Kidney disease, also known as renal disease, is commonly seen in older dogs. As the kidney ages, the filtering system, or glomeruli, becomes damaged or blocked. The glomeruli cannot regenerate once they are destroyed. A breakdown in the filtration system causes abnormalities in acid levels, salt content and blood pressure. Additionally, two byproducts of metabolized protein increase within the bloodstream. These byproducts are creatine and urea. A veterinarian can perform tests to establish blood levels.
Canine kidney disease has many causes. Destruction of kidney cells is a common repercussion of age. Viral, bacterial or fungal infections as well as cancer can cause kidney failure. Chronic interstitial nephritis (inflammation), trauma, or a toxic reaction to medications or poisons can cause kidney damage. Autoimmune diseases, amyloidosis, and congenital and inherited disorders may negatively affect kidney function as well.
Dogs may express a variety of signs that may mimic other diseases. Increased water consumption and an increased amount of urination is typical, but decreased urination, lack of urination, blood in the urine or inability to hold urine through the night may signify kidney problems. Vomiting, weight loss, lethargy, diarrhea, poor hair coat and a hunched over posture may also accompany kidney disease. Dogs may no longer eat during advanced stages of sickness and water intake decreases as well.
Test are performed to indicate the level of damage and subsequent treatment procedures. Urine specific gravity tests determine the concentration level of the urine. Lower specific gravity means less concentration and a more serious condition. Blood proteins leaked into the urine by failing kidneys are detected by urine protein content analysis. A microscopic examination differentiates between acute and chronic kidney disease. Blood urea nitrogen (BUN) tests detect the rise of urea nitrogen within the blood. Testing for creatine, however, is a more accurate test because creatine levels fluctuate less than urea nitrogen. Because failing kidneys are unable to sufficiently excrete phosphorus into the urine, testing for excessive blood phosphorus may be performed.
Restart and flush the kidneys by administering large amounts of fluid intravenously. This type of treatment is referred to as diuresis or fluid therapy. Diuresis aids in stimulating normal kidney cell function. Fluid therapy also replaces lost potassium and other electrolytes. Diuresis helps restore metabolic balance by flushing the system of nitrogenous waste. Phosphorus binders such as aluminum hydroxide may be used to decrease blood phosphorus levels. Reduce blood pressure by using angiotensin converting enzyme (ACE) inhibitors. Elevated blood pressure leads to further destruction of the glomeruli. ACE inhibitors decrease blood pressure by enlarging the diameter of the blood vessels. This minimizes destruction of the remaining functioning glomeruli.
Kidney damage is irreversible. Implemented treatments can slow the progression of the disease, prevent further damage or aid the kidneys in the filtration process. Test results performed by a licensed professional will indicate the level of disease and treatment protocol. To speed relief and prevent further damage, implementation of several treatments may be recommended and ongoing.