24/05/2026
SENIOR PETS: KIDNEY DISEASE
Chronic kidney disease is one of the most common conditions affecting older cats. It occurs when there are long standing, irreversible changes to the kidneys that impair their ability to filter and remove waste products from the blood.
Chronic kidney disease can occur in cats of any age, but is most commonly seen in middle to older cats.
WHAT CAUSES CHRONIC KIDNEY DISEASE?
In most cases of chronic kidney disease, the exact cause is unknown. There are, however, some well recognised causes of chronic kidney disease, including:
- Idiopathic/age related - most kidney disease is considered age appropriate in senior cats, this is very normal in most cats 12 years and older.
- Kidney stones (uroliths) - Stones can form in the kidney and move into the ureter (connection between the kidney and bladder), resulting in obstruction of urine flow and acute kidney compromise. Left untreated , this can result in chronic loss of kidney function.
- Polycystic kidney disease - an inherited condition seen mainly in Persians and related breeds, where normal kidney tissue is replaced by multiple fluid filled cysts that develop within the kidneys.
Kidney infections - infection of the kidney may occur as an extension of bladder infections and can lead to damage to kidneys
- Toxins - such as Lilies (all parts of the plant including pollen) and certain drugs (anti inflammatories), can cause damage to the kidneys
- Kidney tumours - for example Lymphoma, can affect the kidneys and cause renal failure.
Kidney disease may also develop secondary to other diseases, such as cardiac disease, dental disease and high blood pressure.
WHAT ARE THE CLINICAL SIGNS OF CHRONIC KIDNEY DISEASE?
Cats usually show no signs of disease until 75% of their kidney function is gone. This means that when your cat shows obvious signs of the disease, it could already be in the advanced stages. Excessive thirst and increased urination are the main signs, however, there are other diseases that share these same symptoms. Other signs include:
- Increased thirst and/or urination
- Reduced appetite and weight loss
- Poor hair coat
- Dehydration
- Constipation
- Lethargy or weakness
Other signs may include vomiting, bad smelling breath and ulceration in the mouth.
MONITORING AND PROGNOSIS
Most cats require regular monitoring to monitor progression and assist in management of their kidney disease. This may involve repeat blood and urine tests every 3 -6 months, depending on the severity and rate of progression of kidney disease.
Kidney cells that have been damaged cannot be repaired. However, progression can be slowed down with appropriate treatment. This can improve the cat’s well being and significantly extend their lifespan.
CAN RENAL FAILURE BE PREVENTED?
The risks associated with chronic renal failure can be minimised by maintaining good hydration and a high quality diet. While maintaining good hydration, it is important not to force your pet to drink excessively. Many good filtering and flowing water bowls are available that can help encourage good hydration. Once kidney disease is diagnosed, specific diets can help support the kidneys in maintaining good function. The key is early diagnosis, so make sure your pet has regular screening tests. It is important to become familiar with what is and isn’t normal for your cat.
HOW IS CHRONIC KIDNEY DISEASE MANAGED?
Some cats may require initial hospitalisation and fluid therapy to correct dehydration and improve their appetite. Once stable, treatment iss aimed at supporting kidney function and minimising the complications of kidney disease.
Diet - the kidneys filter waste products from the blood, and most of these waste products come from the food your cat eats. Therefore, the workload of the kidneys can be significantly reduced by the type of food you feed your cat. Special prescription diets are low in phosphorus and protein and high in potassium to make feeding your cat easier. They are available in dry or wet forms. these food should be fed exclusively, with no extras given.
Antibiotics - it is relatively common for cats with renal failure to get urinary tract infections as their urine is less concentrated and mor habitable to bacteria.
Fluid Therapy - the patient should be encouraged to take in as much water as possible through wet food, and water fountains. If this is not sufficient, intravenous fluids can be used