5.1 UPPER URINARY TRACT: AGE-RELATED CHANGES 5.1 UPPER URINARY TRACT: AGE-RELATED CHANGES

The following changes have been reported to occur with advancing age (after Mosier 1988 and Breitschwerdt 1988):

Compensated renal failure is present in many older animals. In one recent survey of 13 apparently healthy cats aged over 7 years of age all of them were found to have blood creatinine with /or without increased urea concentrations above the published normal range (Barber, P.1995 percommunication), and in another survey of 1600 dogs aged over 5 years 22.4% were found to have evidence of azotaemia (Leibetseder & Neufeld, 1991). Recent studies at the Royal Veterinary College, Uniof London have been unable to detect an age-related decrease in GFR using non-invasive radioactive technetium.

Early detection of the presence of renal failure is desirable to facilitate early intervention in an attempt to delay or stop progression and also to identify individuals in which renal excretion of drugs may be impaired, and those at risk of developing acute renal failure if stressed by the adminisof some drugs, e.g. non-steroidal anti-inflammatory drugs (NSAIDs), some antibiotics or the administration of a general anaesthetic.