Monoclonal gammopathy in a Dutch warmblood mare

Abstract

SUMMARYA 15-year-old Dutch warmblood mare was presented because of lethargy, which had been present for several weeks, and severe anaemia. Total protein was high and serum electrophoresis revealed a monoclonal peak in the alpha-2 region. Monoclonal immunoglobulin, IgG(T), was detected by immuno-electrophoresis in serum and urine. Postmortem examination revealed a relatively large number of plasmacytoid cells in the bone marrow and a monotonous population of plasmacytoid cells in the spleen.These findings are suggestive of a plasma cell myeloma.

Multiple Myeloma in Horses, Dogs and Cats: A Comparative Review Focused on Clinical Signs and Pathogenesis

“…Clinically, hemorrhages occur in approximately one-third of dogs and one fourth of cats with MM [4,27,29]. In horses, the most common clinical manifestation is epistaxis [1,3,6].…”

“…Data concerning white blood cell count (total and different subpopulations) are not consistent in animals with MM. It has been found lymphopenia [24,30,32], leukocytosis due to neutrophilia [4,8], neutropenia with lymphocytosis [31], leukopenia [1,25,37], leukocytosis with neutrophilia and lymphocytosis [31], neutropenia [16], neutrophenia with lymphopenia [18], pancytopenia [10] and absence of white blood cell abnormalities [3,6,22].…”

“…It has also been described in cats [4,29] and horses [18,37]. However, there are many other reports of MM in veterinary medicine with patients that show normal number of platelets [3,[6][7][8]16,22,24,[31][32]. Thrombocytopenia that could promote bleeding disorders, is proposed to result from infiltration of bone marrow by malignant plasma cells, consumption of platelets as part of thrombohemorrhagic syndrome, such as disseminated intravascular coagulation, shortened platelet half-life or immune-mediated destruction, even though the latter 2 mechanisms have yet to be verified in veterinary medicine [10,27,30,64,[142][143].…”

“…Multiple myeloma (MM) or plasma cell myeloma is a neoplastic proliferation of plasma cells that primarily involves the bone marrow but may originate from extramedullary sites [1][2][3][4]. Although it is uncommon in veterinary medicine, it has been reported in several species, including cats, dogs and, horses [1,3,[5][6][7][8][9][10]. The frequency of MM in cats is slightly <1% of all malignant neoplasms.…”

“…Similarly, MM is an extremely rare disorder in horses. Ten cases, nine from the literature and a new case, were described by Edwards et al [1] and only six additional cases have been described lastly [3,[6][7][8]18]. Because of the uncommonly diagnosis of equine MM, the prevalence of this neoplasm is unknown in the horse.…”