Refinement of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians: detection of naturally occurring osteoarthritis in laboratory cats.

Objectives Feline osteoarthritis causes pain and disability. Detection and measurement is challenging, relying heavily on owner report. This study describes refinement of the Montreal Instrument for Cat Arthritis Testing, for Use by Veterinarians. Methods A video analysis of osteoarthritic (n = 6) and non-osteoarthritic (n = 4) cats facilitated expansion of scale items. Three successive therapeutic trials (using gabapentin, tramadol and oral transmucosal meloxicam spray) in laboratory cats with and without natural osteoarthritis (n = 12-20) permitted construct validation (assessments of disease status sensitivity and therapeutic responsiveness) and further scale refinements based on performance. Results Scale osteoarthritic sensitivity improved from phase I to phase III; phase III scale total score ( P = 0.0001) and 4/5 subcategories - body posture ( P = 0.0006), gait ( P = 0.0031), jumping (0.0824) and global distance examination ( P = 0.0001) - detected osteoarthritic cats. Total score inter-rater (intra-class correlation coefficients [ICC] = 0.64-0.75), intra-rater (ICC = 0.90-0.91) and overall internal consistency (Cronbach's alpha = 0.85) reliability were good to excellent. von Frey anesthesiometer-induced paw withdrawal threshold increased with gabapentin in phase I, in osteoarthritic cats ( P <0.001) but not in non-osteoarthritic cats ( P = 0.075). Night-time activity increased during gabapentin treatment. Objective measures also detected tramadol and/or meloxicam treatment effects in osteoarthritic cats in phases II and III. There was some treatment responsiveness: in phase I, 3/10 subcategory scores improved ( P <0.09) in treated osteoarthritic cats; in phase II, 3/8 subcategories improved; and in phase III, 1/5 subcategories improved ( P <0.096). Conclusions and relevance The revised scale detected naturally occurring osteoarthritis, but not treatment effects, in laboratory cats, suggesting future potential for screening of at-risk cats. Further study is needed to confirm reliability, validity (disease sensitivity and treatment responsiveness) and clinical feasibility, as well as cut-off scores for osteoarthritic vs non-osteoarthritic status, in client-owned cats.

Analgesic efficacy of an oral transmucosal spray formulation of meloxicam alone or in combination with tramadol in cats with naturally occurring osteoarthritis.

OBJECTIVE: To evaluate the analgesic efficacy of meloxicam oral transmucosal spray (OTMS) alone and with tramadol in cats with osteoarthritis (OA). STUDY DESIGN: Randomized, blinded study. ANIMALS: Fifteen geriatric cats weighing 4.5 ± 1.0 kg. METHODS: Healthy cats with OA were randomly administered a placebo (every 12 hours orally) and meloxicam OTMS (approximately 0.05 mg kg-1 every 24 hours) (group M, n = 7), or tramadol (3 mg kg-1 every 12 hours orally) and meloxicam OTMS (group TM, n = 8) for 25 days. Evaluations performed before treatment (D0) and at week 3 (W3) consisted of peak vertical force, motor activity and response to mechanical temporal summation of pain (RMTS). Data were analyzed with mixed models and Fisher's exact test. RESULTS: Mean ± standard deviation peak vertical force (percentage of body weight) increased significantly in both groups (p = 0.02), from 47.7 ± 6.5% to 60.5 ± 9.4% in group M, and from 51.8 ± 5.0% to 64.1 ± 6.5% in group TM, with no difference between groups. Motor activity increased in M (from 43 ± 12 to 56 ± 13; p = 0.02), but not in TM. The number of stimulations from RMTS increased in TM only. Cut-off values were reached in a larger number of cats (n = 5) in TM than M (n = 1) (p < 0.05). Gastrointestinal adverse effects were self-limiting in six cats, including five in TM. CONCLUSIONS AND CLINICAL RELEVANCE: Meloxicam OTMS had similar effects on peak vertical force, motor activity and pain sensitization as previously reported for oral meloxicam in OA cats. The tramadol-meloxicam combination provided no evident benefit over meloxicam alone, except for central hypersensitivity (assessed with RMTS). Further assessment of the potential toxicity of the combination is required prior to clinical use. Gingival administration was well accepted overall.