Cyclosporine as a Novel Therapeutic Option for Eosinophilic Cystitis in a Paraplegic Dog.

Eosinophilic cystitis is characterized by eosinophilic infiltration and proliferation within the layers of the bladder wall. Its etiology remains unclear, and there is no established consensus regarding treatment in either human or veterinary medicine. A 4-year-old female dog developed paraplegia after a car accident, with a spinal cord injury in the lumbar region diagnosed by radiography. Five months after the trauma, the animal began to present with hematuria and recurrent episodes of urinary tract infection, with an unsatisfactory response to conventional therapies with bladder emptying management and antibiotics for 1 year. Bladder wall biopsy revealed findings consistent with eosinophilic cystitis. Due to the persistence of clinical signs, cyclosporine treatment was initiated, alongside previous surgery and antibiotics, resulting in significant clinical improvement, normalization of bladder ultrasonographic findings, and no observed adverse effects during the treatment period. The medication was continued for 6 months, followed by a gradual tapering. Six months after discontinuation, the animal remained asymptomatic. This case highlights the potential use of cyclosporine in the treatment of eosinophilic cystitis and supports the hypothesis that spinal cord injury may represent a possible risk factor for EC in dogs. It also emphasizes the importance of including EC in the differential diagnosis of bladder wall thickening. This report has some limitations, including the evaluation of a single patient, the use of concurrent therapies, and the absence of serum cyclosporine level monitoring.