💊 Vet-Approved Guide to Common Lymphoma Chemotherapy Medications for Dogs and Cats (2025) 🐶🐱

By Dr Duncan Houston BVSc

Lymphoma is one of the most common cancers in dogs and cats—and also one of the most treatable with chemotherapy 💉. While the term “chemotherapy” might sound scary, pets typically tolerate treatment much better than people. In this 2025 guide, Dr Duncan Houston explains the key medications used in lymphoma treatment and what to expect 🧬.

🧠 What Is Chemotherapy?

Chemotherapy refers to using medication—rather than surgery or radiation—to treat cancer. In lymphoma, chemo is often the first line of treatment and can lead to months or even years of remission in pets 🩺.

💡 Good to know: Pets don’t receive the same aggressive doses used in human medicine. This means:

• 😷 Side effects are usually mild
• 🎯 Quality of life remains a top priority

📊 Protocols and Planning

Chemotherapy can be:

• 🔄 Multi-drug protocols (e.g., CHOP, COP, MOPP)
• 💊 Single-agent therapy (one drug used repeatedly)

📉 After remission, some pets eventually relapse. At that point, a different “rescue protocol” is used with drugs not previously given.

💡 CHOP Protocol

One of the most commonly used protocols for dogs with lymphoma. CHOP stands for:

• 💉 C – Cyclophosphamide
• 💉 H – Doxorubicin (Hydroxydaunorubicin)
• 💊 O – Vincristine (Oncovin)
• 💊 P – Prednisone

Many cats are treated with simpler protocols or single-agent therapy due to size and tolerance differences 🐱.

🧪 Common Chemotherapy Drugs for Lymphoma in Pets

1. 🩸 Doxorubicin (Adriamycin)

• 🧬 Powerful anti-cancer agent in CHOP
• 📆 Given every 3 weeks IV
• 🧠 Side effects: vomiting, diarrhea, low white cells

2. 💊 Cyclophosphamide (Cytoxan)

• 🧪 Alkylating agent used orally or IV
• ⚠️ May cause sterile hemorrhagic cystitis (bloody urine)

3. 💉 Vincristine (Oncovin)

• ⚡ Disrupts cell division
• 📆 Weekly injections
• 🧠 Commonly causes constipation, low white cell counts

4. 💊 Prednisone or Prednisolone

• 🌿 Corticosteroid used to reduce cancer burden and inflammation
• 💊 Often the first drug used (even before a full diagnosis)
• ⚠️ Long-term use can suppress immune system and increase side effects

5. 💉 L-Asparaginase (Elspar)

• 🎯 Targets lymphoma’s protein needs
• 📈 Often used early for rapid results
• ⚠️ Can cause allergic reactions

6. 💊 Chlorambucil (Leukeran)

• 🧪 Mild oral chemo agent
• 👍 Ideal for feline lymphoma (especially GI form)

7. 💊 Lomustine (CCNU)

• 🧬 Oral chemo used in rescue protocols
• ⚠️ Can cause liver toxicity—monitor bloodwork!

8. 💊 Methotrexate

• 🧠 Interferes with DNA synthesis
• 📆 Used in select protocols

9. 💊 Procarbazine

• Part of MOPP protocol
• Used more often in rescue plans or special cases

10. 🧬 Rabacfosadine (Tanovea-CA1)

• 💉 Newer drug with conditional FDA approval
• 📆 Given every 3 weeks
• ⚠️ May cause lung or skin side effects

11. 🧬 Verdinexor (Laverdia-CA1)

• 💊 Oral chemo option
• 🧪 Also conditionally approved for canine lymphoma

📉 Side Effects and Monitoring

• 📋 Most pets tolerate chemo well
• 🔁 Regular bloodwork to monitor white cells and organ function
• 💊 Anti-nausea and anti-diarrhea meds often prescribed proactively

🐾 Only about 10–20% of pets experience side effects, and they are typically mild and manageable.

🔁 What Happens After Remission?

• 🎯 Many pets achieve remission—symptoms disappear
• 📆 Median remission length in dogs: 6–12 months
• 🔁 If relapse occurs, a rescue protocol with different drugs is used

🧠 Key Takeaways

• 🧪 Chemotherapy for pets is not as harsh as in people
• 📋 Many protocols are available, tailored to cancer type and species
• 🎯 Early detection and aggressive treatment improve success

📲 Final Advice from Dr Duncan Houston

Lymphoma may sound overwhelming, but many pets go into remission and enjoy months or years of good quality life. Your vet or veterinary oncologist will help choose the best protocol based on your pet’s diagnosis and tolerance 💪.

📱 For help managing chemotherapy at home, interpreting lab results, or choosing the right protocol, download the Ask A Vet App or visit AskAVet.com. We’re here every step of the way 💬🐾.