Antemortem diagnosis of Nannizziopsis guarroi fungal pneumonia in a green iguana (Iguana iguana)

Nannizziopsis guarroi is a highly pathogenic fungal organism affecting various lizard species which often manifests as cutaneous disease. Pulmonary involvement with Nannizziopsis infections has rarely been reported in reptiles. An 8-year-old, female green iguana was presented for clinical evaluation following a chronic history of upper and lower respiratory tract signs and fistula formation in the right maxilla communicating with the oral cavity. Pulmonary infiltrates were noted on serial computed tomography scans and repeated baseline bloodwork was unremarkable. Based on a poor response to chronic antibiotic therapy, rigid pulmonoscopy was elected. The lung parenchyma contained multifocal clusters of yellow-brown ovoid masses. Biopsy of the lesions revealed granulomas with intralesional fungal hyphae. Fungal culture had no growth but panfungal PCR identified the organism Nannizziopsis guarroi. The iguana failed to completely recover postprocedure and died despite further supportive care. Computed tomography helped determine the extent of pulmonary pathology but pulmonoscopy, lung biopsy and molecular diagnostic methods were ultimately required to obtain a definitive diagnosis. Nannizziopsis fungal pneumonia should be considered a differential diagnosis in squamates with respiratory clinical signs.