Gastrointestinal and hematologic adverse events after administration of vincristine, cyclophosphamide, and doxorubicin in dogs with lymphoma that underwent a combination multidrug chemotherapy protocol.

The present study aimed to objectively evaluate the adverse events after the administration of chemotherapeutic agents used in the University of Wisconsin (UW)-Madison chemotherapy protocol (UW-25) for canine lymphoma, using the Veterinary Co-operative Oncology Group common terminology criteria for adverse events (VCOG-CTCAE). The medical records of 40 dogs with multicentric high-grade lymphoma that underwent UW-25 were reviewed. Gastrointestinal adverse events of grade 2 and above and blood/bone marrow adverse events of all grades were evaluated. Gastrointestinal adverse events occurring at least once during the entire period of UW-25 were observed in 50% (20/40), 17.9% (7/39), and 8.1% (3/37) of the dogs after the administration of vincristine (VCR), cyclophosphamide (CPA), and doxorubicin (DXR), respectively. Blood/bone marrow adverse events occurring at least once during UW-25 were observed in 57.5% (23/40), 41% (16/39), and 8.1% (3/37) of the dogs after the administration of VCR, CPA, and DXR, respectively. The rate of patients that experienced gastrointestinal adverse events was higher after the first administration of VCR than after the first administration of DXR. Findings obtained in this study will be helpful in predicting the adverse events that could occur when dogs with lymphoma are treated with UW-25.