EXPRESS: Fungal pyelonephritis (Candida tropicalis) in a cat successfully treated with a subcutaneous ureteral bypass device and topical and systemic antifungals

Case summary A 12-year-old spayed female Ragdoll cat was treated with chemotherapy for gastric large B-cell lymphoma. Adverse effects included neutropenia and thrombocytopenia (Day 132) and transient prednisolone-induced diabetes mellitus (Day 209). On Day 209, urinalysis revealed yeast, and Candida tropicalis was cultured. Concurrent findings included mild azotaemia, hyperglobulinaemia, right renomegaly, and renal pelvic dilation. Chemotherapy was discontinued, and fungal pyelonephritis was treated with oral fluconazole (50 mg q12h). By Day 244, progressive right renal pelvic and ureteral dilation with echogenic ureteral material was noted. Management included placement of a subcutaneous ureteral bypass device (SUB), extended oral fluconazole (137 days), fluconazole administration into the renal pelvis via the SUB (10 days), and intravenous caspofungin (10 days). At final follow-up (Day 1306), the cat remained clinically well, non-azotaemic, with a patent SUB, reduced kidney size, and no recurrence of fungal urinary tract infection, lymphoma, or diabetes. Relevance and novel information This is the second report of feline Candida spp. pyelonephritis treated with a SUB, the first of topical antifungal treatment using a nephrostomy tube, resolution of predisposing factors and a successful long-term outcome.