Abstract
All animals scheduled for urinary tract biopsy should undergo a complete historical and physical evaluation. Laparoscopic‐assisted percutaneous needle core biopsies may obtain more representative tissue than US‐guided biopsies, and the biopsy site can be watched for evidence of hemorrhage. Fine needle aspirate (FNA) and needle core biopsy (e.g. Trucut) are infrequently used to diagnose renal tumors, possibly due to the concerns of abdominal tumor seeding associated with biopsy bleeding or biopsy‐tract implantation. Incisional or wedge biopsies will yield large tissue samples for histopathology and are typically taken from the junction of normal and what appears to be abnormal kidney. The majority of urinary neoplasia is epithelial in origin, and urothelial carcinomas display aggressive malignant behavior. For tumors that involve the urethra or trigone of the bladder and that cause an obstruction, placing a cystostomy tube can be a palliative solution to allow emptying of the bladder by the owners.