CANINE AUTOIMMUNE HEMOLYTIC ANEMIA SECONDARY TO CHRONIC EHRLICHIOSIS: A CASE REPORT.

Resumo

Immune-mediated hemolytic anemia (IMHA) is a disease characterized by the lysis of erythrocytes by autoantibodies, which can occur primarily or secondarily, triggering significant systemic alterations and compromising tissue oxygenation. Canine ehrlichio sis is an infectious disease caused by the bacterium Ehrlichia canis and transmitted by the brown dog tick (Rhipicephalus sanguineus). Among the alterations developed by the disease are anemia and thrombocytopenia. Furthermore, ehrlichiosis can be classified as acute, with easy diagnosis and a good prognosis, and chronic, where diagnosis is difficult and the prognosis is guarded, potentially triggering autoimmune diseases. This paper aims to report the clinical case of a canine with hematological alterations compatible with immune -mediated hemolytic anemia and a confirmed diagnosis of chronic ehrlichiosis, emphasizing the clinical and laboratory findings observed during veterinary care. The study followed ethical guidelines through a retrospective analysis o f clinical records supported by a Free and Informed Consent Form (TCLE) signed by the owner. The patient was treated at the Veterinary Hospital of the University of Marília. She was a three -year-old mixed- breed female dog weighing 8 kg, presenting with anorexia for four days, in addition to episodes of yellowish vomiting and one episode of dark stools three days prior. On physical examination, the animal presented with elevated body temperature, tachycardia, tachypnea, and a capillary refill time of two sec onds, estimated dehydration of 10%, pale mucous membranes, reactive submandibular lymph nodes, a body condition score of 5/9, and splenomegaly. Diagnostic methods included a complete blood count showing severe and progressive anemia, a strongly positive saline agglutination test, and a detectable IgG (Immunoglobulin G) Dot Blot serological test for Ehrlichia sp. The therapeutic protocol was instituted with Doxycycline 8mg/kg BID, Azathioprine 1mg/kg SID, Mycophenolate 10mg/kg BID, and Prednisolone 2mg/kg BI D; however, due to intense hemolysis, the patient progressed to severe anemia, culminating in the animal's death. Therefore, it is concluded that the observed clinical and laboratory findings suggest a picture compatible with immune-mediated hemolytic anemia secondary to chronic ehrlichiosis, highlighting the importance of the association between physical examination and hematological evaluation for the diagnosis of the disease. Thus, early recognition of clinical signs and laboratory changes is fundamental for the rapid institution of therapy and improvement of the patient's prognosis.