Polycystic kidney disease (PKD) is an inherited, slow progressing, congenital but a rather rare disorder in dogs which is characterized by formation of cysts of various sizes within kidneys. In this condition, large portions of renal parenchyma, the functional tissue of the kidneys which are normally differentiated, are displaced by multiple cysts. Cysts are air or fluid or semi-solid filled sacs that develop in pre-existing nephrons — the functional filtering cells of the kidney tissue — and in the collecting ducts. Cysts slowly grow and replace normal kidney tissue, causing the kidney to enlarge. These cysts replace the normal kidney tissue, while kidney function continuously declines, ultimately leading to kidney failure.
This is a congenital problem that is present at birth. This irreversible condition is not immediately life-threatening but if left untreated, it can lead to cyst progression and development of secondary bacterial infection, either of which may lead to sepsis, the presence of pus-forming toxic organisms in the blood.
Though this condition can occur in any dog, some breeds are predisposed including cairne terriers and beagles.
Though the condition is present from the time of birth, the affected dogs remain asymptomatic during their puppyhood. The signs only begin to appear as the dog grows older. The symptoms are non-specific. Most symptoms seen in dogs mimic renal failure from any cause. These include
loss of appetite
excessively drinking water
abdominal palpitation and involuntary muscle twitching