Background: There are no validated systems for measuring pain from osteoarthritis in cats.

Hypothesis: Owner subjective assessments and an activity monitor (AM) can be used to detect pain in cats with osteoarthritis and to assess efficacy of treatments.

Animals: Thirteen cats older than 10 years old, with owner-assessed decreases in activity, painful arthritic joints, and clinically normal blood work were included and evaluated for 3 weeks.

Methods: A collar-mounted AM measured activity and a client-specific outcome measure (CSOM) questionnaire characterized the severity of impairment. Overall global quality of life was also evaluated for each treatment. In weeks 2 and 3, meloxicam (0.1 mg/kg, day 1; 0.05 mg/kg, days 2-5) or a placebo was administered in a blinded, randomized, cross-over manner to test the assessment systems.

Results: The cats had a median of 4 arthritic appendicular joints. Activity counts for the week when cats (complete data on activity; n=9) were administered meloxicam were significantly higher than at baseline (P = .02) but not after placebo (P = .06). Baseline activity counts were not significantly different from placebo (P = .6). The CSOM data (n=13) showed that owners considered their cats to be more active on meloxicam compared with baseline (P = .001) and placebo (P < .004), and more active on placebo than at baseline (P < .01). Global quality of life improved significantly with meloxicam (P < .042).

Conclusions and clinical importance: Both an AM and a CSOM system can detect behavior associated with pain relief in cats that are arthritic. Objective activity data might allow subjective assessment systems to be validated for use in clinical studies.