Feline histoplasmosis: report of a fatal case

Abstract

A 4-month-old mixed-breed abandoned was submitted to a veterinary hospital for clinical examination. The patient presented poor conditions: low body condition, shaggy hair, and respiratory symptoms with ocular and bilateral nasal secretions. The physiological parameters showed tachycardia, dyspnea and fever; on auscultation, rales, stridor, wheezing and increased pulmonary dullness were noted. The results of complete blood count showed alterations associated with a regenerative anemia; moderate anisocytosis and polychromatophilia; deviation to the left with presence of bands and thrombocytopenia; intracytoplasmic inclusions compatible with Histoplasma sp. Radiological examinations showed a characteristic interstitial pattern relative to lung disease. Treatment was started with oxytetracycline IV (10 mg/kg/12 h) and ketoconazole PO (10 mg/kg/24 h), the most prescribed antifungal for these infections, as well as symptomatic supportive therapy. Unfortunately, the patient died despite all the efforts. Necropsy was performed. The presence of granulomas together with the histopathological findings confirmed the diagnose of histoplasmosis. The lesions observed microscopically suggest a multifactorial infectious process: first, a neoplastic disease (diffuse large cell lymphoma in bone marrow and lymph node) associated with feline leukemia virus, followed by systemic mycosis (especially in lungs and lymph nodes) caused by Histoplasma sp.