Immune-Mediated Hemolytic Anemia Associated with A Thymoma in a Pet Rabbit.

A 5-year-old Siamese female spayed rabbit (Oryctolagus cuniculus) presented for acute onset of anorexia and tachypnea on August 19, 2021. The patient had history of thymoma diagnosed in February 2021. Upon clinical examination as well as with both radiography and ultrasonography (Fig 1) there was evidence of an enlarged thymoma as compared to the imaging done in February. There was also skin pallor (Fig 2). Ultrasonographically it appeared there was a fluid-filled thymic cyst. Hematology revealed a severe regenerative anemia, thrombocytopenia, leukopenia and lymphocytosis and other abnormalities (Fig 3). A diagnosis of immune-mediated hemolytic anemia (IMHA) was based on the severe regenerative anemia, presence of spherocytes and weak positive saline agglutination test result (Table 1). Oral prednisolone at 2 mg/kg along with a gastrointestinal protectant was prescribed. Supportive care including thoracocentesis to reduce the size of the thymic cyst, blood transfusion, assist-feeding and oxygen supplementation were also provided. The patient's clinical signs improved gradually while the PCV increased from 13.7-28.7% in 3 weeks. The percentage of poikilocytosis decreased on blood film examination. The gradual reduction of the prednisolone dose started two weeks after the initial dose and was reduced 25% by every week due to the concern of the side effects of the corticosteroid. [ABSTRACT FROM AUTHOR]