Dose Reduction of Meloxicam in Dogs with Osteoarthritis-Associated Pain and Impaired Mobility

Psychometric Testing and Validation of the Italian Version of the Helsinki Chronic Pain Index (I-HCPI) in Dogs with Pain Related to Osteoarthritis

Pain assessment is of paramount importance for properly managing dogs with osteoarthritis (OA) pain. The aim of the present study was to develop and psychometrically validate the Italian version of the Helsinki Chronic Pain Index (I-HCPI). Owners of OA painful (n = 87) and healthy dogs (n = 40) were administered the I-HCPI once or twice after an eight-week meloxicam treatment. Sixty-nine owners of healthy and OA dogs also completed the Italian version of the Canine Brief Pain Inventory (I-CBPI). Pain on palpation on a 0-4 scale was assessed on all recruited dogs. Construct validity was tested both with hypothesis testing and principal component analysis, confirming the I-HCPI accurately measured chronic pain. Good convergent and criterion validity were shown through correlations with I-CBPI subscores and distribution among pain on palpation scores (p < 0.0001). The significant difference between the pre- and post-treatment I-HCPI scores (p < 0.0001) and Cohen's effect size (2.27) indicated excellent responsiveness. The I-HCPI was shown to be reliable through communalities (range 0.47-0.90) and Cronbach α (≥0.95). Discriminative ability and cut-off point, as tested through Receiver Operating Characteristic analysis, showed excellent diagnostic accuracy with a threshold value of 11 (specificity 0.98 and sensitivity 0.94). The I-HCPI was confirmed to be a valid, sensitive, reliable, and accurate tool to discriminate between dogs with and without pain.

Using network analysis to detect associations between suspected painful health conditions and behaviour in dogs

Pain associated with chronic health conditions in non-human animals is an important animal welfare issue. To identify animals in pain and develop an understanding of the mechanisms by which pain affects behaviour, it is therefore important to establish the direct behavioural effects of painful health conditions. We reanalyse data from a cross-sectional survey that considered the presence or absence of a painful condition in dogs and quantified their affective predispositions using the Positive and Negative Activation Scale (PANAS). By applying ideas from network theory, we conceptualise pain as a stressor that exerts direct effects on a network of interacting behavioural variables, and subsequently estimated a network model of conditional dependence relations. Painful health conditions were positively conditionally associated with age (posterior mean partial correlation, ρ = 0.34; standard deviation [SD]=0.05), and negatively conditionally associated with the item 'your dog is full of energy' (ρ = -0.14; SD=0.06). In turn, the energy item was conditionally associated with other PANAS items which were marginally associated with pain, such as items representing ease of excitability and persistence in play. This suggests these marginal effects might be indirectly mediated via the energy item. Further, utilising the posterior predictive distribution we estimated that the median conditional probability (95% credible interval) of a painful health condition given an answer of 'strongly agree' on the energy item was 0.08 (0.05, 0.11), which increased to 0.32 (0.09, 0.58), given a response of 'strongly disagree'. This provides a potentially clinically useful interpretation of the conditional dependencies detected in the network.

Effects of low-level laser therapy on impaired mobility in dogs with naturally occurring osteoarthritis

BACKGROUND

Osteoarthritis is common in the aging dog and is associated with chronic pain and impaired mobility. The main objective of this study was to determine whether low-level laser therapy (LLLT) would increase physical activity in dogs with osteoarthritis.

METHODS

Twenty-three dogs with osteoarthritis were instrumented with an accelerometer 48 h before the first LLLT session (baseline), to record daily activity. Each dog underwent six consecutive weekly laser treatments. The scores of the Canine Brief Pain Inventory and the Liverpool Osteoarthritis in Dogs' were recorded for clinical purposes, as a tool to titrate the analgesic therapy of each individual dog, before LLLT (as baseline) and then weekly for 6 weeks.

RESULTS

The number of daily activities increased during week 2 (161,674; SD, 103,666) and remained higher than baseline (93,481; SD, 107,878) until week 6 (179,309; SD, 126,044; p < 0.001). Daily step count increased from week 1 (4472; SD, 3427) compared to baseline (1109; SD, 1061) and remained higher than the baseline until the end of week 6 (8416; SD, 3166; p < 0.001). Average energy expenditure during the study period was 179 [range, 2-536] kcal/day; there were no statistically significant differences in this variable between weeks of treatment. Systemic analgesics therapy was decreased in 50% of the dogs during the study period.

CONCLUSIONS

Laser therapy may advance the management of osteoarthritis by increasing the level of activity of dogs, therefore improving their quality of life.

Nine-axis inertial measurement unit output discriminates activities of varying intensity in the dog

OBJECTIVE

To explore relationships between 9-axis inertial measurement unit (IMU) output and activities of varying intensity in dogs of various sizes.

ANIMALS

20 healthy, agility course-trained dogs of various ages and sizes.

PROCEDURES

Height, weight, body condition score, age, length from IMU to the ischium, and height of IMU to the floor were recorded. Dogs performed a series of activities (rest, walk, trot, and agility course) while wearing the IMU device. IMU and video output were reviewed by independent investigators. Correlations and multiple regression models were used to explore relationships between independent variables and IMU output.

RESULTS

Calibration demonstrated excellent correlation and concordance between IMUs (intraclass correlation > 0.9) and that the IMUs reliably measured a known acceleration (gravity at rest). Resultant vector magnitude {sqrt[(x^2) + (y^2) + (z^2)]} normalized to body size was calculated from the data. IMU output clearly discriminates between activities of varying intensity in the dog.

CLINICAL RELEVANCE

The inability to accurately measure chronic pain is a barrier to the development of new, or critical evaluation of, therapeutics. Activity monitors (AM) may be the ideal diagnostic target since they are small and provide objective data that can be collected while the pet remains in its natural environment. These results demonstrate the concurrent and predictive validity of the IMU tested. Our long-range goal is to validate an open-source algorithm for the IMU so activity in a pet's natural environment can be used as an outcome measure in future studies.

Palmitoyl-glucosamine co-micronized with curcumin for maintenance of meloxicam-induced pain relief in dogs with osteoarthritis pain

BACKGROUND

Osteoarthritis (OA) pain is the number one cause of chronic pain in dogs. Multimodal treatment, including combining safe and effective nutritional interventions with non-steroidal anti-inflammatory drugs (NSAIDs), is currently considered one of the most appropriate choices for managing OA pain. Palmitoyl-glucosamine is a feed material belonging to the ALIAmide family, whose parent molecule is the prohomeostatic lipid amide N-palmitoyl-ethanolamine. Curcumin is a promising plant antioxidant. The present study aimed at investigating whether 18-week dietary integration with palmitoyl-glucosamine co-micronized with curcumin was able to maintain pain relief in dogs with OA-associated chronic pain receiving meloxicam (1.5 mg/ml oral suspension) on a tapering regimen (progressive 25% decrease of the original 0.1 mg/kg/day dose, on a biweekly basis) during the first 8 weeks of treatment. Pain was assessed both by the owners and veterinary surgeons, with the first using both subjective evaluation and validated metrology instruments-i.e., Helsinki Chronic Pain Index (HCPI) and Canine Brief Pain Inventory (CBPI)-while the second rating the severity of lameness and pain on palpation on two previously used 5-point scales.

RESULTS

A total of fifty-eight dogs with OA chronic pain entered the uncontrolled study. Pain on HCPI was considered severe at baseline (range 18-39). Based on owner's assessment, 90% of dogs who responded to meloxicam at the full-dose regimen could reduce meloxicam up to 25% of the original dose without experiencing pain worsening. Moreover, 75% of dogs was assessed as having no pain increase ten weeks after meloxicam withdrawal. A statistically significant decrease of pain severity as scored by HCPI (P < 0.0001) was observed two and ten weeks after meloxicam withdrawal compared to study entry (17.0 ± 1.05 and 15.1 ± 1.02, respectively, vs 29.0 ± 0.74; mean ± SEM). After meloxicam withdrawal, no statistically significant change in the CBPI scores was recorded. Pain on palpation and lameness significantly changed to less severe distributions along the study period (P < 0.0001).

CONCLUSION

The findings appear to suggest that dietary integration with palmitoyl-glucosamine co-micronized with curcumin was able to maintain meloxicam-induced pain relief in dogs with severe OA chronic pain.

Initial exploration of the discriminatory ability of the PetPace collar to detect differences in activity and physiological variables between healthy and osteoarthritic dogs

Background

Accelerometry has been used to evaluate activity in dogs with osteoarthritis (OA) pain, especially in relation to effect of treatment; however no studies have compared accelerometry-measured activity in dogs with OA-pain and healthy dogs. The aims of this study were to (1) compare activity output from the PetPace collar with the validated Actical monitor and (2) determine if PetPace collar outputs (overall activity, activity levels, body position, and vital signs) differed between healthy dogs and dogs with OA-pain.

Methods

This was an observational, non-interventional study in healthy dogs and dogs with OA-pain. All dogs were outfitted with the PetPace collar and the Actical monitor simultaneously for 14 days. Output from these devices was compared (correlations), and output from the PetPace device was used to explore differences between groups across the activity and vital sign outputs (including calculated heart rate variability indices).

Results

There was moderate correlation between the PetPace collar and Actical monitor output (R² = 0.56, p < 0.001). Using data generated by the PetPace collar, OA-pain dogs had lower overall activity counts and spent less time standing than healthy dogs. Healthy dogs spent more time at higher activity levels than OA-pain dogs. Certain heart rate variability indices in OA-pain dogs were lower than in healthy dogs.

Conclusions and clinical relevance

The results of this study suggest that the PetPace collar can detect differences between healthy dogs and those with OA-pain, and that OA-pain negatively impacts overall activity levels in dogs, and especially higher intensity activity.

The beneficial role of companion animals in translational pain research

The use of spontaneous painful disease in companion pet animals has been highlighted as one of the changes that could be made to help improve translation of basic science to new therapeutics, acting as a bridge between preclinical and clinical studies, with the goal of accelerating the approval of new therapeutics. This review focuses on the utility of companion pet dogs for translational research by reviewing what outcome measures can be measured, and importantly, the relevance of these outcome measures to human translational research. It also details the practical considerations involved in incorporating companion dogs into human therapeutic development.

Proposed Canadian Consensus Guidelines on Osteoarthritis Treatment Based on OA-COAST Stages 1–4

The Canadian consensus guidelines on OA treatment were created from a diverse group of experts, with a strong clinical and/or academic background in treating OA in dogs. The document is a summary of the treatment recommendations made by the group, with treatments being divided into either a core or secondary recommendation. Each treatment or modality is then summarized in the context of available research based support and clinical experience, as the treatment of OA continues to be a multimodal and commonly a multidisciplinary as well as individualized approach. The guidelines aim to help clinicians by providing clear and clinically relevant information about treatment options based on COAST defined OA stages 1–4.

Displacement of center of mass in dogs in response to foot sensory stimulation

OBJECTIVE

Evaluate center of mass (CoM) displacement values during four-limb and three-limb standing with limb suspension in dogs before and after applying sensory stimulation to a forelimb or hindlimb.

STUDY DESIGN

Experimental study.

ANIMALS

Six clinically normal beagles.

METHODS

A four force-plate apparatus was built to assess static weight distribution. Dogs stood on the device with one limb in contact with each force plate. We created a plastic device to induce sensory stimulation so that lameness could not be detected visually when stimulating the paw. Experimenters confirmed the degree of lameness by walking before and after measurement. Body-weight shifts were induced via suspension of each limb and transient sensory stimulation to the right forelimb or left hindlimb. CoMs of five postures were compared, with and without transient sensory stimulation.

RESULTS

The four-limb CoM was located cranial to the center of the X- and Y-axis coordinates (X: -0.82 ± 9.12, Y: 61.00 ± 5.82). During three-limb standing with suspension of either forelimb, CoM shifted backward toward the contralateral side compared to four-limb standing. During hindlimb suspension, CoM shifted to the contralateral side. With right forelimb sensory stimulation, there were large CoM changes for both four-limb and three-limb standing (X: -34.53 ± 9.09, Y: 52.21 ± 6.88). CoM changes were small with left hindlimb sensory stimulation (X: 6.47 ± 13.86, Y: 69.41 ± 5.55).

CONCLUSION

CoMs during four-limb and three-limb standing were influenced by sensory stimulation of a forelimb and, to a lesser extent, of a hindlimb.

CLINICAL SIGNIFICANCE

Static evaluation of CoM may aid clinicians in the diagnosis and recovery of forelimb lameness.

Evaluation of the FitBark Activity Monitor for Measuring Physical Activity in Dogs

Accelerometers track changes in physical activity which can indicate health and welfare concerns in dogs. The FitBark 2 (FitBark) is an accelerometer for use with dogs; however, no studies have externally validated this tool. The objective of this study was to evaluate FitBark criterion validity by correlating FitBark activity data to dog step count. Dogs (n = 26) were fitted with a collar-mounted FitBark and individually recorded for 30 min using a three-phase approach: (1) off-leash room explore; (2) human-dog interaction; and (3) on-leash walk. Video analysis was used to count the number of times the front right paw touched the ground (step count). Dog step count and FitBark activity were moderately correlated across all phases (r = 0.65, p < 0.001). High correlations between step count and FitBark activity were observed during phases 1 (r = 0.795, p < 0.001) and 2 (r = 0.758, p < 0.001), and a low correlation was observed during phase 3 (r = 0.498, p < 0.001). In conclusion, the FitBark is a valid tool for tracking physical activity in off-leash dogs; however, more work should be done to identify the best method of tracking on-leash activity.

Preliminary bioequivalence of an oral integrating film formulation containing meloxicam with a suspension formulation in beagle dogs

The oral disintegrating film (ODF) has advantages over suspension and tablet. These include convenience of administration, patient compliance, and accurate dosing. We evaluated the bioequivalence between the ODF and the meloxicam suspension by using a crossover design with a 3-week washout period. Six healthy male beagle dogs were randomized to receive both formulations of meloxicam, 2 mg. Plasma meloxicam concentrations were measured at the same times. From the start until maximum concentration, the initial absorption of the ODF meloxicam formulation was more rapid (2.08 ± 1.56 hr) as compared to the suspension (3.33 ± 1.03 hr). Mean elimination half-lives were 28.77 ± 4.01 and 32.85 ± 9.79 hr for the ODF and the suspension, respectively. Bioequivalence of the ODF was confirmed, based on the relative ratios of geometric mean concentrations (and 90% confidence intervals within the range of 80%-125%) for a maximum concentration of 101.05% (88.59-115.25), for the area under the plasma concentration-time curve (AUC) to the last sampling time of 96.07% (87.06-115.25), and for AUC to infinity of 92.65% (86.76-98.94). The meloxicam ODF may be used as an alternative to suspension formulations in the treatment of inflammatory joint diseases and painful musculoskeletal disorders.

Novel use of an activity monitor to model jumping behaviors in cats

OBJECTIVE

To develop methods to identify and characterize activity monitor (AM) data signatures for jumps performed by cats.

ANIMALS

13 healthy, client-owned cats without evidence of osteoarthritis or degenerative joint disease.

PROCEDURES

Each cat was fitted with the same AM, individually placed in an observation room, then simultaneously recorded by 3 video cameras during the observation period (5 to 8 hours). Each cat was encouraged to jump up (JU), jump down (JD), and jump across (JA) during the observation period. Output from the AM was manually annotated for jumping events, each of which was characterized by functional data analysis yielding relevant coefficients. The coefficients were then used in linear discriminant analysis to differentiate recorded jumps as JUs, JDs, or JAs. To assess the model's ability to distinguish among the 3 jump types, a leave-one-out cross-validation method was used, and the misclassification error rate of the overall categorization of the model was calculated.

RESULTS

Of 731 jumping events, 29 were misclassified. Overall, the mean misclassification error rate per cat was 5.4% (range, 0% to 12.5%), conversely indicating a correct classification rate per cat of 94.6%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the model was successful in correctly identifying JUs, JDs, and JAs in healthy cats. With advancements in AM technology and data processing, there is potential for the model to be applied in clinical settings as a means to obtain objective outcome measures.

Evaluation of a collar-mounted accelerometer for detecting seizure activity in dogs

Background

The majority of dogs with idiopathic epilepsy continue to have seizures despite appropriate treatment.

Objectives

To assess the use of a commercially available, collar‐mounted accelerometer to detect generalized seizures in dogs.

Animals

Twenty two client‐owned dogs with idiopathic epilepsy.

Methods

Six‐month prospective clinical study during which dogs wore a collar‐mounted accelerometer. Seizure documentation was based on owner observations and video recordings. The accelerometer used a predefined algorithm to detect seizures in the first study phase, and an individualized algorithm in the second study phase. Caregivers completed a quality of life (QoL) questionnaire at the initial and final study visit.

Results

Using the predefined algorithm, the accelerometer detected seizures with a sensitivity of 18.6% (95% CI [13.4%, 23.8%]) and mean false detection rate of 0.096/day. Values did not change significantly with use of an individualized algorithm (sensitivity 22.1%, 95% CI [15.1%, 29.0%]; false detection rate 0.054/day). Mean composite QoL score was significantly improved at study completion (50.42) compared to study initiation (39.53; P = .005), and this change was moderately correlated with a change in weekly exercise (r = 0.46, P = .05).

Conclusions and Clinical Importance

Generalized seizures in dogs can be detected with a collar‐mounted accelerometer, but the overall sensitivity is low.

Investigating the Probability of Response Bias in Owner-Perceived Pain Assessment in Dogs With Osteoarthritis

Owners' ability to recognize signs of chronic pain in dogs undergoing pharmacologic and nonpharmacologic pain interventions during a period of physical rehabilitation is not known. This study aimed to compare dogs with and without chronic pain, and to assess the relationship between explanatory factors, including the probability of owners' response bias induced by pharmacologic and nonpharmacologic pain intervention, and chronic pain in dogs with osteoarthritis (OA). Seventy-one dogs with OA were included in this observational study. Owner-perceived pain interference was measured by Canine Brief Pain Inventory (CBPI) and owner-perceived pain behavior was assessed using Helsinki Chronic Pain Index. A dichotomous variable of Helsinki Chronic Pain Index was used in regression analysis to investigate the association between chronic pain and explanatory factors (body condition, anti-inflammatory medication, animal physiotherapy consultation once or more and owners' perception of pain interfering). Seventy-five percent of the dogs had ongoing anti-inflammatory medication, 51% of were overweight and 45% had a physiotherapy consultation. Higher levels of overt pain behaviors were reported in items addressing activities. Body condition, physiotherapy consultation and medication were not associated with chronic pain. Odds ratio (OR) and 95% confidence intervals of OR for the CBPI were 1.74 (1.23-2.47) and significantly associated with chronic pain. The adjusted OR of the CBPI did not differ from the crude OR. Owner-perceived pain behavior was not confounded by the dogs' medication. Results indicated that CBPI was not mediated by the medication. The CBPI pain interference score was not associated with response bias and may be used as clinical outcome measure of chronic pain and pain-related disability in dogs with OA along a period of physical rehabilitation comprising pharmacologic and nonpharmacologic pain interventions.

The effectiveness of marine based fatty acid compound (PCSO-524) and firocoxib in the treatment of canine osteoarthritis

Background

NSAIDs are accepted as the most predictably efficacious medical treatment of the clinical signs of osteoarthritis (OA). The marine-based fatty-acid compound PCSO-524 has been proposed as an adjunctive treatment for canine OA, however benefits of this agent is still controversial. The purpose of this study was to evaluate and compare the effectiveness of PCSO-524 combined with the NSAID firocoxib using force plate gait analysis, orthopedic assessment score (OAS) and canine brief pain inventory score (CBPI) in dogs with OA.

A prospective, randomized, double-blinded study was conducted. Seventy-nine dogs that had hip and/or stifle OA were assigned randomly into three treatment groups: firocoxib, PCSO-524 and combination of firocoxib and PCSO-524, orally for 4 weeks. Peak vertical force (PVF, expressed as a percentage of bodyweight), OAS, CBPI, serum prostaglandin E₂ concentration, hematology and blood chemistry values were evaluated before treatment (Day0), as well as at the second (Day14) and fourth week (Day28) during treatment.

Results

Within group analysis revealed significant increases in PVF over the 4-week treatment period for firocoxib, PCSO-524 and the combination (p < 0.05). Mean increases in PVF were 3.25 ± 4.13, 2.01 ± 3.86, 4.11 ± 4.69%BW (mean ± SD) respectively. The OAS showed non-significant change in all treatment groups. There were significant decreases in CBPI pain severity score (PSS) and CBPI pain interference scores (PIS) within some groups over time, however no significant differences were found between the groups. Significantly decreased serum PGE₂ concentration (p < 0.05) was found in the combination group. Significant increases in BUN and creatinine (p < 0.05) compared to pre-treatment values were found in the firocoxib and combination groups but not in the PCSO-524 group at day28, but all values in all dogs remained within the normal ranges.

Conclusions

The results of this study suggested combination of both PCSO-524 and firocoxib is more effective in alleviation of inflammation and improvement of weight bearing ability when compared to the uses of either PCSO-524 or firocoxib alone. Further clinical studies are needed to confirm this, and to determine if there is any benefit of PCSO-524 over placebo.

Successful Treatment of Pneumothorax in a Dog With Sterile Pleural Fibrosis Caused by Chylothorax

A 2-year-old, 12 kg, intact male crossbreed dog was presented with respiratory distress, exercise intolerance, and gagging. Plain thoracic radiographs revealed severe pleural effusion. Although bilateral needle thoracocentesis and chest tube placement were performed, no re-expansion of the lung lobes occurred. Pleural effusion was of chylous quality and led to lung entrapment. Computer tomography revealed a highly atrophic and atelectatic right middle lung lobe. The remaining lung lobes were only expanded to ~40%. Visceral pleura and pericardium showed a heterogeneous thickening consistent with pleural fibrosis. Partial pericardiectomy with resection of the middle lung lobe through a right lateral thoracotomy was performed. Ligation of the thoracic duct and ablation of the cisterna chyli was achieved through a single paracostal approach. Histopathology revealed chronic-active proliferative beginning granulomatous pleuritis, fibrotic pericarditis, and partial coagulative necrosis with incomplete granulomatous sequestration in the resected middle lung lobe. Chylothorax resolved after surgical intervention. Active pleural effusion resolved, and lung entrapment changed to trapped lung disease. The remaining lung lobes re-expanded to ~80% over the following 6 days. The dog was discharged 10 days later. Mild to moderate pleural effusion of non-chylic quality was present during the following 4 months. Meloxicam was administered for 4 months because of its anti-fibrotic and anti-inflammatory properties. Fifteen months later, thoracic radiographs revealed full radiologic expansion of the lungs with persistent mild pleural fibrosis. To the authors' knowledge, this is the first case report of pneumothorax due pleural fibrosis caused by chylothorax in a dog with an excellent clinical outcome.

Measurement of chronic pain in companion animals: Discussions from the Pain in Animals Workshop (PAW) 2017

In the face of increasing recognition and interest in treating chronic pain in companion animals, we struggle with a lack of therapeutic options. A significant barrier to the development of new therapeutics, or the critical evaluation of current therapies, is our inability to accurately measure chronic pain and its impact on companion animals. Over the last 20 years, much progress has been made in developing methods to measure chronic pain via subjective and objective methods - particularly in owner assessment tools and measurements of limb use and activity. Most work has been focused on chronic joint pain conditions, but there has been relatively little work in other areas of chronic pain, such as neuropathic and cancer pain. Although progress has been made, there is a considerable interest in improving our assessment of chronic pain, as evidenced by the multiple disciplines across industry, academia, and clinical practice from the veterinary and human medical fields that participated in the Pain in Animals Workshop held at the National Institutes of Health in 2017. This review is one product of that meeting and summarizes the current state of knowledge surrounding the measurement of chronic pain (musculoskeletal, cancer, neuropathic), and its impact, in cats and dogs.

Safety and efficacy of reduced dosage ketoprofen with or without tramadol for long-term treatment of osteoarthritis in dogs: a randomized clinical trial

BACKGROUND

This study aimed to evaluate the safety and efficacy of reduced-dosage ketoprofen with or without tramadol in dogs. Five healthy dogs receiving standard-dosage ketoprofen (2 mg/kg SC, then 1 mg/kg PO daily) comprised Group A. Twenty dogs with osteoarthritis were randomized to receive reduced-dosage ketoprofen (0.5 mg/kg SC once; 0.25 mg/kg PO daily) alone (Group B) or in combination with tramadol (5 mg/kg/day PO) (Group C). Treatments were administered for 28 days. Platelet aggregation time (PAT), gastrointestinal (GI) endoscopy and glomerular filtration rate (GFR) were performed up to 60 days after treatment initiation. Pain was scored using a validated clinical metrology instrument up to D120. Data were analyzed with general linear mixed model for repeated measures (α = 0.05).

RESULTS

PAT was not different between groups but was increased with time for all groups. GI lesion scores were higher in Group A than Groups B and C (day 28; P = 0.005) and were increased with time for Group A (P = 0.005). GFR was lower in Group A than Groups B and C (day 28; P < 0.01) and were decreased with time for group A (P < 0.001). Standard-dosage ketoprofen administration resulted in clinically relevant adverse effects. Pain score decreased in both treated groups (B and C) from D0 to D28. Need of rescue analgesia from D29 to D120 was higher in Group B than in Group C (P = 0.039).

CONCLUSIONS

The long-term safety profile of reduced-dosage ketoprofen is similar whether the drug is administered alone or in combination with tramadol to dogs with osteoarthritis. Analgesic efficacy of the combination looks attractive.

Effects of low-level laser therapy on bone healing and signs of pain in dogs following tibial plateau leveling osteotomy

OBJECTIVE To assess the effect of low-level laser therapy (LLLT) on markers of synovial inflammation and signs of pain, function, bone healing, and osteoarthritis following tibial plateau leveling osteotomy (TPLO) in dogs with spontaneous cranial cruciate ligament rupture (CCLR). ANIMALS 12 client-owned dogs with unilateral CCLR. PROCEDURES All dogs were instrumented with an accelerometer for 2 weeks before and 8 weeks after TPLO. Dogs were randomly assigned to receive LLLT (radiant exposure, 1.5 to 2.25 J/cm²; n = 6) or a control (red light; 6) treatment immediately before and at predetermined times for 8 weeks after TPLO. Owners completed a Canine Brief Pain Inventory weekly for 8 weeks after surgery. Each dog underwent a recheck appointment, which included physical and orthopedic examinations, force plate analysis, radiography and synoviocentesis of the affected joint, and evaluation of lameness and signs of pain, at 2, 4, and 8 weeks after surgery. Select markers of inflammation were quantified in synovial fluid samples. Variables were compared between the 2 groups. RESULTS For the control group, mean ground reaction forces were greater at 2 and 4 weeks after TPLO and owner-assigned pain scores were lower during weeks 1 through 5 after TPLO, compared with corresponding values for the LLLT group. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the LLLT protocol used had no beneficial effects on signs of pain or pelvic limb function following TPLO. Further research is necessary to evaluate the effects of LLLT and to determine the optimum LLLT protocol for dogs with CCLR.

Evaluation of the effect of signalment and owner-reported impairment level on accelerometer-measured changes in activity in osteoarthritic dogs receiving a non-steroidal anti-inflammatory

In veterinary medicine, evaluation of osteoarthritis (OA) treatment efficacy remains challenging. Measurement of activity, utilizing accelerometers, provides a surrogate measure of pain through measuring effects on activity, and the objective data collected can be used to assess the efficacy of treatments. However, little is known about how dog characteristics impact the accelerometry-measured response to treatment. The objectives of this study were to evaluate the effect of signalment and initial impairment level on accelerometer-measured changes in activity in osteoarthritic dogs after receiving a non-steroidal anti-inflammatory (NSAID). Fifty-seven client-owned dogs with OA-associated pain and mobility impairment were administered meloxicam for 2 weeks, following a 2-week baseline, and spontaneous activity was measured using an Actical accelerometer unit. Signalment factors and disease variables were recorded (age, sex, weight, impairment level, forelimb or hindlimb pain). Initial degree of impairment had a significant effect on changes in weekly (P=0.009), weekday (P=0.044) activity following NSAID treatment. Greater initial impairment was associated with larger positive changes in activity. Degree of impairment should be taken into consideration during the development of a clinical trial. Appropriate selection of candidates based on initial degree of impairment may permit a greater treatment effect, therefore increasing the power of the study.

Initial evaluation of PetPace activity monitor

Mobility is considered a vital component of health and quality of life in humans and companion animals. Wearable devices for pets that can monitor activity and other aspects of health are increasingly being marketed to veterinarians and owners, with claims around their ability to monitor aspects of health. However, there is little scientific evidence to support the validity of these claims. To address this, the objective of this study was to assess the correlation of the activity measurement from the PetPace device compared to activity output from Actigraph and the validated Actical device. Ten client-owned, healthy dogs were used for the study. The three devices were mounted simultaneously on a dedicated collar and activity was recorded during a period of 7 days. There were moderate correlations between the Actical and the PetPace (r²=0.59, P=<0.001). There was high correlation between the PetPace and the Actigraph (r²=0.85, P=<0.001) and between the Actical and the Actigraph (r²=0.72, P=<0.001). If the Actical activity counts were limited under 50,000 per hour, there was strong correlation between the Actical and the PetPace (r²=0.71, P=<0.001) and between the Actical and the Actigraph (r²=0.86, P=<0.001). PetPace has a moderate correlation with the most validated activity monitor that has been used in veterinary medicine. Its real-time data acquisition, user friendly interface for owners and cost make this device an attractive tool for monitoring activity in dogs. Further studies maybe needed to evaluate its performance, validity and clinical utility in the field.

Spontaneous painful disease in companion animals can facilitate the development of chronic pain therapies for humans

OBJECTIVE

To outline the role that spontaneous osteoarthritis (OA) in companion animals can play in translational research and therapeutic pharmacological development.

OUTLINE

Narrative review summarizing the opportunities and limitations of naturally occurring, spontaneous OA as models of human OA pain, with a focus on companion animal pets. The background leading to considering inserting spontaneous disease models in the translational paradigm is provided. The utility of this model is discussed in terms of outcome measures that have been validated as being related to pain, and in terms of the potential for target discovery is outlined. The limitations to using companion animal pets as models of human disease are discussed.

CONCLUSIONS

Although many steps along the translational drug development pathway have been identified as needing improvement, spontaneous painful OA in companion animals offers translational potential. Such 'models' may better reflect the complex genetic, environmental, temporal and physiological influences present in humans and current data suggests the predictive validity of the models are good. The opportunity for target discovery exists but is, as yet, unproven.

Assessment of agreement among diplomates of the American College of Veterinary Anesthesia and Analgesia for scoring the recovery of horses from anesthesia by use of subjective grading scales and development of a system for evaluation of the recovery of horses from anesthesia by use of accelerometry

OBJECTIVE To evaluate agreement among diplomates of the American College of Veterinary Anesthesia and Analgesia for scores determined by use of a simple descriptive scale (SDS) or a composite grading scale (CGS) for quality of recovery of horses from anesthesia and to investigate use of 3-axis accelerometry (3AA) for objective evaluation of recovery. ANIMALS 12 healthy adult horses. PROCEDURES Horses were fitted with a 3AA device and then were anesthetized. Eight diplomates evaluated recovery by use of an SDS, and 7 other diplomates evaluated recovery by use of a CGS. Agreement was tested with κ and AC1 statistics for the SDS and an ANOVA for the CGS. A library of mathematical models was used to map 3AA data against CGS scores. RESULTS Agreement among diplomates using the SDS was slight (κ = 0.19; AC1 = 0.22). The CGS scores differed significantly among diplomates. Best fit of 3AA data against CGS scores yielded the following equation: RS = 9.998 × SG^0.633 × ∑UG^0.174, where RS is a horse's recovery score determined with 3AA, SG is acceleration of the successful attempt to stand, and ∑UG is the sum of accelerations of unsuccessful attempts to stand. CONCLUSIONS AND CLINICAL RELEVANCE Subjective scoring of recovery of horses from anesthesia resulted in poor agreement among diplomates. Subjective scoring may lead to differences in conclusions about recovery quality; thus, there is a need for an objective scoring method. The 3AA system removed subjective bias in evaluations of recovery of horses and warrants further study.

Psychometric evaluation of the canine brief pain inventory in a Swedish sample of dogs with pain related to osteoarthritis

BACKGROUND

To evaluate intervention, implement evidence-based practice and enhance the welfare of dogs with naturally occurring osteoarthritis (OA), access to valid, reliable and clinically relevant outcome measures is crucial for researchers, veterinarians and rehabilitation practitioners. The objectives of the present study were to translate and evaluate psychometric properties, in terms of internal consistency and construct validity, of the owner-reported measure canine brief pain inventory (CBPI) in a Swedish sample of dogs with pain related to OA.

RESULTS

Twenty-one owners of clinically sound dogs and 58 owners of dogs with pain related to OA were included in this observational and cross-sectional study. After being translated according to the guidelines for patient-reported outcome measures, the CBPI was completed by the canine owners. Construct validity was assessed by confirmatory factor analysis, by repeating the principal component analysis and by assessing for differences between clinically sound dogs and dogs with pain related to OA. Internal consistency was estimated by Cronbach's α. Confirmatory factor analysis was not able to confirm the factor-structure models tested in our sample. Principal component analysis showed a two-component structure, pain severity and pain interference of function. Two components accounted for 76.8% of the total variance, suggesting an acceptable fit of a two-component structure. The ratings from the clinically sound dogs differed from OA dogs and showed significantly lower CBPI total sum. Cronbach's α was 0.94 for the total CBPI, 0.91 for the pain severity and 0.91 for the pain interference of function.

CONCLUSIONS

The results indicate that the translated version of the CBPI is valid for use in the Swedish language. The findings suggest satisfying psychometric properties in terms of high internal consistencies and ability to discriminate clinically sound dogs from OA dogs. However, based on the confirmatory factor analysis, the original factor structure in the CBPI is not ideally suited to measure pain related to OA in our sample and the hypothesis of the presented two-factor structure was rejected. Further research needs to be conducted to determine whether the original psychometric results from CBPI can be replicated across different target groups and particularly with larger sample size.

Anti-nerve growth factor therapy increases spontaneous day/night activity in mice with orthopedic surgery-induced pain

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are 2 of the most common and successful surgical interventions to relieve osteoarthritis pain. Control of postoperative pain is critical for patients to fully participate in the required physical therapy which is the most influential factor in effective postoperative knee rehabilitation. Currently, opiates are a mainstay for managing postoperative orthopedic surgery pain including TKA or THA pain. Recently, issues including efficacy, dependence, overdose, and death from opiates have made clinicians and researchers more critical of use of opioids for treating nonmalignant skeletal pain. In the present report, a nonopiate therapy using a monoclonal antibody raised against nerve growth factor (anti-NGF) was assessed for its ability to increase the spontaneous activity of the operated knee joint in a mouse model of orthopedic surgery pain-induced by drilling and coring the trochlear groove of the mouse femur. Horizontal activity and velocity and vertical rearing were continually assessed over a 20 hours day/night period using automated activity boxes in an effort to reduce observer bias and capture night activity when the mice are most active. At days 1 and 3, after orthopedic surgery, there was a marked reduction in spontaneous activity and vertical rearing; anti-NGF significantly attenuated this decline. The present data suggest that anti-NGF improves limb use in a rodent model of joint/orthopedic surgery and as such anti-NGF may be useful in controlling pain after orthopedic surgeries such as TKA or THA.

Widespread somatosensory sensitivity in naturally occurring canine model of osteoarthritis

Osteoarthritis (OA)-associated pain is a leading cause of disability. Central sensitization (CS), as a result of OA, is recognized as an important facet of human patients' chronic pain and has been measured in people using quantitative sensory testing (QST) testing. The spontaneous canine OA model has been suggested as a good translational model, but CS has not been explored in this model. In this study, QST was performed on dogs with and without spontaneous hip or stifle OA to determine whether OA is associated with CS in this model. Mechanical (von Frey and blunt pressure) and thermal (hot and cold) sensory thresholds obtained in dogs with chronic OA-associated pain (n = 31) were compared with those of normal dogs (n = 23). Dogs were phenotyped and joint-pain scored, and testing was performed at the OA-affected joint, cranial tibial muscle, and dorsal metatarsal region. QST summary data were evaluated using mixed-effect models to understand the influence of OA status and covariates, and dogs with OA and control dogs were compared. The presence of OA was strongly associated with hyperalgesia across all QST modalities at the index joint, cranial tibial muscle, and metatarsal site. Mechanical QST scores were significantly moderately negatively correlated with total joint-pain scores. The spontaneous canine OA model is associated with somatosensory sensitivity, likely indicative of CS. These data further validate the canine spontaneous OA model as an appropriate model of the human OA pain condition.

The method of attachment influences accelerometer-based activity data in dogs

Background

Accelerometer-based activity monitoring is a promising new tool in veterinary medicine used to objectively assess activity levels in dogs. To date, it is unknown how device orientation, attachment method, and attachment of a leash to the collar holding an accelerometer affect canine activity data. It was our goal to evaluate whether attachment methods of accelerometers affect activity counts. Eight healthy, client-owned dogs were fitted with two identical neck collars to which two identical activity monitors were attached using six different methods of attachment. These methods of attachment evaluated the use of a protective case, positioning of the activity monitor and the tightness of attachment of the accelerometer. Lastly, the effect of leash attachment to the collar was evaluated. For trials where the effect of leash attachment to the collar was not being studied, the leash was attached to a harness. Activity data obtained from separate monitors within a given experiment were compared using Pearson correlation coefficients and across all experiments using the Kruskal-Wallis Test.

Results

There was excellent correlation and low variability between activity monitors on separate collars when the leash was attached to a harness, regardless of their relative positions. There was good correlation when activity monitors were placed on the same collar regardless of orientation. There were poor correlations between activity monitors in three experiments: when the leash was fastened to the collar that held an activity monitor, when one activity monitor was housed in the protective casing, and when one activity monitor was loosely zip-tied to the collar rather than threaded on using the provided metal loop. Follow-up, pair-wise comparisons identified the correlation associated with these three methods of attachment to be statistically different from the level of correlation when monitors were placed on separate collars.

Conclusions

While accelerometer-based activity monitors are useful tools to objectively assess physical activity in dogs, care must be taken when choosing a method to attach the device. The attachment of the activity monitor to the collar should utilize a second, dedicated collar that is not used for leash attachment and the attachment method should remain consistent throughout a study period.

Functional outcome measures in a surgical model of hip osteoarthritis in dogs

Background

The hip is one of the most common sites of osteoarthritis in the body, second only to the knee in prevalence. However, current animal models of hip osteoarthritis have not been assessed using many of the functional outcome measures used in orthopaedics, a characteristic that could increase their utility in the evaluation of therapeutic interventions. The canine hip shares similarities with the human hip, and functional outcome measures are well documented in veterinary medicine, providing a baseline for pre-clinical evaluation of therapeutic strategies for the treatment of hip osteoarthritis. The purpose of this study was to evaluate a surgical model of hip osteoarthritis in a large laboratory animal model and to evaluate functional and end-point outcome measures.

Methods

Seven dogs were subjected to partial surgical debridement of cartilage from one femoral head. Pre- and postoperative pain and functional scores, gait analysis, radiographs, accelerometry, goniometry and limb circumference were evaluated through a 20-week recovery period, followed by histological evaluation of cartilage and synovium.

Results

Animals developed histological and radiographic evidence of osteoarthritis, which was correlated with measurable functional impairment. For example, Mankin scores in operated limbs were positively correlated to radiographic scores but negatively correlated to range of motion, limb circumference and 20-week peak vertical force.

Conclusions

This study demonstrates that multiple relevant functional outcome measures can be used successfully in a large laboratory animal model of hip osteoarthritis. These measures could be used to evaluate relative efficacy of therapeutic interventions relevant to human clinical care.

Electronic supplementary material

The online version of this article (doi:10.1186/s40634-016-0053-5) contains supplementary material, which is available to authorized users.

The attitudes of owners and veterinary professionals in the United Kingdom to the risk of adverse events associated with using non-steroidal anti-inflammatory drugs (NSAIDs) to treat dogs with osteoarthritis

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Many dogs with osteoarthritis receive NSAIDs for long time periods.

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The risk of NSAID-related adverse events concerns veterinary surgeons and dog owners.

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Many strategies are adopted to minimise the risk of these adverse events.

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These strategies may compromise animal welfare through inadequate analgesia.

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The evidence base to support these strategies is inadequate and should be addressed.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed by veterinary surgeons for the treatment of canine osteoarthritis, and affected dogs may receive these drugs for long periods of time. Whilst short term administration of NSAIDs to dogs is linked to adverse events such as gastrointestinal haemorrhage and renal injury, reports of adverse events associated with their long-term administration are limited in the veterinary literature. This study aimed to investigate the attitudes towards the long term use of NSAIDs for canine osteoarthritis held by three groups who manage osteoarthritic dogs in the United Kingdom: dog owners, veterinary surgeons and veterinary nurses. A qualitative methodology was adopted, using semi-structured interviews and focus groups. Thematic analysis of these data identified three themes: awareness of potential risks; recognition of adverse events; and influence of risk perception on the use of NSAIDs. Awareness of, and concern about, the risk of adverse events associated with NSAID administration to dogs with osteoarthritis was high in all groups, with veterinary surgeons being one of a variety of information sources used by owners to acquire this knowledge. Veterinary surgeons described difficulty in recognising, managing and avoiding adverse events associated with NSAIDs. When adverse events occurred, a wide range of management approaches were adopted ranging from a brief drug respite to permanent cessation of administration of any NSAIDs to that dog. Commonly employed approaches to minimise risk included dose reduction and screening blood tests. This study describes a high level of concern about the risks associated with long term NSAID administration to dogs with osteoarthritis and highlights a diverse range of strategies employed to minimise these risks. The evidence base for these strategies is poor, and this may present a risk to animal welfare if the affected dogs are not receiving adequate analgesia. In order to address this, more accurate and comprehensive data must be supplied to both veterinary professionals and owners on the true frequency of adverse events associated with long term administration of veterinary NSAIDs and how best to avoid them.

Quality of life assessment in domestic dogs: An evidence-based rapid review

Assessment of quality of life (QoL) is an important, increasingly popular outcome measure in veterinary research and practice, particularly in dogs. In humans, QoL is commonly assessed by self-reporting and since this is not possible for animals, it is crucial that instruments designed to measure QoL are tested for reliability and validity. Using a systematic, replicable literature search strategy, the aim of this study was to find published, peer-reviewed instruments for QoL assessment in dogs and to assess the quality of these. CAB Abstracts and PubMed were searched in July 2013 using terms relevant to dogs, wellbeing and QoL. Inclusion and exclusion criteria were applied. When instruments were not published in full, authors were contacted to obtain them. Criteria were applied to assess the quality, validity and reliability of the 52 instruments obtained. Twenty-seven additional instruments used in peer-reviewed publications were not included because they had not been fully described in the publication or were not provided by authors upon request. Most of the instruments reviewed (48/52) were disease-specific rather than generic. Only four publications provided a definition of QoL or wellbeing. Only 11/52 instruments demonstrated evidence of assessing reliability or validity, and the quality of these instruments was variable. Many novel, unvalidated instruments have been generated and applied as clinical outcomes before it was known whether they measured QoL. This rapid review can be used to identify currently available and validated canine QoL instruments, and to assess the validity and quality of new or existing instruments.

Criterion Validation Testing of Clinical Metrology Instruments for Measuring Degenerative Joint Disease Associated Mobility Impairment in Cats

Introduction

Degenerative joint disease and associated pain are common in cats, particularly in older cats. There is a need for treatment options, however evaluation of putative therapies is limited by a lack of suitable, validated outcome measures that can be used in the target population of client owned cats. The objectives of this study were to evaluate low-dose daily meloxicam for the treatment of pain associated with degenerative joint disease in cats, and further validate two clinical metrology instruments, the Feline Musculoskeletal Pain Index (FMPI) and the Client Specific Outcome Measures (CSOM).

Methods

Sixty-six client owned cats with degenerative joint disease and owner-reported impairments in mobility were screened and enrolled into a double-masked, placebo-controlled, randomized clinical trial. Following a run-in baseline period, cats were given either placebo or meloxicam for 21 days, then in a masked washout, cats were all given placebo for 21 days. Subsequently, cats were given the opposite treatment, placebo or meloxicam, for 21 days. Cats wore activity monitors throughout the study, owners completed clinical metrology instruments following each period.

Results

Activity counts were increased in cats during treatment with daily meloxicam (p<0.0001) compared to baseline. The FMPI results and activity count data offer concurrent validation for the FMPI, though the relationship between baseline activity counts and FMPI scores at baseline was poor (R²=0.034). The CSOM did not show responsiveness for improvement in this study, and the relationship between baseline activity counts and CSOM scores at baseline was similarly poor (R²=0.042).

Conclusions

Refinements to the FMPI, including abbreviation of the instrument and scoring as percent of possible score are recommended. This study offered further validation of the FMPI as a clinical metrology instrument for use in detecting therapeutic efficacy in cats with degenerative joint disease.

A canine-specific anti-nerve growth factor antibody alleviates pain and improves mobility and function in dogs with degenerative joint disease-associated pain

Background

There is a critical need for proven drugs other than non-steroidal anti-inflammatory drugs for treatment of degenerative joint disease (DJD) pain in dogs. Antibodies against nerve growth factor (NGF) are analgesic in rodent models and in humans with DJD. This pilot study aimed to evaluate the efficacy of a novel caninised anti-NGF antibody (NV-01) for the treatment of DJD pain in dogs. In a randomized, parallel group, stratified, double masked, placebo controlled, proof of principle clinical pilot study design, 26 dogs with DJD received NV-01 (200 mcg/kg IV) or placebo on day 0 (D0). In addition to objective accelerometry measures, owners completed clinical metrology instruments (Client-Specific Outcome Measures [CSOM], Canine Brief Pain Inventory [CBPI] and Liverpool Osteoarthritis in Dogs Index [LOAD]) on D0, D14 and D28. CBPI subscales (pain severity [PS] and pain interference [PI]), CSOM and LOAD scores were evaluated within and between groups for change over time. Recognized success/failure criteria were applied and success compared between groups.

Results

CBPI PS and PI scores significantly improved in the NV-01 group (PS: D0-14, P = 0.012 and D0-28, P = 0.019; PI: D0-14, P = 0.012 and D0-28, P = 0.032) but not in the placebo group. CSOM scores showed similar patterns with a significant difference between within-group changes at D14 and D28 (P = 0.038 and P = 0.009, respectively), and significantly more successes at D28 (P = 0.047). LOAD scores significantly improved in the NV-01 group (D0-14, P = 0.004 and D0-28, P = 0.002) but not in the placebo group. There were significant differences between the groups for change in LOAD score at D14 (P = 0.014) and D28 (P = 0.033). No side effects were noted. Activity in the NV-01 group increased over the study period compared to placebo (P = 0.063) and the difference between the groups for change in activity over the time period 9am-5pm (8 hours) was significant (P = 0.006).

Conclusions

These pilot data demonstrate a positive analgesic effect of anti-NGF antibody in dogs suffering from chronic pain. The magnitude of the effect appeared identical to that expected with an NSAID.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0413-x) contains supplementary material, which is available to authorized users.

Global positioning system derived performance measures are responsive indicators of physical activity, disease and the success of clinical treatments in domestic dogs

Objective

To assess the use of Global Positioning System receiver (GPS) derived performance measures for differentiating between: 1) different outdoor activities in healthy dogs; 2) healthy dogs and those with osteoarthritis; 3) osteoarthritic dogs before and after treatment with non-steroidal anti-inflammatory analgesia.

Design

Prospective study.

Animals

Ten healthy dogs and seven dogs with osteoarthritis of the elbow joint (OA dogs).

Procedure

Healthy dogs were walked on a standard route on-lead, off-lead and subjected to playing activity (chasing a ball) whilst wearing a GPS collar. Each dog was walked for five consecutive days. Dogs with OA were subjected to a single off-lead walk whilst wearing a GPS collar, and then administered oral Carprofen analgesia daily for two weeks. OA dogs were then subjected to the same walk, again wearing a GPS collar.

Results

GPS derived measures of physical performance could differentiate between on-lead activity, off-lead activity and playing activity in healthy dogs, and between healthy dogs and OA dogs. Variation in the performance measures analysed was greater between individual dogs than for individual dogs on different days. Performance measures could differentiate healthy dogs from OA dogs. OA Dogs treated with Carprofen analgesia showed improvements in their physical performance, which returned to values indistinguishable from those of healthy dogs on nearly all the measures assessed.

Conclusions and Clinical Relevance

GPS derived measures of physical performance in dogs are objective, easy to quantify, and can be used to gauge the effects of disease and success of clinical treatments. Specific stimuli can be used to modulate physical performance beyond the self-governed boundaries that dogs will naturally express when allowed to exercise freely without stimulation.

Initial evaluation of nighttime restlessness in a naturally occurring canine model of osteoarthritis pain

Chronic pain due to osteoarthritis (OA) can lead to significant disruption of sleep and increased restlessness. Our objective was to assess whether naturally occurring canine OA is associated with nighttime restlessness and so has potential as a model of OA-associated sleep disturbance. The study was designed as a two-part prospective masked, placebo-controlled study using client-owned dogs (Part A n = 60; Part B n = 19). Inclusion criteria consisted of OA-associated joint pain and mobility impairment. The primary outcome measure for both parts was nighttime accelerometry. In Part B, quality of sleep was assessed using a clinical metrology instrument (Sleep and Night Time Restlessness Evaluation Score, SNoRE). Part A included dogs receiving two weeks of non-steroidal anti-inflammatory drug (NSAID) preceded with two weeks of no treatment. Part B was a crossover study, with NSAID/placebo administered for two weeks followed by a washout period of one week and another two weeks of NSAID/placebo. Repeated measures analysis of variance was used to assess differences between baseline and treatment. There were no significant changes in accelerometry-measured nighttime activity as a result of NSAID administration. SNoRE measures indicated significant improvements in aspects of the quality of nighttime sleep that did not involve obvious movement. These results reflect the few similar studies in human OA patients. Although accelerometry does not appear to be useful, this model has potential to model the human pain-related nighttime sleep disturbance, and other outcome measures should be explored in this model.

Improving the translation of analgesic drugs to the clinic: animal models of neuropathic pain

Neuropathic pain remains an area of considerable unmet clinical need. Research based on preclinical animal models has failed to deliver truly novel treatment options, questioning the predictive value of these models. This review addresses the shortcomings of rodent in vivo models commonly used in the field and highlights approaches which could increase their predictivity, including more clinically relevant assays, outcome measures and animal characteristics. The methodological quality of animal studies also needs to be improved. Low internal validity and incomplete reporting lead to a waste of valuable research resources and animal lives, and ultimately prevent an objective assessment of the true predictivity of in vivo models.

Mavacoxib and meloxicam for canine osteoarthritis: a randomised clinical comparator trial

NSAIDs are the cornerstone of medical management of canine osteoarthritis (OA). Meloxicam is a daily-administered NSAID widely available in a liquid formulation and manufacturer's summary of product characteristics (SPC) advise that it is given at the lowest effective dose. Mavacoxib is a long-acting NSAID given as a monthly tablet. This study compares these drugs in the management of canine OA. In all, 111 dogs with OA of the elbow, hip or stifle were randomly assigned to receive one of these NSAIDs for a 12-week period, and to administer them as per the manufacturer's SPC. Outcomes, including ground reaction forces and three validated clinical metrology instruments, were measured at baseline, 6 and 12 weeks. Improvements were seen in all outcome measures for both groups to a similar degree, and adverse events occurred at a similar rate. There were significant improvements in outcome measures from week 6 to week 12, as well as from baseline. Long-term meloxicam dose was more important than recent dose. Clinical efficacy and adverse event rates are similar for meloxicam and mavacoxib when administered as per their UK SPC. This is relevant information for veterinary surgeons when prescribing NSAID treatment for canine OA.

A fully caninised anti-NGF monoclonal antibody for pain relief in dogs

Background

Monoclonal antibodies are a major class of biological therapies in human medicine but have not yet been successfully applied to veterinary species. We have developed a novel approach, PETisation, to rapidly convert antibodies for use in veterinary species. As an example, anti-nerve growth factor (anti-NGF) monoclonal antibodies (mAbs) which are effective in reducing acute and chronic pain in rodents and man are potentially useful for treating pain in dogs but a fully caninised mAb is required in order to avoid an immune response. The aim of this study was to determine the optimal properties of a caninised anti-NGF mAb for safe, repeated administration to dogs, to determine its pharmacokinetic properties and to evaluate its efficacy in a model of inflammatory pain in vivo.

Results

Starting with a rat anti-NGF mAb, we used a novel algorithm based on expressed canine immunoglobulin sequences to design and characterise recombinant caninised anti-NGF mAbs. Construction with only 2 of the 4 canine IgG heavy chain isotypes (A and D) resulted in stable antibodies which bound and inhibited NGF with high-affinity and potency but did not bind complement C1q or the high-affinity Fc receptor gamma R1 (CD64). One of the mAbs (NV-01) was selected for scale-up manufacture, purification and pre-clinical evaluation. When administered to dogs, NV-01 was well tolerated, had a long serum half-life of 9 days, was not overtly immunogenic following repeated dosing in the dog and reduced signs of lameness in a kaolin model of inflammatory pain.

Conclusions

The combination of stability, high affinity and potency, no effector activity and long half-life, combined with safety and activity in the model of inflammatory pain in vivo suggests that further development of the caninised anti-NGF mAb NV-01 as a therapeutic agent for the treatment of chronic pain in dogs is warranted.

Systematic review of nonsteroidal anti-inflammatory drug-induced adverse effects in dogs

The aim of this systematic review was to identify, assess, and critically evaluate the quality of evidence of nonsteroidal anti-inflammatory drug (NSAID)-induced adverse effects in dogs. Original prospective studies published in peer-reviewed journals in English (1990-2012) that reported data on the safety of NSAIDs administration in dogs were searched. For each study, design type (I, II, III, or IV) and assessment of quality (+, Ø, -) were rated. For each drug, quantity and consistency rating (***, **, *) and strength of evidence (high, moderate, low, or extremely low) were identified and evaluated. The strength of evidence was defined in terms of how applicable and relevant the conclusions were to the target population. Sixty-four studies met the inclusion criteria. Thirty-five (55%) research studies and 29 (45%) clinical trials were identified. A high strength of evidence existed for carprofen, firocoxib, and meloxicam; moderate for deracoxib, ketoprofen, and robenacoxib; and low for etodolac. Quality and consistency rating were as follows: carprofen (***/***), deracoxib (**/***), etodolac (*/unable to rate), firocoxib (***/**), ketoprofen (**/***), meloxicam (***/***), and robenacoxib (**/**), respectively. Adverse effects were detected in 35 studies (55%) and commonly included vomiting, diarrhea, and anorexia. Three studies (5%) reported a power analysis related to adverse effects of ≥80%. In randomized, placebo-controlled, blinded studies (n = 25, 39%), the incidence of adverse effects was not statistically different between treated and control dogs. Finally, most studies were not appropriately designed to determine the safety of NSAIDs, and involved a healthy nongeriatric population of research dogs.

Evaluation of construct and criterion validity for the 'Liverpool Osteoarthritis in Dogs' (LOAD) clinical metrology instrument and comparison to two other instruments

Objective

To test the ‘Liverpool Osteoarthritis in Dogs’ (LOAD) questionnaire for construct and criterion validity, and to similarly test the Helsinki Chronic Pain Index (HCPI) and the Canine Brief Pain Inventory (CBPI).

Design

Prospective Study.

Animals

222 dogs with osteoarthritis.

Procedure

Osteoarthritis was diagnosed in a cohort of dogs on the basis of clinical history and orthopedic examination. Force-platform analysis was performed and a “symmetry index” for peak vertical force (PVF) was calculated. Owners completed LOAD, CBPI and HCPI instruments. As a test of construct validity, inter-instrument correlations were calculated. As a test of criterion validity, the correlations between instrument scores and PVF symmetry scores were calculated. Additionally, internal consistency of all instruments was calculated and compared to those previously reported. Factor analysis is reported for the first time for LOAD, and is compared to that previously reported for CBPI and HCPI.

Results

Significant moderate correlations were found between all instruments, implying construct validity for all instruments. Significant weak correlations were found between LOAD scores and PVF symmetry index, and between CBPI scores and PVF symmetry index.

Conclusion and Clinical Relevance

LOAD is an owner-completed clinical metrology instrument that can be recommended for the measurement of canine osteoarthritis. It is convenient to use, validated and, as demonstrated here for the first time, has a correlation with force-platform data.

The challenges of assessing osteoarthritis and postoperative pain in dogs

The challenge of measuring pain in veterinary medicine is compounded by the lack of fully validated, reliable methods to measure and assess pain in nonverbal patients. In human medicine, there are numerous, validated pain assessment tools (PATs) for assessing various, specific types of pain. The advances in human medicine pain management and numerous validated pain scales should serve as incentives and templates to facilitate similar advances in the development of validated PATs for use in dogs (and other species). The limited number of canine PATs constrains our ability to adequately and reliably assess pain. Improving the ability to quantify osteoarthritis and postoperative pain in dogs would enhance the development of analgesics for animals, advance the management of animal pain, facilitate the use of animal pain models in preclinical trials for human analgesics, and provide insight into the quantification of pain responses in humans who lack the ability to adequately communicate. This review describes the need for practical, valid, and reliable PATs for use in veterinary patients and discusses some currently available PATs commonly used to evaluate acute and chronic pain in dogs.

Owner-assessed indices of quality of life in cats and the relationship to the presence of degenerative joint disease

This study evaluated the types of items owners consider important to their cats' quality of life (QoL). We hypothesized that items contributing to QoL in cats are predominantly items requiring mobility. The objectives of the study were to describe the types of items considered important by owners for their cats' QoL; to describe the proportion of these items that involve mobility; to evaluate what patient factors, including severity of degenerative joint disease (DJD), affect this distribution; and to evaluate whether the proportion of QoL items involving mobility chosen by owners is different in cats presenting for a DJD study compared with a randomly selected population. A total of 830 client-generated items were evaluated. Regardless of DJD status, 40% of items listed by owners involved mobility, while 60% were 'inactive' items, rejecting our hypothesis. This highlights the need to assess non-active items that owners consider to constitute QoL to fully assess the impact of diseases like DJD and, therefore, the success of therapeutic interventions.

An un-commissioned randomized, placebo-controlled double-blind study to test the effect of deep sea fish oil as a pain reliever for dogs suffering from canine OA

BACKGROUND

An un-commissioned randomized, double-blinded, placebo controlled clinical study was planned using a deep sea fish oil product for pets. Seventy-seven client-owned dogs with osteoarthritis were randomly assigned to supplement the food with either the fish oil product or corn (=placebo) oil. Our main outcome variables were force platform variables peak vertical force (PVF) and impulse, the validated Helsinki Chronic Pain Index (HCPI) and the use of rescue NSAIDs. Secondary outcome variables were a locomotion visual analog scale (VAS), a Quality of life VAS, a comparative questionnaire, a veterinary assessment, owners' final assessment of outcome and guessing the product given.

RESULTS

When comparing the two test groups at the end of the trial (16 weeks) there was no significant difference in any of the main outcome variables but owners of dogs that had taken fish oil were significantly happier with the treatment at the end visit and did significantly better at guessing what group their dogs had been in, compared to the placebo group. When comparing variables within the fish oil group as change from baseline to trial end, there were significant positive changes in PVF, HCPI, NSAID use, Quality of life VAS, as well as in all three scores in the comparative questionnaire (locomotion, every-day situations, and skin & coat). There were similar positive trends in force platform impulse and in the veterinary assessment variables, although they did not reach significance. Within the placebo group there were significant positive changes only in the HCPI and a significant deterioration according to veterinary assessment.

CONCLUSIONS

When compared to placebo, there was not a major statistically significant benefit in using deep sea fish oil as a pain reliever in our study population of dogs suffering from osteoarthritis. However, the fish oil treated patients improved significantly in many of the variables, when comparing baseline values to the study-end values within the group, indicating a true but small relief in symptoms. Deep sea fish oil supplementation could be considered a part of the multimodal pain relieving approach currently recommended for dogs suffering from OA, especially for individuals that do not tolerate anti-inflammatory drugs.