Cat & Dog - Early Renal Disease (ERD) - The Detection of Microalbuminuria

What is microalbuminuria?

Albumin is an important protein found in the bloodstream.  It is not normally present in the urine of healthy dogs and cats.  Microalbuminuria indicates the presence of minute quantities of albumin in the urine.  Until quite recently renal (kidney) diagnostic methods could only detect 'end stage' renal disease, when approximately 75% of functional kidney tissue (nephrons) had been destroyed.

With the development of more sensitive tests, minute quantities of albumin can now be detected in the urine.  This can, in some cases, be used as an early warning system for possible future kidney problems.

What are the problems that can result in microalbuminuria?

Many conditions lead to damage of nephrons (the microscopic filtration units of the kidneys). This results in the appearance of minute quantities of albumin in the urine.  The cause of this can be dental disease, chronic skin disease or bowel disease, as well as infectious diseases, (e.g. feline leukaemia virus, Ehrlichia infection, heartworm and Lyme disease).  Metabolic problems such as diabetes, hyperthyroidism, hypertension and certain cancers may also be implicated.

Is the ERD test complicated?

The test is based upon enzyme linked immuno absorbent assay, (ELISA) technology.  The test is relatively simple and can often be carried out at the practice.

What is required?

All that is needed is a small quantity of fresh urine.

If the test is positive does this mean my pet has progressive renal disease?

No, not necessarily.  A positive result is merely an early warning sign.  In the majority of cases management of the underlying health problem results in a resolution of the microalbuminuria.  In some cats and dogs however, the problem persists and the degree of microalbuminuria increases over time.  These are the animals that are at risk and they should be regularly monitored.

If the test is positive, what is the procedure?

We will discuss this with you fully.  Depending on the results further testing may be necessary to assess the underlying problem.  Alternatively, we may recommend regular check-ups every 3-6 months carrying out further ERD testing to check if the problem is worsening.  If so, underlying kidney disease is likely to be present and, although a complete cure is unlikely, early detection at least means that supportive treatment can commence and the progression of the disease can be delayed.