Chronic Kidney Disease and Its Complications

OVERVIEW

Chronic kidney disease (CKD) is defined as a progressive irreversible deterioration of kidney function or structure in one or both kidneys that has been continuously present for 2 months or longer.

Among the many different kidney diseases that may affect cats, CKD is the most common. The prevalence of feline CKD increases with age.

Healthy kidneys perform crucial functions, such as filtering the blood, regulating blood pressure and making urine, so problems with kidney function can result in a variety of major health problems for a cat.

CKD is a disease for which there is no cure, only the ability to slow it down and manage the other symptoms. Ultimately, it’s fatal. But there is also good news: with early and proper care and treatment, many cats who are diagnosed with kidney disease can do well for up to several years after diagnosis.

SIGNS OF CKD

Signs of CKD, which are usually vague and only evident later on, may manifest due to the accumulation of toxins in the blood or because the body is trying to adapt to the challenging condition. They may include weight loss,inappetence, lethargy, polydipsia (increased thirst) and polyuria (increased urination, which leads to dehydration).

In most cases, chronic kidney disease (CKD) in cats comes with several complications that reduce quality of life and lifespan.

COMPLICATIONS OF CKD

The following complications are often associated with the progression of chronic kidney disease (CKD) in cats:

• Weight loss
• Dehydration
• Constipation
• Hypertension: High blood pressure
• Proteinuria: Excess protein in the urine
• Hypokalemia: Deficiency of potassium in the bloodstream
• Hyperphosphatemia: Higher-than-normal levels phosphate in the blood
• Urinary tract infections (UTIs): An infection of the kidney, ureter, bladder or urethra
• Anemia: Deficiency of red cells in the blood, resulting in pale appearance and fatigue
• CKD-associated mineral bone disorder
• Acidosis: Too much acid in the body

Although there is no definitive cure for CKD, treatment can improve and prolong the lives of cats with this disease. Therapy is geared toward minimizing the buildup of toxic waste products in the bloodstream, maintaining adequate hydration, addressing disturbances in electrolyte concentration, supporting appropriate nutrition, controlling blood pressure, and slowing the progression of kidney disease.

Because of possible complications that may arise, it’s crucial to monitor the clinical signs and overall condition of a cat with CKD. It’s also possible for cats with CKD to suffer from more than one condition*.

Managing inappetence, for example, is essential as it may lead to dehydration, anemia, hypokalemia and acidosis –which all typically make the condition worse.

Also, if an underlying cause has been identified, it needs to be treated to try and slow the progression of ongoing and irreversible damage to the kidneys.

*Comorbidity: The presence of one or more additional diseases or disorders co-occurring with a primary disease.

TESTS USED TO DISCOVER AND MONITOR COMPLICATIONS

• Urinalysis
• Blood tests
• Ultrasound
• Biopsies
• X-rays

TESTS FOR CHRONIC KIDNEY DISEASE

If your cat has symptoms of CKD, your veterinarian may recommend some or all of the following tests to determine whether treatment is needed.

Blood Testing

• Blood urea nitrogen (BUN)
• Creatinine
• Electrolytes (including sodium and potassium),
• Red blood cell count
• Protein concentrations

Urinalysis

• Concentration
• pH balance
• Protein concentration
• Presence of red blood cells
• Presence of other cells
• Urine culture for bacteria

 Other tests

• Abdominal ultrasound
• Radiographs (X-rays)
• Microscopic evaluation of biopsy samples
• Blood pressure

MORE ABOUT ANEMIA

As mentioned above, anemia refers to the deficiency of red cells in the blood.

Slowly progressive, mild to moderate, non-regenerative anemia may arise in cats with advanced CKD.

This complication, in turn, can contribute to inactivity and reduced wellbeing. Fortunately, quality and duration of life can be improved if and with proper management.

Causes of anemia include uremia. Uremia is characterized by a raised level in the blood of urea and other nitrogenous waste compounds that are normally eliminated by the kidneys.

DID YOU KNOW
Hematology is the branch of medicine involving study and treatment of the blood.

MORE ABOUT UTIS

Urinary tract infections (UTIs) can lead to lower urinary tract discomfort, urinary incontinence, abnormal urine odour, inappropriate urination and/or hematuria (blood in urine).

MORE ABOUT WEIGHT LOSS

Weight loss in cats with CKD can be caused by poor appetite or loss of muscle mass. This is problematic, so as soon as a cat appears underweight, the situation needs to be addressed. Depending on the cause, antinausea and appetite stimulant medications may help. Ensuring that enough protein and calories are consumed is also important, especially if a protein-restricted diet is given, which is usually the case. 

TREATING CKD IN CATS

With CKD in cats, treatment is aimed at supporting kidney function and minimizing the complications of CKD. To ensure optimal management of CKD, repeated investigations at regular intervals are necessary.

Treatment is usually symptomatic and supportive. Plus, it’s not uncommon to administer multiple drug therapies for cats with CKD.

One type of drug, for example, is used to help reduce the amount of protein lost in a cat’s urine, because losing too much protein in the urine is associated with a shorter life expectancy in cats suffering from CKD.