The First Report of Clinical and Pathological Studies of Polycystic Kidney Disease in a Herrik Lamb in the Middle East

Abstract

In April 2012, a 1-week-old female lamb was presented for evaluation to the field service at the Teaching Hospital Center, University of Urmia School of Veterinary Medicine with a history of progressive bilateral abdominal distention since birth. Two days after birth, the animal had mental dullness, a poor growth rate comparable to a twin, and progressive bilateral abdominal distension. On physical examination, the animal was in poor body condition and had a mass palpable in the cranial ventral abdomen (The abdomen was tight, round, and painful on palpation) and also lamb was bright, low awareness and responsive. Temperature (37°C), pulse (154 beats per minute), and respiration (55 breaths per minute) and weighing 3.5 kg were elevated. Histopathological examinations revealed that bilaterally enlarged kidneys were characterized by renal tubules at all levels of the nephron unit and extended into the cranial ventral abdomen. Glomeruli were sporadic, small and often hypoplastic or atrophic, located within a dilated Bowman’s capsule. Renal cysts were usually bilateral, occurred in cortex and medulla and varied from less than 0.5 mm to over 5 mm in diameter. Cysts were lined by epithelial cells of nephron origin. Macroscopic and microscopic studies were similar to autosomal recessive polycystic kidney disease in humans and to previous reports of juvenile polycystic disorders in several animal species. Consequently, a polycystic kidney disease was diagnosed in Herrik lamb.