Ninety-eight dogs with lymphoma treated with a 5-drug combination chemotherapy regimen (vincristine. L-asparaginase. cyclophosphamide. doxorubicin, prednisone [VELCAP-L]) were evaluated for pretreatment characteristics predictive for response and remission duration. The complete remission rate was 6970, with a median remission duration of 55 weeks. Dogs with advanced stage of disease, constitutional signs, dogs that were older, and dogs that were dyspneic were less likely to achieve remission. Once in remission, small dogs and dogs without pretreatment thrombocytopenia were likely to have longer remission duration. Toxicoses were frequent, but rarely fatal. and no predictitive factors were found for a dog developing toxicoses. VELCAP-L is an effective treatment for dogs in stage 1-111 lymphoma, particularly in young, small animals.Key words: Cancer: Remission; Treatment.ymphoma is the most common hematopoietic neo- Although maintenance therapy may be important for duration of remission, it appears that an aggressive induction protocol may also be important in determining both remission rate and duration. The ACOPA-11' protocol had an induction period designed to decrease toxicity and minimize patient visits; this protocol had a low remission rate, possibly due to its decreased dose intensity. The protocol VELCAP-L was designed to provide an intense induction period, followed by a maintenance protocol identical to that used in the ACOPA-I1 protocol (see Fig. 1). Materials and Methods Criteria for Selection of CasesOne hundred eleven dogs with a histologic or cytologic diagnosis of multicentric lymphoma and that had not received prior chemotherapy other than prednisone were eligible for entry into this study. Of these 1 I 1 dogs, 13 were excluded because of poor adherence to protocol or a change in diagnosis (from lymphoma to leukemia). The remaining 98 dogs were treated with the VELCAP-L combination chemotherapy protocol.