A case report of cryptococcosis in a captive Cape hyrax (Procavia capensis)

Abstract

Cryptococcosis, a globally distributed mycotic disease caused by Cryptococcus neoformans or C. gattii, has been extensively studied in various domestic animals and humans. However, non-domestic species have often been overlooked in the literature, with limited attention given to their susceptibility and contribution to the epidemiology of the disease. In this study, a captive two-year-old Cape hyrax in a Japanese zoo exhibited neurological symptoms and torticollis, ultimately succumbing to the infection. Necropsy and pathological analyses, including histopathological techniques and PCR, revealed the presence of C. neoformans in the lungs, cerebrum, and internal auditory canal. While cryptococcosis has been reported in various wild animals globally, this case represents the first documented cryptococcosis in Cape hyrax.

Keywords: Cape hyrax; Cryptococcus neoformans; fungus; pneumonia; wildlife.

Fig. 1.

Radiographic examination of the Cape hyrax. The right auditory canal shows slight hyper-opacity.

Fig. 2.

Pathological findings of Cryptococcosis in a Cape hyrax. (A) A 2 cm-sized white lesion was confirmed in its anterior lobe. (B–F) The yeast fungi 15 to 20 μm in diameter with prominent capsule are observed in the lung (B); around meninges (C); and cochlear nerve admixed with crystal formation (D). H&E staining. Scale bars=100 μm. (E, F) Cryptococci are stained with PAS staining (E); and stained black in Grocott’s variation screaming fungus staining (F). Cryptococci with narrow-based budding morphology are seen (arrowheads). Scale bars=50 μm.

Fig. 3.

Identification of Cryptococcus with PCR. Lane 1; PCR product (136 bp) using CN4 and CN5 primers. Lane 2: PCR product (241 bp) using cn1 and cn2 primers.