LOPH PROTOCOL AND RESCUE WITH DOXORUBICIN, VINCRISTINE AND CYTARABINE IN THE CHEMOTHERAPY TREATMENT OF CHRONIC LEUKEMIA IN FELINE FELV POSITIVE

Abstract

Chronic leukemia is a myeloproliferative disorder considered rare in felines, affecting mainly elderly cats, and is also observed in animals carrying the feline leukemia virus (FeLV), which may be directly or indirectly associated with the oncogenesis of the neoplasm. The objective of this study was to report a case association between FeLV and chronic lymphocytic leukemia in a 5-year-old cat. In its first visit, the animal presented severe anemia (hematocrit 10%), leukocytosis (21,140/μL) due to lymphocytosis (44% of the total leukocytes) with the presence of circulating atypical mononuclear cells and clinical signs of mucosal pallor, progressive prostration and hyporexia. Blood transfusion was performed on day 0, and after 24 hours, bone marrow puncture was performed to obtain a definitive diagnosis by means of myelogram. During the first week, the animal showed clinical improvement and the myelogram result confirmed the suspicion of chronic lymphocytic leukemia. A rescue protocol with doxorubicin, vincristine, and cytarabine (OCH) was instituted, and five cycles were performed. During this period, it was necessary to perform four new blood transfusions due to episodes of anemia with worsening of the clinical picture, in addition to repeated episodes of neutropenia in which it was necessary to institute prophylactic antibiotic therapy and application of granulocyte and monocyte stimulating factor. After the fifth cycle, due to the persistence of hematological alterations and the reappearance of circulating atypical cells, the owner chose not to continue the treatment, and euthanasia was performed on the 226th day since her first consultation, obtaining approximately 7.5 months of survival.