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Understanding Cat Kidney Disease

A cat looking at the camera

Kidney disease is a common condition in cats, particularly as they age. Known medically as renal failure, it can either develop suddenly (acute) or gradually (chronic), with chronic being more prevalent in older cats. 

The primary function of the kidneys is to filter natural waste products from the blood and excrete them via urine. When a cat’s kidneys begin to fail, these waste products accumulate in the bloodstream, leading to a decline in health. Chronic Kidney Disease (CKD) - also known as Chronic Renal Failure (CRF) -, is a prevalent issue in older cats, that occurs when the kidneys progressively lose their filtering ability over months or years. This gradual deterioration is often linked to the natural aging process, which wears down the kidney's structures and functions.

While the exact causes of CKD are not always identifiable, certain factors are known to contribute to the development of this condition:

  • Genetic Conditions - Breeds like Persians and British Shorthairs are predisposed to developing polycystic kidney disease, a genetic disorder where cysts form in the kidneys, impairing their function.

  • Infections - Both bacterial and viral infections can harm the kidneys. Conditions like Feline Immunodeficiency Virus (FIV) or bacterial infections in the urinary tract play a role in the onset of CKD.

  • Cancer - Although rare, cancerous growths in the kidneys can be a contributing factor to CKD.

  • Other concurrent diseases, such as heart failure, hyperthyroidism (overactive thyroid), and hypertension (high blood pressure) cause problems with blood flow to the kidneys, and are common causes of CKD.

CKD typically develops slowly and symptoms worsen gradually, which contrasts sharply with acute kidney disease that results from sudden, significant damage to the kidneys and presents severe symptoms quickly.

Early detection and appropriate management can greatly improve the quality of life for a cat with kidney disease. In this article, we delve into the essentials of cat kidney disease, providing insights into its causes, symptoms, and management strategies.


What is Cat Kidney Disease?

Cat kidney disease involves the loss of kidney function over time. The kidneys are vital organs that filter out toxins, balance electrolytes, and produce hormones. When they fail, harmful toxins build up in the bloodstream, leading to severe health complications. This disease is particularly insidious because symptoms typically appear only after significant loss of function. As the kidneys fail, they first lose the ability to concentrate their urine, putting them at risk of dehydration. Later in the course of the disease they also lose the ability to dilute their urine

Causes and Risk Factors

Several factors contribute to the onset of kidney disease in cats:

  • Age - Older cats are particularly susceptible.

  • Breed predispositions - Some breeds, such as Persians and Siamese, are genetically more prone to kidney problems.

  • Environmental factors - Exposure to certain chemicals or toxic substances can damage the kidneys.

  • Other health issues - Diseases such as diabetes, hyperthyroidism and high blood pressure complicate kidney function.

Signs and Symptoms to Watch For

Early recognition of cat kidney disease is crucial. Key symptoms include:

  • Increased thirst and urination

  • Weight loss and reduced appetite

  • Vomiting 

  • Diarrhoea or constipation

  • Dull coat and general poor appearance

  • Lethargy or reduced interest in usual activities

Diagnosis and Treatment Options

Diagnosing cat kidney disease typically involves a thorough evaluation by your veterinarian, which includes blood tests, urine tests, and blood pressure measurements. Imaging studies such as X-rays or ultrasounds may also be utilised to assess the health of the kidneys and detect any underlying causes of the kidney disease.

Annual health checks, including urine +/- blood tests in older cats, can help pick up kidney disease at early stages before any signs are seen.

Treatment of cat kidney disease aims to slow the progression of the condition and alleviate symptoms, since it's not possible to reverse the damage already done. Here's a comprehensive look at the treatment options:

  • Initial Stabilisation - Cats diagnosed with kidney disease often suffer from dehydration due to increased urine production. Vets may administer fluids intravenously to rehydrate your cat. Additionally, because the build-up of toxins can cause nausea and poor appetite, your cat may receive anti-sickness medications and appetite stimulants.

  • Blood Pressure Management - High blood pressure can be both a contributing factor, and a product of kidney disease and can exacerbate kidney damage. Medications to control blood pressure might be prescribed to prevent further deterioration of kidney function and other related health issues, such as vision problems.

  • Infection Control - Since cats with kidney disease are prone to urinary tract infections, antibiotics may be prescribed if there are signs of an infection.

Ongoing Management involves several key components:

  • Specialised Diet - Nutritional management plays a crucial role in supporting kidney function. Diets formulated for kidney health typically have reduced levels of protein, phosphorus, and sodium. Wet food formulations are preferred to increase fluid intake. Your vet can assist in selecting the most appropriate diet for your cat.

  • Enhanced Hydration - Encouraging your cat to drink more water is vital. Ensure freshwater is available at all times, and consider using pet water fountains to appeal to cats that prefer moving water. You should provide multiple sources of water throughout your home, taking note of any preferences your cat may have for the shape and material of the vessel. For example some cats like to drink from a very full tall glass, whereas others prefer a shallow ceramic saucer.

  • Phosphate Control - If phosphate levels in the blood are high, phosphate binders may be added to your cat's food to prevent dangerous accumulations.

  • Regular Veterinary Visits - Ongoing monitoring through regular veterinary check-ups is essential. These visits often include additional blood and urine tests to monitor the progression of kidney disease and adjust treatment as necessary.

  • Supplementation - Depending on your cat's specific needs, vitamin supplements may also be recommended to support overall health.

With close treatment and regular monitoring, cats with kidney disease can continue to live fulfilling lives for many months to years. However, it's important to regularly assess their quality of life as the disease progresses. When treatments no longer provide a benefit and your cat's comfort is compromised, it may be time to discuss more compassionate options, such as euthanasia.

When to Say Goodbye

Deciding when to say goodbye to a cat with kidney disease revolves around their quality of life. If you feel your cat’s quality of life is beginning to suffer, it’s time to think about your options, no matter how hard this may be.

Consult with your veterinarian about your cat's quality of life and consider palliative options when treatments no longer provide comfort. If you are in our service areas and want to book a palliative care or in-home euthanasia appointment with us, contact our team via 0800 049 5944 or request an appointment.


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