Therapeutic Outcomes of Injectable Filgrastim in Eight Dogs Affected with Persistent Fever, Acute Leukopenia, and Neutropenia
Filgrastim is a recombinant methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF) analog used to stimulate the proliferation and differentiation of granulocytes in humans undergoing chemotherapy. Recently, dogs with persistent fever (T-105°F), severe acute leukopenia, and neutropenia (below 600 cells/mm) have been presented with high mortality and were taken for study. Leukopenia from reduced production of white blood cells or increased utilization and destruction, or both are fatal. Apart from identification of the cause and effective antimicrobial therapy, recently the treatments are aimed in increasing the leukocyte counts to fight infections and related sepsis.
To evaluate leukopenic dogs with persistent fever, post-treatment with single dose subcutaneous filgrastim injection (Neupogen®).
Routine diagnostic tests including ultrasonography, radiography, lymph node aspirations, blood smears were done on affected dogs for confirmation. These severely leukopenic dogs were treated with injection filgrastim @ 10 μg/kg b.wt subcutaneously single dose along with CRI crystalloid therapy. Clinical pathological studies were done pre- and post-treatments on day 1, day 2, day 3, and day 5 following filgrastim administration.
Seven dogs with severe leucopenia (<600 cells/cmm) responded clinically within 72 hours and their leucocyte counts increased considerably (4,200–5800 cells/cmm). One dog succumbed without clinical and clinical pathological response. No adverse reactions were encountered within 24 hours post filgrastim injections subcutaneously.
Filgrastim increased the leukocyte counts within 72 hours thereby improving the survival rates in affected dogs showing early critical SIRS. Further clinical trials need to be emphasised based on these findings.