Precursor‐targeted immune‐mediated anaemia in a dog with concurrent haemoparasite seroreactivity: Diagnostic challenges and therapeutic response

Summary Precursor‐targeted immune‐mediated anaemia (PIMA) is an increasingly recognised cause of nonregenerative anaemia in dogs and may be difficult to distinguish from infectious or other immune‐mediated conditions. This report describes a dog presenting severe nonregenerative anaemia, leukopenia and thrombocytopenia, initially testing seroreactive for Anaplasma spp. and Ehrlichia spp., with simultaneous identification of Hepatozoon spp. gamonts on blood smear. Despite antimicrobial therapy and corticosteroid administration, anaemia persisted with inadequate reticulocyte response. Cytological evaluation of the bone marrow revealed marked erythroid hyperplasia, decreased myeloid‐to‐erythroid ratio, and evident rubriphagocytosis, supporting a diagnosis of PIMA. Combined immunosuppressive therapy with prednisolone and mycophenolate mofetil resulted in progressive haematological recovery, with normalisation of haematocrit by the third month of treatment. This case highlights the diagnostic challenges of differentiating PIMA from haemoparasitic diseases and emphasises the importance of bone marrow evaluation in dogs with persistent nonregenerative anaemia.