Canine Multiple Myeloma

Canine multiple myeloma is a malignant plasma cell neoplasm affecting primarily middle-aged to older dogs, characterized by monoclonal gammopathy, osteolytic bone lesions, and Bence-Jones proteinuria. Neoplastic plasma cells proliferate in the bone marrow and secrete excessive immunoglobulins, often leading to hypercalcemia, renal impairment, and hyperviscosity syndrome.

Clinical signs include lethargy, bone pain, PU/PD, and bleeding or neurologic deficits. Diagnosis requires identification of a monoclonal spike on electrophoresis, plasmacytosis, and radiographic bone lysis. Treatment involves melphalan with corticosteroids, supportive care, and bisphosphonates. Remission is common, but long-term control depends on systemic involvement and therapeutic response.

Canine Transitional Cell Carcinoma

Transitional cell carcinoma is the most common malignant tumor of the canine urinary tract, typically arising in the trigone region of the bladder. It presents with signs mimicking urinary tract infection—stranguria, hematuria, pollakiuria—and may progress to urethral obstruction or metastasis. Diagnosis involves imaging, urine cytology, and definitive confirmation with BRAF mutation testing or biopsy. Treatment is challenging due to tumor location, with options including NSAIDs (piroxicam), chemotherapy, and palliative care.

Canine Lymphoma

Canine lymphoma is a common hematopoietic malignancy, most often presenting as multicentric lymphadenopathy. It typically arises from B lymphocytes and can affect multiple organ systems including lymph nodes, spleen, liver, gastrointestinal tract, and bone marrow. Diagnosis is based on cytology or histopathology, with immunophenotyping (B vs. T cell) providing prognostic value. Treatment of choice is multi-agent chemotherapy (e.g., CHOP protocol), which can induce remission in most cases, though relapse is common.