EPO and anemia: At 24 hpi, GO terms such as response to erythropoietin, cellular response to erythropoietin, erythropoietin-mediated signaling pathway and erythrocyte maturation were significantly enriched in the bone marrow of infected puppies,, which may be a compensatory response to visceral injury and anemia of the puppies caused by T. canis infection at the early stage.