Pneumonia piogranulomatosa fúngica em canino

Abstract

Pneumonias are complex and serious alterations of the lung lobes caused by diverse etiologies, with important pathological variations that are difficult to diagnose through imaging. In this context, an unusual or rare presentation is pulmonary zygomycosis, which usually affects immunosuppressed animals. Given the low occurrence of the condition and the absence of a pattern of lesion distribution in the literature, this report was developed with the objective of describing the clinical-laboratory, radiographic, ultrasonographic and histopathological findings of a dog treated at a university veterinary hospital in Cuiabá, in the central-west region of Brazil, with diffuse pyogranulomatous pneumonia associated with zygomycete fungi. The dog presented with hyporexia, progressive weight loss and a lot of coughing. On physical examinations, clinical signs such as tachypnea, dehydration, slightly pale mucous membranes, crackles on pulmonary auscultation, nasal secretion, open wound in the perianal region and general depressed condition were observed. Imaging tests showed increased radiopacity in lung fields (thoracic radiography) and consolidation/hepatization of the lung lobes of the right hemithorax (thoracic ultrasound). The dog was hospitalized for further care, but euthanasia was later decided. At necropsy, the right lung surface was yellowish-white with caseous material and involvement of several lobes. In the microscopic analysis, replacement of the lung parenchyma was observed by an inflammatory infiltrate (composed of mononuclear, epithelioid and multinucleated cells, a smaller number of neutrophils and lymphocytes that surround areas of amorphous hyaline material with basophilic mixtures – caseous necrosis) and structures similar to hyphae, being associated with zygomycete fungi. This report reinforced the severity of the disease, especially in immunosuppressed animals, and the importance of performing additional tests, such as laboratory and imaging tests, in order to reach an earlier and assertive diagnosis.