What do the kidneys do? Why are they so important?
The kidneys have a number of functions in the body. The most important of these are;
- Maintaining balance of fluid and electrolytes in the body
- If the kidneys are not able to correctly balance fluid and electrolyte levels, animals with kidney disease may be dehydrated even though they are drinking large volumes of water.
- Filtering and flushing waste products from the blood into the urine
- When the kidneys are not able to ‘keep up’ with the demand, excess waste products build up in the blood stream. This can cause nausea and lethargy. We can measure these waste products in clinic with a simple blood test, which can give us an indication of the degree of kidney disease.
- Produce certain hormones, the main one controls red blood cell production
- If the kidneys are not telling the body to make new blood cells when required, anaemia can develop and this can cause weakness and lethargy.
Chronic kidney or renal disease (chronic means the symptoms develop slowly) is one of the most common diseases in our senior pets, especially cats. If chronic kidney disease is picked up early, treatment and diet changes can slow down the progression of the disease.
How do I know if my dog or cat might have kidney disease?
Dogs and cats with kidney disease can show one or all of the following;
- Drinking more water
- Urinate more frequently or large amounts
- Lethargic, or not as active
- Not as interested in food
- Weight loss
- Vomiting
- Dehydration
- Bad breath and mouth ulcers
If you notice any or all of the above signs get your pet to the vet as soon as possible. The vet will perform a full physical examination and will need to run a blood and urine test. Physical examination often does not show more than dehydration. In house blood testing is very useful to check levels of urea, creatinine and phosphorus (waste products that the kidneys excrete), red blood cell count (anaemia), and electrolyte levels (sodium, potassium and chloride). There is also a new blood test, processed at the laboratory, measuring levels of symmetric dimethylarginine (SDMA) that helps to detect kidney disease much earlier than previous tests. Urine testing is valuable to be able to grade kidney disease, i.e. work out how bad your pets kidneys are. The kidneys are in control of concentrating the urine (taking the water out). When the kidneys are starting to fail, we can detect this be measuring the concentration of a urine sample in a very quick and easy test. A urine test can also help us to rule out diabetes or urinary tract infections. Damaged kidneys will also leak protein into the urine. This can be detected in an easy in house test, but needs to be sent to the lab to be able to measure the degree of kidney disease.
Regular check ups (we recommend 6 monthly) with your veterinarian once your pet is over the age of 7 is strongly recommended. Our veterinarians are trained to pick up problems long before they start to become apparent in your pet.
What can be done about kidney disease or failure?
Unfortunately chronic kidney disease is a progressive condition, there is no cure, but we can try and slow down the deterioration.
Short term treatment of the disease is aimed at correcting the dehydration and altered electrolyte levels and attempting to “flush” the toxins from the body. This is often done with intravenous fluids while being hospitalised.
Extensive research has shown that specialised diets, controlling the type and level of protein, phosphorus levels and a number of other features, can reduce the amount of work the kidneys have to do. They do this by reducing the level of toxins that the kidneys are responsible for flushing out through the urine.
Different medications can be used to reduce nausea, reduce blood pressure or increase the blood flow through the kidneys to aid their function. All of these options will improve the patient’s quality and length of life.
The vet will assess each case individually and tailor the treatment to suit both patient and owner. Regular rechecks will be recommended to assess the animal’s progress.
