Corneal stromal metastasis of urothelial carcinoma in a dog

A 15-year-old intact male Miniature Dachshund presented with severe hematuria. Clinical evaluations of this dog raised the suspicion of a malignant bladder tumor, and corneal stromal opacity was observed in the left eye. Because of the critical condition, the dog died on the day of presentation, after which a necropsy was performed. Necropsy and histopathological examinations confirmed urothelial carcinoma (UC) in the bladder. Moreover, the corneal stromal opacity represented a metastatic lesion of UC, and similar metastatic lesions were identified at 13 other sites. The UC in this dog was considered clinically highly malignant based on its rapid clinical course and the presence of multiple metastatic sites. This highly malignant nature may have contributed to the corneal stromal metastasis. This is an extremely rare case of corneal stromal metastasis from canine UC.