Renal disease


What is renal disease?

Renal disease refers to any condition that damages and/or impairs the function of the kidneys. Usually, this damage is irreversible. Kidneys have three main functions:

To filter the blood and remove toxic wastes from the body in urine.
To conserve water within the body by concentrating urine appropriately
To produce important hormones such as erythropoietin, which stimulates red blood cell production.

Usually, it is not until about two-thirds of the kidney has become non-functional that we start to see clinical signs of disease.

What causes renal disease?

There are many causes of kidney disease, including inherited defects, infections, toxic substances and nutritional factors. Urinary obstruction can damage the kidneys and some cancers can also affect the kidneys. Renal disease can also be secondary to other problems within the body, for example cardiac disease, dental disease and hypertension (high blood pressure). Often we don't know the exact cause of renal disease - in these cases we provide supportive treatment.

What are the signs of renal disease?

A cat or dog with renal disease may show one or more of the following signs:

  • Increased drinking and urinating
  • Lethargy, weakness
  • Vomiting, diarrhoea
  • Acetone-scented breath
  • Mouth ulcers

How is renal disease diagnosed?

If we suspect renal disease, we will generally recommend urine analysis as the first step. If the urine is well concentrated, that rules out renal disease and we need to consider other causes for the clinical signs. If it is poorly concentrated, we need to perform full blood tests to confirm renal disease. We look mainly at the levels of three chemicals in the blood. These are chemicals that are normally excreted in urine. In animals with kidney disease, they are not filtered properly and instead build up in the blood. These chemicals are toxic in high levels and are responsible for your pet feeling unwell.

How is renal disease treated?

The most important part of the treatment of renal disease is a change in diet. By feeding a diet specifically formulated to support the kidneys, such as Royal Canin Renal or Hill's k/d, you will prolong your pet's life by a factor of two to three. Depending on the severity of renal disease, we may also prescribe anti-nausea medications and gut protectant drugs as symptomatic therapy. Other drugs are chosen on a case-by-case basis, depending on whether renal disease is causing hypertension (high blood pressure), proteinuria (protein in the urine) or other abnormalities.