• Also known as polycystic kidney.
  • Can be seen in many different species.
  • Can have a hereditary basis.
  • The cysts may be single or multiple.
  • Results from the failure of development of the tubular system in nephrons.
  • Severely affected animals may die of renal failure early in life.
    • The affected kidney does not have enough functional reserve, and so small infections can have a serious effect on renal function.


  • Among the most commonly encountered malformations of the kidney.
  • Can be congenital or acquired.
    • Congenital cysts are common incidental findings in both pigs and calves. Simple cysts generally cause no problems verses polycystic kidneys which can disrupt the renal architecture and lead to compromised function. Persian cats and Cairn terriers are predisposed.
      • Kidney nephrons and collecting ducts have different embryological origins.
      • If their connection fails to develop during development, polycycstic disease may result (especially common in cats).
    • Acquired cysts can occur as a sequel to chronic renal disease involving interstitial fibrosis.