The kidneys’ function is to eliminate waste from the body – metabolic, pathologic and toxic waste. They concentrate urine to preserve fluid and maintain hydration. In addition to these fundamental functions, they maintain correct blood pressure, produce the hormone that triggers bone marrow production of red blood cells, and control body electrolytes at correct physiological levels. Failure of the kidneys has an impact on all of these functions.
Renal failure is a common condition in older cats. Feline kidneys are highly efficient at concentrating urine and are very hardworking organs. During a lifetime of eliminating wastes, toxins and infectious organisms, bouts of illness, fever and dehydration, they often start to show signs of wear and tear. This will first manifest as COMPENSATED RENAL INSUFFICIENCY – when the cat is well but the kidneys are producing more dilute urine than normal. Renal insufficiency will progress over time to CHRONIC RENAL FAILURE. Chronic renal failure is characterised by the animal producing very dilute urine, and drinking a lot of water to compensate for the resultant fluid losses. These cats start to lose weight as protein is leaked out through the kidneys. More advanced cases of renal failure will begin to show signs of URAEMIC SYNDROME as the other functions of the kidneys begin to fail. Uraemic syndrome is characterised by anaemia (causing weakness and lethargy), gastritis (causing vomiting), a build-up of toxins in the body and various blood electrolyte aberrations.
- Dirty teeth and mouth infections
- Frequent cat fight abscesses
- Severe dehydration (associated with illness or shock)
- Genetic predisposition to renal failure at a young age (congenital renal disease)
Early signs of trouble: More advanced illness:
- Increased drinking
- Extreme weight loss
- Weight loss
- Bad breath
- Lethargy and weakness
- Drooling and possibly bleeding from the mouth
- Disorientation, seizures and death
A simple, inexpensive, in-house urine test can be performed to assess your cat’s renal function by checking how concentrated the urine is. If the urine is found to be more dilute than it should be, then a full blood test will be recommended to check the levels of kidney enzymes, electrolytes and to check for anaemia.
The main therapy used to manage kidney failure in cats is diet therapy. The diet aims to do four things:
- Protein restriction
- Phosphate restriction
- Sodium restriction
- Supplementation with omega-3 fatty acids
Renal support or kidney diets are specially formulated prescription food to protect the kidneys, slow the production of renal toxins, help control blood electrolytes and maintain body weight.
The only definitive treatment for renal failure is a kidney transplant. Cat specialists in Brisbane are performing this procedure with increasing success, however only select individuals are medically suited. In most individuals, management of kidney failure is aimed at controlling the illnesses associated with uraemia syndrome (build up of renal toxins) and preserving remaining kidney function for as long as possible.
In addition, individuals may benefit from some of the following:
- Phosphate binders to help control electrolyte abnormalities
- Medication to reduce renal protein loss
- Medication to reduce high blood pressure
- Antibiotics for secondary bladder infections or concurrent kidney infections
- Vitamin B injections
- Antacids to treat gastritis and stomach ulceration
- Intravenous fluids at times of stress
- Medication to treat anaemia
We recommend regular in-house urine checks to assess how well your cat’s kidneys are concentrating urine, and to check for bladder infections. We may also recommend intermittent blood tests. In addition, we like to check your cat’s weight every 2-4 weeks, to check their hydration regularly, and they may require regular visits for Vitamin B injections.
When management is started early, cats can live for years with compensated renal insufficiency. Once chronic renal failure is established and uraemic syndrome has started, cats may die or require humane euthanasia within approximately six months, although this can be very variable.
If you have any questions regarding kidney failure in cats, please do not hesitate to call the clinic on 38991495.