Multiple myeloma in cats: treatment, prognosis and clinical trials
Cats · USA & Canada
Understanding multiple myeloma
Multiple myeloma is a cancer of plasma cells and is uncommon in cats. It can affect bone marrow, bones, kidneys, calcium levels and blood proteins, so diagnosis usually depends on several findings together. The organ complications it causes are often important in deciding how urgently treatment is needed.
What does the prognosis look like?
Feline myeloma is uncommon, so the evidence is limited. A 2024 multicenter study found a typical survival time of about 4 months overall, while older reports include individual cats living well beyond a year. Anemia, low platelets, kidney injury, high calcium and bone disease can shorten the course. The wide range means early treatment response is especially important.
What matters next
Start with the problems the plasma-cell disease is causing now: anemia, low platelets, kidney injury, high calcium, bone pain or fracture and effects of abnormal blood proteins. Those complications determine urgency and supportive care while systemic treatment is planned.
Where are you now?
There is kidney injury, high calcium, or severe anemia
These complications can be more immediately important than tumor burden itself. Stabilization and supportive treatment should happen alongside the cancer plan.
There is painful bone disease
Treat pain and assess fracture or spinal risk. Local radiation can sometimes help a focal painful lesion while systemic therapy addresses the plasma-cell disease.
Systemic treatment has started
Track the monoclonal protein or other disease markers together with blood counts, kidney values, and clinical response. Feline evidence is limited, so the individual cat’s response matters heavily.
If you are waiting for oncology
Assess kidney function, calcium, anemia, blood proteins and painful bone disease while confirming the diagnosis. In cats, the disease is uncommon enough that diagnosis should rest on the full pattern rather than one abnormal protein value.
Questions to ask your oncologist
- Which diagnostic criteria for myeloma are met in this cat?
- Are kidney injury, hypercalcemia or bone lesions present now?
- What marker will we follow to judge response to systemic treatment?
How the diagnosis may appear in the record
Feline myeloma is uncommon and diagnosis usually rests on several findings together. Keep protein studies, marrow or tissue results, imaging, calcium, kidney values, CBC, and the marker chosen to follow response rather than relying on a single abnormal protein result.
Changes to watch for at home
Watch for weakness, pale gums, bleeding, increased thirst or urination, vomiting, confusion, vision changes, bone pain, reduced jumping, or sudden inability to walk. Collapse, fracture, severe neurologic change, or profound weakness needs urgent care.
How it is usually treated
Systemic therapy is the main treatment because feline myeloma is generally disseminated. Alkylating chemotherapy with a corticosteroid is commonly considered. Radiation can help painful focal bone lesions, while supportive care addresses kidney injury, high calcium, anemia or other complications.
What can affect treatment choices
Kidney injury, high calcium, anemia, abnormal proteins, bone lesions, marrow involvement and response to therapy guide both treatment and monitoring.
Tests that may matter
CBC, chemistry, calcium, serum and urine protein studies, imaging for bone lesions and bone-marrow evaluation may all contribute. The goal is to confirm plasma-cell disease and identify anemia, kidney injury, high calcium, bone damage and abnormal proteins that may need immediate treatment.