Chemotherapy and remission status do not alter pre-existing innate immune dysfunction in dogs with lymphoma

•Dogs with lymphoma have an imbalance in pro-and anti-inflammatory cytokine production.•Following chemotherapy treatment, the cytokine imbalance did not improve.•Decrease in respiratory burst function was found in dogs with lymphoma after chemotherapy.

Dogs with lymphoma have altered innate immunity and little is known about the effects of chemotherapy on innate immune function in dogs. Lipopolysaccharide (LPS), lipoteichoic acid (LTA), and peptidoglycan (PG) – induced leukocyte cytokine production capacity, and phagocytosis and respiratory burst were evaluated in dogs prior to and following 6 weeks of chemotherapy. Dogs had decreased TNF production following LPS stimulation and increased IL-10 production following PG stimulation, which did not improve following remission of lymphoma. Dogs also had reduced E. coli-induced respiratory burst function after chemotherapy induced complete or partial remission. Dogs with lymphoma have an imbalance in pro-and anti-inflammatory cytokine production which did not improve with remission, and, following treatment, a decrease in respiratory burst function. Altered immune responses following exposure to bacterial pathogen associated molecular pattern motifs and bacteria may have many implications in the management of canine lymphoma.