A randomized, double-blinded, placebo-controlled parallel-group pilot study evaluating the effect of low-dose subcutaneous ketamine as an adjunctive analgesic in dogs with osteoarthritis
Year: 2026
Type: article
Abstract: A randomized, double-blinded, placebo-controlled parallel-group pilot study evaluating the effect of low-dose subcutaneous ketamine as an adjunctive analgesic in dogs with osteoarthritis. Nielsen, M.B.M.a, Thomsen, V.b, Dahl, K.H.a, Hoegh, R.F.a & Poulsen, H.H.a a Department of Veterinary Clinical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Copenhagen, Denmark b University Animal Hospital, Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Uppsala, Sweden Osteoarthritis is a common cause of chronic pain in dogs. Low-dose subcutaneous ketamine is increasingly included in multimodal analgesia, but its efficacy is unproven. Sixteen client-owned dogs with confirmed osteoarthritis were block-randomized to receive either subcutaneous ketamine (0.5 mg kg⁻¹) (Group K) or no treatment (Group P). Ongoing pain management (NSAID, monoclonal antibody, and/or paracetamol) had to be initiated ≥ four weeks prior to enrollment and remained unchanged. Dogs were evaluated before and 7, 14, and 28 days after group allocation by blinded assessors and owners. Clinical metrology assessments included Canine Brief Pain Inventory (CBPI) and clinical gradings (pain and passive range of motion (PROM), Canine OsteoArthritis Staging Tool1). On day 28, owners were asked whether they thought their dog was in group K or P. Wilcoxon Rank Sums and Fisher’s Exact tests were used for non-parametric data and categorial data, respectively, p < 0.05. Dogs with median (range) age 9.5 (6.2–15.2) years and bodyweight 30.1 (12.4–67) kg were enrolled in the study. For group K clinical pain scores decreased from day 0–14 (p = 0.02), and PROM scores decreased from day 0–7 (p = 0.03), and from day 0–14 (p = 0.03), waning over the 28 days. In group P, only significant decrease was in PROM scores day 0-7 (p = 0.03). In group K, CBPI pain interference scores decreased more than in group P, but not significantly, from 3.75 (2.00–5.25) to 2.25 (0.75–4.75) between days 0–7 (p = 0.141). Data showed large visual overlaps between group K and P. However, 12/16 owners correctly identified their dog’s group. Low-dose ketamine additional to ongoing pain treatment in dogs with osteoarthritis points towards a significant effect on pain on manipulation and PROM scores from day 0 to day 14. Further investigation is warranted. References 1. Cachon, T, et al. “Face Validity of a Proposed Tool for Staging Canine Osteoarthritis: Canine OsteoArthritis Staging Tool (COAST).” The Veterinary Journal (1997) [England], vol. 235, May 2018, pp. 1–8, https://doi.org/10.1016/j.tvjl.2018.02.017
Language: English
Subfield: Small Animals
Field: Veterinary
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7164784397