Chronic Renal Failure in Dogs
Nine in every 1,000 dogs that are examined suffer from chronic renal disease. And while dogs of any age can be diagnosed with the kidney disease, it is more commonly seen in older dogs.
Failure of the kidney -- which among other things regulates blood pressure, blood sugar, blood volume, water composition in the blood, and pH levels, and produces red blood cells and certain hormones -- can take so place so slowly, that by the time the symptoms have become obvious, it may be too late to treat the condition effectively. Often, the kidney will find ways to compensate as it loses functionality over the course of months, or even years.
While chronic renal failure cannot be reversed or cured, treatment and management aimed at reducing the contributing factors and symptoms can slow its progression.
Chronic renal failure can affect both dogs and cats. If you would like to learn more about how this disease affects cats, please visit this page in the PetMD health library.
Symptoms and Types
Symptoms often occur gradually over an extended petriod of time. In addition, symptoms may vary and not all of those listed below will be seen in every dog:
- Vomiting
- Lethargy
- Diarrhea
- Constipation
- Depression
- Weight loss
- Increased thirst
- Lack of appetite (anorexia)
- Acute blindness
- Seizures and comas
- Blood in the urine (hematuria)
- An increase in the frequency and amount of urination
Causes
Causes of kidney failure can include kidney disease, urinary blockage (obstruction of the urinary tract or of the ureters), certain prescription medications, lymphoma, diabetes mellitus, and genetic (hereditary) factors.
The following breeds are prone to chronic renal failure:
Diagnosis
Your dog will undergo a complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis. Dogs with chronic renal failure may have anemia, abnormal electrolyte levels, and elevated blood pressure. The levels of certain protein enzymes and chemicals such as creatinine and blood urea nitrogen (BUN) will also be high.
Another good indicator of chronic renal failure is urine that is neither concentrated or dilute, thus indicating the kidney's inability to process the urine correctly. X-ray or ultrasound imaging may also be used to observe the size and shape of the dog's kidney(s) to see if there are any visibly noticeable abnormalities. Often, chronic renal failure causes kidneys to become abnormally small.
Treatment
Dogs suffering from long-term kidney failure will often undergo fluid therapy to assist with depleted body fluid levels (dehydration). Dietary protein is sometimes restricted, since it can further compound the problem.
Although there is no cure for chronic renal failure, there are numerous steps that can be taken to minimize the symptoms and slow the progression of the disease. For instance, feeding your dog a specially formulated kidney diet, or other diet low in protein, phosphorus, calcium, and sodium, is usually very helpful. These specially formulated foods will usually have a higher level of potassium and polyunsaturated fatty acids (omega 6 and omega 3 fatty acids), both have shown to be beneficial to the kidneys. The downside is that these foods are not flavorful.
If your dog is resistant to its new diet, small amounts of tuna juice, chicken stock, or other flavor enhancers can be used with guidance from your veterinarian.
Maintaining hydration is critical. You will need to ensure your dog always has an adequate amount of clean water to drink. If your dog has been diagnosed with dehydration, supplemental fluids may be given intravenously or under the skin (subcutaneously).
Phosphorus binders and vitamin D supplements are often given to dogs with chronic renal failure in an attempt to improve calcium and phosphorus balance, and to reduce some of the secondary effects of renal failure. H-2 receptor blockers, or other medications to treat the secondary gastric ulcers and gastritis that develops, can be helpful in increasing a dog's appetite. Depending on the symptoms and conditions, other medications that may be considered include:
- Anti-hypertensives to decrease blood pressure
- Enalapril to block angiotensin, a natural blood pressure elevator
- Erythropoietin to stimulate the production of red blood cells, thus increasing oxygen in the tissues
Living and Management
Chronic renal failure is a progressive disease. Dogs experiencing this disease should be monitored on an ongoing basis, with frequent check-ups to ensure that it is not necessary to make changes to medications or diet.
Your dog's prognosis will depend on the severity of the disease and its stages of progression, but a few months, or a few years of stability may be expected, with the proper treatment. The best way to manage this disease is to follow through with the treatments your veterinarian prescribes.
Pet owners are advised not to breed dogs that have developed chronic kidney disease.
Prevention
There are currently no known methods for preventing kidney disease.