Fifty-five dogs with lymphoma were treated using a doxorubicin-based sequential combination chemotherapy protocol. Complete response, partial response, and no response were seen in 46, 4, and 5 dogs, respectively. The overall median remission duration and survival times were 36 and 51 weeks, respectively. Age, sex, weight, World Health Organization stage, World Health Organization substage (i.e., a = not ill, b = ill), serum calcium concentration, blood urea nitrogen concentration, breed and protocol alteration secondary to toxicity were evaluated for prognostic significance. Univariate analysis of prognostic factors identified sex, World Health Organization substage, and serum calcium as statistically significant (P < or = .05) variables for both survival and remission duration. Upon multivariate analysis, only substage (P = .036) was a significant prognostic factor for remission duration, whereas, both substage (P = .006) and sex (P = .005) were significant prognostic factors for survival.