(a) Plasma buprenorphine concentrations measured in 33 cats after subcutaneous (SC) injection of buprenorphine 0.02 mg/kg (AG6, orange, n = 3), 0.06 mg/kg (AG4, pink, n = 6), 0.12 mg/kg (AGs 2, 7 and 3, purple, n = 18) and 0.24 mg/kg (AG5, black, n = 6). Injection at time 0. (b) Plasma buprenorphine concentrations corrected to a standard 0.12 mg/kg dose measured in 33 cats after SC injection of buprenorphine 0.02 mg/kg (AG6, orange, n = 3), 0.06 mg/kg (AG4, pink, n = 6), 0.12 mg/kg (AGs 2, 7 and 3, purple, n = 18), 0.24 mg/kg (AG5, black, n = 6). Injection at time 0. NoP = no preservative;+P = with preservatives