Kidney disease, also known as renal insufficiency, is a condition in which the kidneys are not functioning at full capacity. It is common that this condition will eventually lead to kidney failure. The kidneys are responsible for many things. The primary responsibility is to filter the blood of all toxins, reabsorb things such as water, sugar, and protein. Another responsibility of the kidneys is to signal the bone marrow to produce more red blood cells.
Clinical signs of kidney disease include excessive drinking and urinating, weight loss, vomiting, and loss of appetite. As the kidneys lose its abilities to filter the blood, toxins will begin to build up in the body leading to a condition known as uremia. Anemia sets in once the kidneys can no longer communicate with the bone marrow to produce red blood cells.
Diagnosis of kidney disease is accomplished with blood and urine tests. The most important values in the blood are BUN (blood urea nitrogen) and Creatinine. The BUN are metabolic waste products that increase once the kidneys are damaged. This is about the earliest indicator for kidney disease. However, it is not very specific for the kidney. Other things such as dehydration will elevate this value. The creatinine is a very specific kidney value but unfortunately is not an early indicator. The kidney function must decrease by 75% before the creatinine value increases. A urinalysis is also beneficial to quantify the ability of the kidneys to concentrate urine as well as see the level of protein loss.
Treatment includes fluid therapy and dietary management (low protein diet). Keeping the pet hydrated and fed is paramount. Other medications such as Benazepril has been shown to decrease the amount of protein lost through the kidneys. Azodyl is an enteric bacteria that has been shown to decrease BUN. Rarely blood transfusions are needed. Ideally, dialysis would clean the blood, but veterinary medicine is limited in this ability.