Three African spurred tortoises (Centrochelys sulcata) were referred for inappetence and lethargy of 1 week's duration. On presentation, one animal was confirmed dead and submitted for necropsy. The conspecifics were treated symptomatically for upper respiratory tract disease. The deceased individual tested negative for herpes‐, rana‐ and picornavirus but positive for Mycoplasma agassizii by polymerase chain reaction (PCR), however, without exhibiting pathological changes consistent with this infection. Instead, systemic mycosis was diagnosed, with isolation of Candida steatolytica. This allowed effective targeted treatment of the remaining animals. Candida steatolytica is commonly isolated from rotting fruits and has so far been rarely associated with clinical disease. In the present cases, the most likely source of infection was pruned vine shoots and leaves, which the tortoises had access to in their outdoor paddock. This case highlights the significance of rapid and comprehensive post‐mortem diagnostics with swift interdisciplinary communication to allow effective handling of challenging cases.