Chronic kidney disease in cats is unfortunately very common, affecting cats of all ages but especially the elderly. It is estimated that one in five cats over 13-15 years of age is affected, which is three times more frequent than in dogs, and the clinical condition tends to become increasingly chronic with the passage of time.
The older the cat, the greater the risk, and, unfortunately, an early diagnosis is very difficult to make as symptoms generally occur when more than 75% of the kidney has been irreversibly compromised. This makes regular check-ups at the vet absolutely essential, especially with elderly cats, in order to have an early diagnosis, and the best chance of fighting and treating the disease. Medical support and prompt treatment can slow the development of the disease, and consequently improve both the quality of life and animal lifespan.
The causes of kidney failure in cats
The disease is characterised by a reduced ability of the kidney to filter. The loss of this normal filtering capacity prevents waste products from being removed from the blood. Why this happens is largely unknown. Some predisposing factors for the disease have been identified, such as PKD, polycystic kidney disease (a hereditary disease among Persian cats), certain kidney tumours, systemic infections which involve the kidneys, as well as toxins, poisoning and genetic diseases. There is a good chance of slowing down the disease and allowing the animal a normal life when a cause can be diagnosed prematurely and treated. However, in most cases, chronic kidney failure is an insidious, slow-onset and progressive disease with few specific clinical signs.
Symptoms and diagnosis of kidney disease
Increased thirst associated with increased urine production are, generally speaking, early indications of the disease. Other symptoms develop as the disease progresses, such as vomiting, and behavioural changes including aggressiveness and apathy, followed by symptoms that should immediately alarm the owner such as exhaustion, dehydration and halitosis.
Diagnosis can be carried out by assessing clinical signs and performing laboratory tests, e.g. thorough blood and urine tests, blood pressure measurements, and other associated tests, including ultrasound. Cats with chronic kidney failure generally show higher levels of urea, creatinine and phosphorous. They have an impaired capacity to concentrate their urine and appear anaemic.
Treating kidney disease correctly
There is unfortunately no current cure for chronic kidney failure and so therapeutic treatment aims to slow the progression of the disease as much as possible.
Therapies are based around administering medicine and a diet that is relatively low in protein, phosphorous and sodium, and high in potassium. Essential fatty acids can help reduce kidney pressure and Camellia Sinensis supplements can help reduce inflammation and uremic toxins. Green tea polyphenols have also been scientifically shown to perform antioxidant activity and neutralise free radicals, limiting cellular stress on the kidneys by reducing the production of uremic toxins. Green tea polyphenols also help stimulate glomerular filtration and urine production.
It is also important to look out for associated diseases, such as urinary tract infections, which can greatly aggravate symptoms. Diet control can help ensure additional water content and so wet foods are preferable, or alternatively, a mixed wet-dry diet.