Biopsies of the liver are important to direct treatment and define prognosis based upon a histological diagnosis. The decision to obtain a biopsy is based on the benefits of knowing the disease process versus the cost of the biopsy and risks to the patient. Characterization of liver disease depends on cytological and histological findings in tissues obtained via ultrasound-guided fine-needle aspiration, ultrasound-guided needle core biopsy, laparoscopic cup forceps biopsy, or biopsy by laparotomy. The biopsy technique selected is determined by the likelihood of the test sample being accurate, the appearance of the liver on imaging, the presumptive diagnosis, the results of coagulation tests, the risks for anesthesia and surgery, and the likelihood of postoperative complications. Ultrasound-guided biopsy and fine-needle aspiration have limited roles in diagnosing liver disease because of the high probability of inaccuracies, even in animals with normal livers.
Biopsies of the kidney are indicated less frequently than liver...