Common diseases - Chronic renal insufficiency
Renal insufficiency occurs when the renal function deteriorates to a point where the kidneys are unable to fulfill their functions to eliminate waste, maintain a water and electrolyte balance, and produce hormones. Generally, chronic renal insufficiency has been present for some time (months or years) when the diagnosis is made and the disease is irreversible. Dogs and cats with chronic renal insufficiency cannot be cured but in some cases their clinical signs can be controlled successfully.
Animals are born with such an abundance of renal cells that the signs of renal insufficiency only appear when more than 2/3 of the kidneys are already damaged. Because of this great reserve of renal cells, it is often difficult to diagnose chronic renal insufficiency at an early stage. Consequently, chronic renal insufficiency is a deceitful disease that declares itself just when the renal damage is already advanced.
Typically, the first signs of chronic renal insufficiency are an increased water consumption and an increased quantity of urine. Other signs are weight loss, a dull coat and an increasingly difficult appetite. As renal insufficiency progresses, the kidneys are unable to eliminate metabolic waste and clinical signs become worse: vomiting, loss of appetite, ulcers in the mouth area, halitosis, weakness and depression. Other consequences of chronic renal insufficiency are anemia and hypertension. Anemia can worsen the loss of appetite, weakness and depression. Hypertension can cause eye damage (sudden blindness), cerebrovascular accidents, and heart and kidney damage.
The diagnosis of renal insufficiency is confirmed with blood and urine analyses. Other diagnostic tests are sometimes necessary (X-rays, urinary culture, ultrasonography, measuring the arterial blood pressure, fundoscopic eye exam, etc.).
Fortunately, some animals that have renal insufficiency can be treated (not cured however) and have a good quality of life for months or years. Depending on the stage of renal insufficiency, many treatments can be useful for the affected animal: a diet change (low in protein, salt and phosphorus), fluidotherapy and some medications (antacids, anti-nausea, appetite stimulant, etc.).
With humans, chronic renal insufficiency can be controlled with dialysis (hemodialysis or peritoneal dialysis) or a renal transplant. With small animals, dialysis usefulness is limited because of the cost involved and the decrease in the quality of life that is associated with it. With some cats that have renal insufficiency, renal transplant is possible but very expensive. Renal transplant is reserved to cats for which the standard medical treatment does not work.