@article{williams_meyers_braxton_diekman_lascelles_2022, title={Pilot comparison of outcome measures across chemical and surgical experimental models of chronic osteoarthritis in the rat (Rattus norvegicus)}, volume={17}, ISSN={["1932-6203"]}, url={https://doi.org/10.1371/journal.pone.0277943}, DOI={10.1371/journal.pone.0277943}, abstractNote={Relatively little work has evaluated both the disease of osteoarthritis (OA) and clinically-relevant pain outcome measures across different OA models in rats. The objective of this study was to compare sensitivity, pain, and histological disease severity across chemical and surgical models of OA in the rat. Stifle OA was induced in Sprague–Dawley rats via intraarticular injection of monoiodoacetate (MIA) or surgical transection of anterior cruciate ligament and/or destabilization of medial meniscus (ACL+DMM or DMM alone). Reflexive (e.g., mechanical and thermal stimuli) measures of sensitivity and non-reflexive assays (e.g., lameness, static hindlimb weight-bearing asymmetry, dynamic gait analysis) of pain were measured over time. Joint degeneration was assessed histologically. Six-weeks post OA-induction, the ACL+DMM animals had significantly greater visually observed lameness than MIA animals; however, both ACL+DMM and MIA animals showed equal pain as measured by limb use during ambulation and standing. The MIA animals showed increased thermal, but not mechanical, sensitivity compared to ACL+DMM animals. Joint degeneration was significantly more severe in the MIA model at 6 weeks. Our pilot data suggest both the ACL+DMM and MIA models are equal in terms of clinically relevant pain behaviors, but the MIA model is associated with more severe histological changes over time potentially making it more suitable for screening disease modifying agents. Future work should further characterize each model in terms of complex pain behaviors and biochemical, molecular, and imaging analysis of the sensory system and joint tissues, which will allow for more informed decisions associated with model selection and investigative outcomes.}, number={11}, journal={PLOS ONE}, author={Williams, Morika D. and Meyers, Rachel C. and Braxton, Lauryn A. and Diekman, Brian and Lascelles, B. Duncan X.}, editor={Wijnen, AndreEditor}, year={2022}, month={Nov} } @article{meyers_diener_cohen_2022, title={What Is Your Diagnosis?}, volume={260}, ISSN={["1943-569X"]}, DOI={10.2460/javma.20.11.0632}, abstractNote={HistoryA 6-year-old 16.8-kg spayed female Golden Retriever–Poodle cross was initially seen 5.5 months prior to the time of imaging for excessive licking at the left paw and was treated empirically for allergies and a lick granuloma. The patient was seen again 1 month prior to time of imaging, for a toe-touching, left thoracic limb lameness, and continued licking of the left front paw. On physical examination at that visit, fluctuant swelling was identified on the dorsal aspect of the left metacarpus, which was draining clear serous fluid at the distal margin of the swelling. Strict cage rest for 2}, number={12}, journal={JAVMA-JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Meyers, Rachel C. and Diener, Michelle K. and Cohen, Eli B.}, year={2022}, month={Sep}, pages={1452–1454} } @article{chiu_hash_meyers_lascelles_2020, title={The effect of spontaneous osteoarthritis on conditioned pain modulation in the canine model}, volume={10}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-020-58499-1}, abstractNote={Abstract Endogenous Pain Modulation (EPM) impairment is a significant contributor to chronic pain. Conditioned pain modulation (CPM) testing assesses EPM function. Osteoarthritic (OA) dogs are good translational models, but CPM has not been explored. Our aim was to assess EPM impairment in OA dogs compared to controls using CPM. We hypothesized that CPM testing would demonstrate EPM impairment in OA dogs compared to controls. Dogs with stifle/hip OA and demographically-matched controls were recruited. The pre-conditioning test stimulus, using mechanical/thermal quantitative sensory testing (MQST or TQST), were performed at the metatarsus. A 22N blunt probe (conditioning stimulus) was applied to the contralateral antebrachium for 2 minutes, followed by MQST or TQST (post-conditioning test stimulus). The threshold changes from pre to post-conditioning (∆MQST and ∆TQST) were compared between OA and control dogs. Twenty-four client-owned dogs (OA, n = 11; controls, n = 13) were recruited. The ∆MQST(p < 0.001) and ∆TQST(p < 0.001) increased in control dogs but not OA dogs (∆MQST p = 0.65; ∆TQST p = 0.76). Both ∆MQST(p < 0.001) and ∆TQST(p < 0.001) were different between the OA and control groups. These are the first data showing that EPM impairment is associated with canine OA pain. The spontaneous OA dog model may be used to test drugs that normalize EPM function.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Chiu, King Wa and Hash, Jon and Meyers, Rachel and Lascelles, B. Duncan X.}, year={2020}, month={Feb} } @article{muller_gines_conzemius_meyers_lascelles_2018, title={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}, volume={242}, ISSN={["1532-2971"]}, url={https://dx.doi.org/10.1016/j.tvjl.2018.10.005}, DOI={10.1016/j.tvjl.2018.10.005}, abstractNote={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.}, journal={VETERINARY JOURNAL}, author={Muller, C. and Gines, J. A. and Conzemius, M. and Meyers, R. and Lascelles, B. D. X.}, year={2018}, month={Dec}, pages={48–52} }