Veterinary 2025 Guide: Melphalan (Alkeran®) for Cancer in Dogs & Cats 🐾🩺

I’m Dr Duncan Houston BVSc. In this in-depth 2025 guide, we review the use of melphalan—a cytotoxic alkylating agent used under the veterinary prescribing cascade—to treat cancers like lymphoma, multiple myeloma, sarcomas, and more. We’ll cover indications, dosing protocols, safety handling, monitoring, adverse effects, and client support with Ask A Vet tools 😊.

🔍 1. What Is Melphalan?

Melphalan (Alkeran®, L‑PAM) is a nitrogen mustard–type alkylator with high oral bioavailability. It crosslinks DNA, leading to cell death—especially in rapidly dividing cancer cells :contentReference[oaicite:3]{index=3}.

🎯 2. Key Indications

• Multiple myeloma: Standard first-line treatment in dogs and cats :contentReference[oaicite:4]{index=4}.
• Lymphoma: Used alone or with prednisone and/or cyclophosphamide :contentReference[oaicite:5]{index=5}.
• Sarcomas, mammary or ovarian tumors: Used off-label in select cases :contentReference[oaicite:6]{index=6}.
• Feline infectious peritonitis (FIP): Investigational use in cats, limited data :contentReference[oaicite:7]{index=7}.

📏 3. Dosing Protocols

• Myeloma (dogs): 0.1 mg/kg PO once daily ×10 days, then 0.05 mg/kg daily until remission or toxicity :contentReference[oaicite:8]{index=8}.
• Pulse protocol: 7 mg/m² PO daily ×5 days every 21 days in select cases :contentReference[oaicite:9]{index=9}.
• Cats: 0.1 mg/kg PO daily ×10–14 days, then every other day until response or myelosuppression. Maintenance every 7 days may follow :contentReference[oaicite:10]{index=10}.
• Larger tumors: Consult oncology—often combined with prednisone or cyclophosphamide :contentReference[oaicite:11]{index=11}.

🧤 4. Handling & Safety

Melphalan is hazardous: wear gloves when handling tablets, dosing pets, or disposing waste (urine, feces, saliva). Keep pets away from children during use and ensure secure storage :contentReference[oaicite:12]{index=12}.

⚠️ 5. Adverse Effects

• Myelosuppression: Expected after 7–14 days—monitor CBC every 7–14 days initially :contentReference[oaicite:13]{index=13}.
• GI signs: Anorexia, vomiting, diarrhea—managed with anti-emetics and supportive care :contentReference[oaicite:14]{index=14}.
• Pulmonary toxicity: Rare lung fibrosis—watch for coughing or tachypnea :contentReference[oaicite:15]{index=15}.
• Renal sensitivity: Use caution in pets with pre-existing kidney disease :contentReference[oaicite:16]{index=16}.
• Other: Lethargy, infections due to immunosuppression—prioritize hygiene and prophylaxis :contentReference[oaicite:17]{index=17}.

🩺 6. Monitoring Guide

• Baseline labs: CBC, chemistry, urinalysis before starting therapy.
• Follow-up CBC: Every 1–2 weeks during induction phase, then monthly on maintenance.
• Clinical signs: Monitor appetite, stool, energy, respiratory function, infections.
• Adjust dose or pause therapy if neutropenia, thrombocytopenia, or significant side effects occur.

🤝 7. Supportive Care & Combination Therapy

• Use anti-nausea meds and appetite stimulants as needed.
• Combine with prednisone and/or cyclophosphamide in lymphoma or myeloma protocols :contentReference[oaicite:18]{index=18}.
• Ensure hydration and treat infections promptly—hospitalize febrile neutropenic pets.
• Adjust dose for smaller or older pets to reduce toxicity risk.

📣 8. Client Communication & Home Care

• Explain the prescribing cascade and require informed consent.
• Demonstrate safe administration and glove use.
• Provide clear instructions on dosing schedule and side-effect signs.
• Use Ask A Vet app for treatment reminders, side-effect logs, and clinician communication 😊.

📌 9. 2025 Vet Takeaways

• Melphalan is a valuable alkylator for managing multiple myeloma, lymphoma, and select cancers in pets.
• Dosing protocols differ between dogs and cats—myelosuppression monitoring is critical.
• Strict safety handling precautions are essential for staff and clients.
• Supportive care, combination therapy, and regular monitoring optimize outcomes.
• Educate clients and leverage Ask A Vet tools to ensure compliance and safety 😊.

At Ask A Vet, we offer treatment trackers, lab reminders, safe-handling tutorials, and 24/7 vet messaging to support melphalan therapy. Download our app to improve oncology patient care and owner confidence ❤️