Multiple Myeloma in Dogs – Vet‑Led Guide 2025 🐶🩸

🩺 Multiple Myeloma in Dogs – Vet‑Led Guide 2025 🐶🩸

By Dr. Duncan Houston BVSc

Hello, I’m Dr Duncan Houston, BVSc, founder of Ask A Vet. In this 2025 guide, we delve into multiple myeloma—a rare but treatable cancer of plasma cells. We’ll cover causes, symptoms, diagnosis, first-line chemo, prognosis, and home care strategies to support your pup’s quality of life. 🐾

📘 What Is Multiple Myeloma?

Multiple myeloma is a cancer of plasma cells that develop in the bone marrow. These malignant cells overproduce monoclonal antibodies (M-component) and infiltrate multiple sites—leading to bone lesions, blood thickness (hyperviscosity), bleeding, anemia, kidney damage, and immune suppression.

It accounts for < 1% of dog cancers, typically affects older breeds like Labradors, Golden Retrievers, and German Shepherds.

🚩 Clinical Signs

Lethargy, weakness, weight loss
Lameness or bone pain; fractures are possible
Bleeding issues (gums, nose, bruising)
Excessive thirst/urination, hypercalcemia
Eye issues: retinal hemorrhage, vision changes
Infections due to immune suppression
Neurological signs or organ involvement

🔬 How We Diagnose It

At least two of the following criteria are required:

Bone lesions on X-ray/CT (up to 65% of dogs)
Bone marrow plasma cells >20–25%
Monoclonal gammopathy in serum via electrophoresis (99% include M-component)
Detection of Bence‑Jones proteins in urine

Additional tests include CBC, chemistry, urinalysis, abdominal ultrasound, and coagulation profiles to assess systemic impact.

💉 Treatment Plans

1. Chemotherapy (First-Line)

Melphalan + Prednisone: oral, daily-then-maintenance protocol, or pulse dosing
Tolerated well; monitor CBC every 2–4 weeks
80–95% response; clinical improvement in 3–6 weeks; MST 18–30 months (∼540 days)

2. Rescue Protocols

At relapse, use alkylating agents (cyclophosphamide, chlorambucil, lomustine), or chemo combos (vincristine + doxorubicin), or emerging rabacfosadine (∼80% response in small study).

3. Supportive & Adjunct Therapies

Bisphosphonates (pamidronate) for bone pain & hypercalcemia
IV fluids for hyperviscosity or renal support
Packed cell/platelet transfusions for bleeding
Plasmapheresis in acute hyperviscosity (rare use)
Pain relief: NSAIDs, opiates, supportive care
Antibiotics to prevent infections
Radiation therapy for focal bone pain

📅 Prognosis & What to Expect

92% of dogs achieve remission (complete: 43%, partial: 49%) with melphalan/prednisone
MST ~540 days (~18 mo); some reach 2–2.5 years
Negative prognostic factors: hypercalcemia, renal failure, extensive bone lesions, Bence‑Jones proteinuria
Regular bloodwork tracks response, warns of relapse
Relapse anticipated—response to rescue therapies can extend life further

🏡 Home Care & Quality‑of‑Life Support

Regular CBC/chem follow-ups (every 4 weeks or per vet)
Pain management: give medications as prescribed
Bone-strengthening diet & omega‑3 fatty acids
Comfortable environment: soft bedding, ramps
Hydration support—ensure available fresh water or wet foods
Gentle exercise—avoid fractures but maintain muscle tone
Monitor appetite, energy, lameness, bleeding, thirst, or urination changes

🐾 Supporting Owners & Pets

Facing cancer? Get 24/7 answers from Ask A Vet—on dosing, side effects care, or wellness. Together, we focus on comfort, connection, and hope. 💕

✨ Key Takeaways

Multiple myeloma is treatable—chemo leads to remission in over 90% of dogs.
Diagnosis requires ≥2 criteria: bone lesions, plasmacytosis, monoclonal proteins, or Bence‑Jones proteinuria.
First-line melphalan + prednisone offers MST ~18 mo; relapse treatments extend lifespan further.
Supportive care—bisphosphonates, fluids, pain relief—is vital for comfort.
Frequent monitoring ensures early detection of relapse or complications.
Combining clinical care with home comfort resources keeps happy days in focus.

If you suspect multiple myeloma, or have a diagnosis and treatment questions, contact your vet or Ask A Vet. We’re here with science, empathy, and your pup’s well-being at heart. 🐾❤️