What is Chronic Kidney Disease (CKD) in Cats?

Chronic Kidney Disease (CKD) is the most common kidney disease affecting cats. It is a condition where the kidneys progressively lose their ability to function properly over time. CKD can affect 30-50% of cats over the age of 15, with both male and female cats being equally at risk.

While the exact cause of CKD in cats is unknown, certain pre-existing kidney or urinary tract conditions may predispose cats to developing this disease.

What Do the Kidneys Do for Cats?

The kidneys perform several essential functions for your cat, and when they lose function due to CKD, it affects multiple aspects of your cat’s health:

1. Filtering Waste: The kidneys filter and concentrate metabolic waste products from the blood. This waste is then excreted in urine. As kidney function declines, waste products build up in the bloodstream, and urine becomes more dilute.

2. Regulating Blood Pressure: The kidneys help maintain normal blood pressure. In CKD, your cat may develop high blood pressure (hypertension), which can lead to further complications.

3. Red Blood Cell Production: The kidneys play a role in producing red blood cells. When kidney function decreases, anemia (low red blood cell count) may develop.

4. Balancing Electrolytes: The kidneys regulate vital electrolytes, such as potassium, essential for normal cellular function.

Consequences of Chronic Kidney Disease in Cats

1. Dilute Urine and Increased Thirst

Cats with CKD produce large amounts of dilute urine, leading to dehydration if they cannot drink enough to compensate. They may also be at higher risk for urinary tract infections, which can cause pain and lead to litter box issues.

2. High Blood Pressure (Hypertension)

CKD can cause hypertension, leading to:

• Eye Problems: Sudden blindness or eye pain, which may be irreversible if not treated quickly.

• Brain Effects: Disorientation, balance issues, seizures, and behavior changes.

• Kidney Damage: High blood pressure can accelerate kidney damage, creating a vicious cycle that worsens CKD.

• Heart Disease: Increased demand on the heart due to hypertension can cause the heart walls to thicken, leading to abnormal heart rhythms.

3. Anemia

As kidney function declines, your cat may become anemic. Symptoms of anemia include fatigue, weakness, trouble breathing, and irregular heart function due to thinner blood.

Signs of Chronic Kidney Disease in Cats

Pet parents should watch for these symptoms of CKD in cats:

• Increased thirst and urination: Your cat may drink more and urinate frequently.

• Weight loss and poor appetite: Cats with CKD often lose weight, muscle mass, and their appetite.

• Lethargy: Cats may become more tired and less active.

• Vomiting and nausea: The buildup of toxins can make cats nauseous, causing vomiting and reduced appetite.

• Urinating outside the litter box: Cats with CKD may struggle with litter box habits, urinating just outside the box or in inappropriate places.

How is Chronic Kidney Disease Diagnosed in Cats?

Your veterinarian may recommend several diagnostic tests to confirm CKD and monitor its progression:

1. Blood Chemistry Panel: This test measures kidney function and tracks electrolyte levels. It provides crucial information on waste buildup and the overall health of other organs.

2. Complete Blood Count (CBC): This test measures red blood cells, white blood cells, and platelets. It helps identify anemia and any signs of inflammation or infection.

3. Urinalysis: This test analyzes your cat’s urine for protein concentration, infection, and the overall health of the urinary tract.

4. Blood Pressure Check: Monitoring your cat’s blood pressure helps identify hypertension, which can worsen CKD.

5. X-rays and Ultrasound: These imaging tests help visualize changes in kidney size and structure and rule out other potential issues.

Stages of CKD in Cats

The International Renal Interest Society (IRIS), an organization of veterinary kidney specialists, provides guidelines for staging CKD based on kidney values, urine protein concentration, and blood pressure. CKD is categorized into stages I-IV, with stage I being the least severe and stage IV the most advanced. Your vet will monitor your cat’s CKD stage over time to adjust treatments as necessary.

Treatment Options for Cats with CKD

While CKD is not curable, there are several ways to slow its progression and manage symptoms:

1. Prescription Diets: Therapeutic renal diets, specifically designed for CKD, are low in protein and phosphorus to reduce kidney stress while maintaining proper nutrition. Transition your cat slowly to avoid food aversion.

2. Hydration: Keeping your cat hydrated is crucial. In some cases, subcutaneous fluids can be administered at home to help with hydration, but it must be done carefully to avoid stress.

3. Potassium Supplements: Potassium is often lost through the kidneys in CKD, so supplements may be needed to maintain healthy levels.

4. Blood Pressure Medications: Hypertension caused by CKD can be managed with medications to protect the kidneys, heart, eyes, and brain.

5. Anemia Treatment: Anemia can be treated with medications or, in severe cases, blood transfusions. Discuss these options with your vet, as they can be costly and require close monitoring.

6. Appetite and Nausea Control: Medications like appetite stimulants, anti-nausea drugs, and antacids can help manage nausea and improve your cat’s appetite.

When Should You Consider Euthanasia for a Cat with CKD?

When managing CKD becomes too difficult, and your cat’s quality of life declines significantly, it may be time to consider humane euthanasia. Signs that it might be time include:

• Loss of appetite: When your cat stops eating entirely and stimulants are no longer effective.

• Severe vomiting: Persistent vomiting that cannot be controlled with medications.

• Extreme lethargy or weakness: When your cat can no longer enjoy daily activities or interact with you as they normally would.

• Difficulty with hydration or medications: If your cat resists treatments like subcutaneous fluids, or if administering medication becomes too stressful for both you and your cat.

Final Thoughts on Chronic Kidney Disease in Cats

As a pet parent, seeing your cat struggle with CKD is never easy. By understanding the disease, recognizing symptoms early, and working with your veterinarian to manage treatment, you can help improve your cat’s quality of life. Discuss any concerns about your cat’s condition with your veterinarian to make informed decisions about their care and comfort.

About Dr. Katie Suter

Dr. Katie Suter is an internship trained veterinarian with experience in emergency and general practice medicine. She received her Bachelor of Science at the University of New Hampshire in Animal Science and her Doctor of Veterinary Medicine degree at the University of Minnesota. She focused on at home pet end-of-life care in the Boston metro area before moving up to New Hampshire where she lives with her husband and two cats. Dr. Katie is licensed in New Hampshire, Vermont, and Massachusetts.  She is a member of the New Hampshire Veterinary Medical Association.

Dr. Katie is Fear Free Certified, an animal handling certification that reduces fear, anxiety, and stress in our pets. She is a member of the Feline Veterinary Medical Association and is a certified Cat Friendly Veterinarian through this organization.  She currently serves as a volunteer on the Cat Friendly Practice committee.

Dr. Katie is also a Certified Peaceful Euthanasia Veterinarian through The Companion Animal Euthanasia Training Academy Master Program.

Dr. Katie has achieved the accomplishment of a year-long process of becoming a Certified Hospice and Palliative Care Veterinarian through her membership with the International Association for Animal Hospice and Palliative Care.  This is a rigorous program for those that want to be on the forefront of end-of-life pet care.