CHOP protocol for canine lymphoma

Of course, happy to outline the standard CHOP-based protocol we use for canine multicentric B-cell lymphoma. This is a well-established protocol, often referred to as the UW-Madison protocol, and it remains our first-line recommendation for most cases.

The primary goal is to induce a complete remission, which we achieve in 85-90% of B-cell lymphoma cases. The median survival time (MST) is typically 12-14 months. For T-cell lymphoma, the prognosis is more guarded, with an MST of around 6-9 months, but CHOP is still the protocol of choice.

Here is the typical 25-week induction schedule. Each "cycle" is 4 weeks long, with a one-week break after doxorubicin.

CHOP Protocol (UW-Madison)

* Week 1: Vincristine 0.7 mg/m² IV
Concurrent:* Prednisone 2 mg/kg PO daily for one week, then taper by 25% each week for 4 weeks.
* Week 2: Cyclophosphamide 250 mg/m² PO
Note:* Administer with furosemide (1-2 mg/kg PO) to mitigate risk of sterile hemorrhagic cystitis. Give in the morning to encourage urination throughout the day.
* Week 3: Vincristine 0.7 mg/m² IV
* Week 4: Doxorubicin 30 mg/m² IV slow infusion
* Week 5: Rest week (no chemotherapy)

This 5-week block is repeated for a total of 5 cycles (25 weeks).

Key Monitoring & Counseling Points:
* Pre-Doxorubicin: Always perform an echocardiogram before the first dose of doxorubicin to establish a baseline, especially in predisposed breeds (Dobermans, Boxers, etc.). Track the cumulative dose; cardiotoxicity risk increases significantly above 180 mg/m².
* Bloodwork: A CBC should be checked before every chemotherapy administration. We're looking for an absolute neutrophil count (ANC) >1,500/µL and platelets >50,000/µL before proceeding. A nadir CBC 7 days after the first vincristine and cyclophosphamide is wise to assess for individual sensitivity.
* GI Support: Prophylactic anti-emetics like maropitant are highly recommended, especially on doxorubicin and cyclophosphamide days.
Prednisone Warning: Remember to confirm the diagnosis before* starting prednisone, as it can induce multi-drug resistance and make the CHOP protocol less effective.

Let me know if you want to discuss dose modifications for toxicity or potential rescue protocols.