What Are the Stages of Kidney Disease in Cats and How Is Each Treated?

Posted by Petdirect on 20th Nov 2024

Kidney disease is a common health issue in older cats, often developing gradually over time. Knowing the stage of kidney disease your cat is in can help you understand their health needs and enable you to provide the right treatment and care to manage their condition. This article explains how to identify the stage of kidney disease in your cat, specific symptoms to watch for, and the treatment options available at each stage.

What is Chronic Kidney Disease in Cats?

Chronic kidney disease (CKD) occurs when a cat’s kidneys gradually lose their ability to filter waste from the blood. It often develops slowly over years, with symptoms becoming more noticeable as kidney function declines. While CKD can’t be cured, early detection and appropriate management can help slow its progression, improve your cat’s quality of life, and prolong their lifespan.

Staging Kidney Disease in Cats

Veterinarians commonly use the International Renal Interest Society (IRIS) guidelines to stage CKD in cats. IRIS stages CKD in four stages, based on blood tests that measure creatinine and symmetric dimethylarginine (SDMA) levels, both indicators of kidney function. Other factors, including phosphorus levels, blood pressure, and proteinuria (protein in the urine), are also considered in staging, as they provide more information on the severity of the disease.

Stages of Kidney Disease in Cats

Stage 1 (Early-Stage CKD)

Description: This early stage shows minimal changes in kidney function, often with no visible symptoms.
Diagnosis: Creatinine levels may be on the high end of the normal range, but SDMA levels are often elevated earlier, indicating the kidneys are starting to struggle.
Symptoms: Cats may show very mild signs, such as increased thirst, but often appear quite healthy.

Stage 2 (Mild CKD)

Description: Kidney function continues to decline, but symptoms are still relatively mild.
Diagnosis: Creatinine, SDMA, and other test markers are above normal, although still below the levels seen in advanced stages. Blood pressure may begin to elevate.
Symptoms: Increased thirst and urination are more noticeable, though many cats remain energetic and appear otherwise healthy.

Stage 3 (Moderate CKD)

Description: Kidney function has significantly decreased, and symptoms become more evident.
Diagnosis: Blood tests show a clear reduction in kidney function with elevated creatinine and SDMA levels, and blood pressure may be high.
Symptoms: Symptoms like vomiting, weight loss, loss of appetite, and lethargy are common. Your cat may also appear dehydrated and have a dull coat.

Stage 4 (Severe CKD)

Description: This is the most advanced stage, where kidney function is severely impaired.
Diagnosis: Blood tests show high creatinine, SDMA, and BUN (Blood Urea Nitrogen) levels, with elevated phosphorus and other indicators of kidney failure.
Symptoms: Cats in Stage 4 often experience severe symptoms, including frequent vomiting, poor appetite, weight loss, severe lethargy, dehydration, and potentially anaemia.

Diagnosing the Stage of Kidney Disease in Your Cat

Determining the stage of kidney disease requires a visit to your veterinarian. The vet will conduct blood tests to measure creatinine, SDMA, BUN, and other important markers. Urinalysis will also be conducted to check for protein loss in the urine, which is another indicator of kidney disease. Regular monitoring through blood and urine tests is important, especially if your cat is at risk due to age, breed, or other health factors.

In addition to blood and urine tests, your vet may monitor your cat’s blood pressure and perform imaging tests to assess kidney size and structure, as changes in kidney size can sometimes indicate underlying issues contributing to CKD.

Treatment Options for Each Stage of Kidney Disease

Treatment for CKD in cats primarily focuses on managing symptoms, slowing disease progression, and supporting kidney function. Treatment plans will vary depending on the stage of the disease.

Stage 1: Early-Stage CKD Treatment

Diet: Your vet may recommend a kidney-friendly diet, which is low in protein and phosphorus to reduce the burden on the kidneys.
Hydration: Ensuring your cat stays hydrated is crucial. Encourage water intake, and consider using wet food to increase fluid intake.
Regular Monitoring: Regular blood and urine tests help monitor disease progression and allow for early intervention if the disease worsens.

Stage 2: Mild CKD Treatment

Specialised Diet: A therapeutic kidney diet is even more important at this stage, as it reduces kidney workload by lowering protein, phosphorus, and sodium.
Phosphorus Binders: If blood tests indicate elevated phosphorus levels, your vet may prescribe phosphorus binders to reduce absorption.
Blood Pressure Management: High blood pressure can damage the kidneys further, so your vet may recommend medications to control it.
Hydration Support: Encourage water intake, and consider giving your cat fluid injections (subcutaneous fluids) if recommended by your vet.

Stage 3: Moderate CKD Treatment

Fluid Therapy: Subcutaneous fluids may become part of your cat’s regular treatment to combat dehydration and help flush out toxins.
Medications: Your cat may need medications to control nausea, appetite stimulants, or anti-vomiting drugs, along with blood pressure management.
Dietary Supplements: Supplements to address deficiencies in potassium or vitamins may be recommended, as cats with CKD can struggle to retain essential nutrients.
Pain Management: Your vet may provide pain relief if your cat experiences discomfort or joint issues due to the impact of CKD on overall health.

Stage 4: Severe CKD Treatment

Intensive Fluid Therapy: At this stage, fluid therapy becomes essential. Your vet may recommend frequent or daily subcutaneous fluids to help flush out toxins and prevent dehydration.
Pain Management and Comfort Care: Your cat’s comfort is a priority. Pain management, anti-nausea medications, and medications to improve appetite can help your cat feel more comfortable.
Advanced Nutritional Support: An even more restricted protein diet and higher levels of supplements may be recommended to manage deficiencies.
End-of-Life Considerations: Some cats with Stage 4 CKD may not respond well to treatment, and quality of life can become a major factor. Discussing end-of-life care options with your vet can help ensure your cat remains comfortable.

Supporting a Cat with Kidney Disease at Home

Regardless of the stage, there are supportive steps you can take at home to help your cat feel more comfortable:

Encourage Fluid Intake: Providing fresh water, using a pet water fountain, or feeding wet food can help keep your cat hydrated.
Provide a Comfortable Environment: Keep your cat’s space clean, calm, and cosy. Cats with CKD may prefer warm, quiet areas where they can rest undisturbed.
Monitor for Changes: Keep an eye out for changes in appetite, weight, and behaviour, and report any concerns to your vet promptly.
Adhere to Medications and Appointments: Give medications as prescribed and attend regular veterinary check-ups to monitor your cat’s kidney health and adjust treatment as needed.

When to Contact Your Vet

If you notice any sudden worsening of symptoms—such as severe vomiting, loss of appetite, or sudden weight loss—it’s important to contact your vet. These could indicate your cat’s kidney disease has progressed, or they may need adjustments in their treatment plan.

Conclusion

While CKD is a serious condition, many cats can live comfortably with the disease when given proper care. By understanding the stages of kidney disease and working with your vet to provide appropriate treatment, you can help manage the condition and improve your cat’s quality of life. Regular veterinary check-ups, a supportive diet, and attentive care are key to ensuring your cat feels their best for as long as possible.