Candida albicans Urinary Tract Infection with Suspected Fungal Hepatobiliary Disease in an Immunosuppressed Dog: A Case Report.

Fungal urinary tract infections (UTIs) are uncommon in dogs and are typically associated with immunocompromised patients or those with other predisposing factors. Fungal hepatobiliary disease is rarely reported in the veterinary literature. This case report describes a dog on dual immunosuppressive therapy for suspected immune-mediated polyarthritis that developed a hepatopathy suspected to represent bacterial hepatobiliary disease and was subsequently treated with prolonged amoxicillin-clavulanate therapy. Following treatment, the dog developed marked hepatocellular enzyme elevations together with a Candida albicans UTI. Given the patient's progressive hepatocellular injury, clinical signs, history of immunosuppression and antibiotic therapy, concurrent fungal hepatobiliary involvement was suspected. Following initiation of oral fluconazole, the fungal UTI resolved, and there was marked improvement, with subsequent normalisation of ALT and ALP activities. Although the temporal association between antifungal treatment and clinical and biochemical improvement raised suspicion of concurrent fungal hepatobiliary involvement, simultaneous discontinuation of amoxicillin-clavulanate, substantial reduction in prednisolone dose, and continuation of hepatoprotective therapy precluded attribution of the improvement specifically to antifungal treatment. This case highlights the potential for opportunistic fungal disease in immunosuppressed dogs, particularly following prolonged antimicrobial exposure, and illustrates the diagnostic challenges associated with suspected hepatobiliary involvement.