Myelofibrosis in a cat (abstract).

A 2-year-old female domestic shorthair cat was presented with ill-health and marked ascites. Clinically, there was marked pallor of mucous membranes. Two haematological examinations and transudate-exudate analyses of peritoneal fluid were conducted 1 week apart, as well as a coagulation screen and routine serum biochemistry. The haematological examinations revealed a severe persistent non-regenerative anaemia. There were no abnormalities within the neutrophil and lymphocyte cell lines. Very occasional nucleated red blood cells (RBCs) in peripheral circulation and some RBC agglutination were seen. Analysis of peritoneal fluid disclosed a modified transudate, and small numbers of erythroid and myeloid precursors were observed on the second occasion. The cat was FIV/FeLV-negative, and there were no coagulation abnormalities. Following necropsy and histopathological examination, myelofibrosis and extramedullary haematopoiesis were seen. Thoracic masses were hyperplastic lymph nodes in which there was evidence of extramedullary haematopoiesis. The exact cause of the myelofibrosis was not obvious but it may have been a case of myeloid metaplasia, however not all the characteristics of this entity were present.