Asparaginase and MOPP treatment of dogs with lymphoma.

BACKGROUND: Dogs with multicentric lymphoma are treated with various cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based chemotherapy protocols with variable success. OBJECTIVES: To describe the progression-free survival (PFS) time and overall survival time (OST) of dogs with T-cell lymphoma or hypercalcemic lymphoma treated with L-asparaginase and mechlorethamine, vincristine, prednisone, procarbazine (MOPP). ANIMALS: Fifty dogs with T-cell lymphoma, hypercalcemic lymphoma, or both treated at 3 referral veterinary hospitals. METHODS: Retrospective study. Case were selected based on histologic or cytologic diagnosis of lymphoma; presence of the T-cell phenotype, presence of hypercalcemia or both; and absence of previous chemotherapy. The T-cell phenotype was determined by flow cytometry, immunocytochemistry, immunohistochemistry, or polymerase chain reaction of antigen receptor rearrangement. RESULTS: The overall response rate was 98% (78% complete response, 20% partial response). The median PFS for the entire study population was 189 days with 25% PFS at 939 days. The median OST for the entire study population was 270 days with 25% surviving 939 days. Twenty percent of the dogs required hospitalization for treatment related complications. CONCLUSIONS AND CLINICAL IMPORTANCE: L-Asp/MOPP chemotherapy might result in longer PFS and OST for dogs with multicentric T-cell lymphoma, dogs with hypercalcemic lymphoma or both, than achieved with CHOP.

Acquired amegakaryocytic thrombocytopenia--four cases and a literature review.

Acquired amegakaryocytic thrombocytopenla was diagnosed in four dogs. Initial platelet counts in all four dogs were less than 50,000 x 10(9)/litre and initial bone marrow examinations revealed megakaryocytic hypoplasia with minimal changes in the erythroid and myeloid cell lines. Two dogs had evidence of idiopathic immune-mediated disease and two dogs had evidence of associated infectious disease. One dog had a positive antibody titre to Borrella burgdorferi, and one dog had positive titres to both Ehrlichia canis and B. burgdorferi. Treatment consisted of prednisone and cyclophosphamide for the dogs with presumptive immune-mediated disease, and prednisone and tetracycline for the dogs with positive antibody titres to the Infectious organisms. Both dogs with evidence of associated infectious disease responded to treatment. A postmortem examination did not reveal the underlying aetiology in the two dogs with presumptive idiopathic immune-mediated disease.