What are the best alternatives to CHOP for canine lymphoma in clients who decline standard multi-agent protocols?

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For clients declining CHOP, the three evidence-supported alternatives are single-agent doxorubicin (DOX) plus prednisone, single-agent rabacfosadine (RAB), and alternating RAB/DOX — each offering a meaningful step up from prednisone alone while requiring substantially fewer visits than CHOP. Prednisone alone is the floor, not a treatment. Median survival time (MST) with prednisone alone is 1–2 months, compared to approximately 1 year with CHOP. 14 It is appropriate only when all chemotherapy is declined. Single-agent DOX plus prednisone is the most practical step-down from CHOP for B-cell lymphoma. DOX is administered once every 3 weeks for 5–6 treatments — 5 to 6 visits total versus 12–17 for CHOP. 1 Overall response rates are 74–88%, with remission durations of 4–6 months and survival times of 5–9 months. 1 Critically, these outcomes are drawn from mixed immunophenotype populations; dogs with B-cell lymphoma specifically show a 100% response rate to a single DOX dose, compared to 50% for T-cell lymphoma, so this protocol is best reserved for confirmed B-cell disease. 1 The AAHA guidelines list single-agent chemotherapy as an accepted option with MST under 1 year. 14 Rabacfosadine (RAB, Tanovea-CA1) at 1.0 mg/kg IV every 21 days for up to 5 treatments is FDA-conditionally approved for canine lymphoma and is an established single-agent alternative. 68 As a single agent, RAB achieves response rates of 74–100% across naïve and relapsed disease. 6 In a placebo-controlled trial, RAB produced a median progression-free survival (PFS) of 82 days overall versus 21 days for placebo; in treatment-naïve dogs specifically, median PFS was 143 days versus 19 days for placebo. 6 The overall best objective response rate was 73.2% for RAB versus 5.6% for placebo. 6 The AAHA guidelines report an MST of approximately 6 months with RAB. 14 Response rates and durations are better in B-cell than T-cell lymphoma, and in dogs with fewer prior treatment lines. 6 Alternating RAB/DOX is the h