbudding was investigated in 33 calves administered preventive multimodal analgesia. The animals were assigned randomly to three groups: 1) Group SH (Control), undergoing sham disbudding at 1 and 4weeks of age; 2) Group ED (Early Disbudding), undergoing disbudding at 1week of age and sham disbudding at 4weeks of age; 3) Group LD (Late Disbudding), undergoing sham disbudding at 1week of age and disbudding at 4weeks of age. Physiological parameters (heart rate, respiratory rate, rectal temperature, invasive blood pressure, cortisol, β-endorphin, interleukin-1β, interleukin-6, tumor necrosis factor-α and haptoglobin plasmatic concentration), local variables (tactile sensitivity score, pressure pain thresholds and horn temperature), behavior and pain scores [multidimensional pain scale and visual analogue scale (VAS)] were assessed at baseline and at several pre-determined time points until 24h after disbudding. Tactile sensitivity score significantly and equally increased in both groups ED and LD and pressure pain thresholds significantly decreased in group LD until 24h after disbudding compared to group SH. Pain and VAS scores significantly and equally increased in both groups ED and LD until 24h after disbudding compared to group SH. No significant differences in physiological parameters, behavior and horn temperature were detected among groups. The present study suggests that acute pain and peripheral sensitization develop and do not differ in calves disbudded at 1week and 4weeks of age. Moreover, the use of physiological and behavioral parameters as sole indicators of acute pain might lead to improper conclusions and should be reassessed.

Integrative veterinary medical education and consensus guidelines for an integrative veterinary medicine curriculum within veterinary colleges

Integrative veterinary medicine (IVM) describes the combination of complementary and alternative therapies with conventional care and is guided by the best available evidence. Veterinarians frequently encounter questions about complementary and alternative veterinary medicine (CAVM) in practice, and the general public has demonstrated increased interest in these areas for both human and animal health. Consequently, veterinary students should receive adequate exposure to the principles, theories, and current knowledge supporting or refuting such techniques. A proposed curriculum guideline would broadly introduce students to the objective evaluation of new veterinary treatments while increasing their preparation for responding to questions about IVM in clinical practice. Such a course should be evidence-based, unbiased, and unaffiliated with any particular CAVM advocacy or training group. All IVM courses require routine updating as new information becomes available. Controversies regarding IVM and CAVM must be addressed within the course and throughout the entire curriculum. Instructional honesty regarding the uncertainties in this emerging field is critical. Increased training of future veterinary professionals in IVM may produce an openness to new ideas that characterizes the scientific method and a willingness to pursue and incorporate evidence-based medicine in clinical practice with all therapies, including those presently regarded as integrative, complementary, or alternative.