It's so important to know the signs of CKD and to remember to get regular checkups for your furry friend!
Here is some great info from Cornell Feline Health Center.
According to Cornell Feline Health Center,
Chronic kidney disease (CKD) is the persistent loss of kidney function over time. Healthy kidneys perform many important functions, most notably filtering the blood and making urine, so problems with kidney function can result in a variety of health problems for a cat. Among the many different kidney diseases that may affect cats, CKD is the most common.
Clinical Signs
Cats with CKD may experience a buildup of the waste products and other compounds in the bloodstream that are normally removed or regulated by the kidneys. This accumulation may make them feel ill and appear lethargic, unkempt, and lose weight. They may also lose the ability to concentrate their urine appropriately, and as a result they may urinate greater volumes and drink more water to compensate. The loss of important proteins and vitamins in their urine may contribute to abnormal metabolism and loss of appetite. They may also experience elevated blood pressure (hypertension), which can affect the function of a number of important systems, including the eyes, brain, and heart.
Another cause of lethargy in cats with CKD is the buildup of acids in their blood. The kidneys of cats with CKD may not excrete these compounds appropriately, making affected cats prone to blood acidification, or acidosis, a condition that can significantly affect the function of a variety of organ systems in the body. CKD may also decrease a cat’s ability to produce red blood cells, which can lead to anemia, a reduced concentration of red blood cells in their blood. This may cause their gums to appear pale pink, or in severe cases, whitish in color, and may make them lethargic.
* Source: https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/chronic-kidney-disease
* Image source: Cornell Feline Health Center