Polycystic Kidneys
Polycystic kidneys refers to the development of fluid filled cysts that displace the normal kidney parenchyma (tissue). It is an inherited condition that usually affects both kidneys. Persian and other long-haired breeds have an increased incidence of the disease.

Often there are no obvious clinical signs until the cysts become large enough to cause renal (kidney) failure or abdominal enlargement (bloated appearance). There may be pain associated with large cysts which are pushing onto other adjacent organs within the body, however the cysts themselves are normally not painful unless they become infected. Abdominal palpation (examination by hand) may reveal lumpy kidneys in some cases. Ultrasound examination is the most useful diagnostic tool and is also used to screen cats before they are used for breeding. If the cysts eventually cause renal failure further signs will become noticeable,including excessive drinking, dehydration, weight loss, vomiting and depression. Cyst fluid may be aspirated (removed) with a needle where there is a suspicion of infection as these infections are usually not able to be detected in urine samples

There is no specific treatment for this condition. The management options available will vary between individuals. Most therapies are aimed at minimizing the effects of renal failure. In some cases with a limited number of large cysts it may be feasible to aspirate the fluid to relieve discomfort but to be effective this procedure will need to be performed every 1-2 weeks. In some cases where an infection in the cysts has led to sepsis (blood poisoning) it may be possible to perform a nephrotomy (surgical removal of a kidney) of one kidney.

Cats with this condition need to be monitored every 2-6 months to assess for the development of renal failure, infections and pain. The prognosis is good in the short term so long as there is no infection present, but long-term prognosis depends on the rate at which the cysts develop. Affected animals should not be bred.