Development of a technique for serial bilateral renal biopsy in steers.

A biopsy procedure was developed to provide serial kidney samples from standing steers. Ten clinically normal steers were given intramuscular injections of gentamicin sulfate, 4 mg/kg body weight. Renal biopsy was performed at 5 separate times. After feed was withheld for 24 h, laparoscopic surgery was performed in standing stocks. Acepromazine, xylazine, and butorphanol were used for sedation and analgesia, and 2% lidocaine was used for local anesthesia. Two incisions approximately 2 cm long were made in the paralumbar fossa to allow for trocar introduction. The abdomen was insufflated with CO2 and, with endoscopic guidance, a biopsy forceps used to remove a kidney sample 2 to 3 mm in diameter, by either a left or a right abdominal approach. Each operation was recorded on videotape, and images were also captured with a digital medical device system. Respiration, heart rate, temperature, appetite, attitude, and postural positions were evaluated at 12, 24, 48, and 72 h after surgery. The 51 laparoscopic procedures provided 48 renal samples (approximately 100 mg each). The 1st and 2nd samples were from the right kidney, and the 3rd sample was from either the left or the right kidney; the 4th and 5th samples were from the left kidney. Adhesions made an approach from the right side difficult for the 3rd sample. No clinical changes were observed in 9 steers after the procedure. One steer died after the 3rd procedure owing to hemorrhage.