Evan’s Syndrome Hemolytic Anemia with Thrombocytopenia in a Labrador Dog: A Case Report

A seven-year-old Labrador retriever intact male dog was presented to the Referral Veterinary Polyclinic, Indian Veterinary Research Institute, Izatanagar with a history of inappetance, melena, and petechial hemorrhages on the ventral abdomen and treated by a local veterinarian for a prolonged period of time. Clinical examination showed pale mucous membranes, peripheral lymphadenopathy, and mild hepatomegaly. A Complete blood count revealed anemia, leukopenia, and thrombocytopenia and serum biochemistry showed hypoalbuminemia and hypoproteinemia. The dog was suspected of having a haemoprotozoan infection, and a thin peripheral blood smear was submitted to the Division of Parasitology, Indian Veterinary Research Institute, Izatanagar, Bareilly, for examination. A blood smear was screened for haemoprotozoan examination using Giemsa’s stain, which showed positivity for Babesia vogeli. An abdominal ultrasound confirmed hepatic enlargement. The blood clotting profile reveals an increase in activated partial thromboplastin time and prothrombin time. The dog's blood sample tested negative for Babesia vogeli, B. gibsoni, E. canis, and H. canis by multiplex PCR; this could be because of prior initiation of antibiotics. A periheral blood smear showed elevated spherocytes count and saline agglutination test was positive. Based on history, clinical examinations, laboratory findings and cytological examinations the case was tentatively diagnosed as chronic case of tick fever with concomitant Evans syndrome. A blood transfusion was performed and around 300 ml of whole blood was infused. Treatment was initiated with triple antibiotic therapy and an immunosuppressive dose of steroids, but after 4 weeks, the dog succumbed to the condition. Further research is required to optimize treatment regimens for dogs with Evan's syndrome, as the prognosis is uncertain.