Kidney disease is very common in cats, but it also occurs in dogs. While dogs of any age can be diagnosed with kidney disease, it is more commonly seen in older dogs.
Kidney failure in dogs—among other things—contributes to regulation of blood pressure, blood sugar, blood volume, water composition in the blood, pH levels and the production of certain important hormones.
It can take place so slowly that by the time the symptoms of dog kidney failure are obvious, it may be too late to treat the condition effectively. The kidneys may lose functionality over the course of months, or even years, so active early monitoring can make a big difference for your dog’s health.
While chronic renal failure in dogs cannot be reversed or cured, treatment and management aimed at reducing the contributing factors and symptoms can slow its progression and effect on your dog’s well-being.
Symptoms of Kidney Failure in Dogs
Symptoms often occur gradually over an extended period of time. In addition, symptoms may vary, and not all of those listed below will be seen in every dog:
Lack of appetite (anorexia)
Seizures and comas
Blood in the urine (hematuria)
Causes of Kidney Failure in Dogs
Causes of kidney failure in dogs can include kidney disease, cancer, diabetes mellitus and genetic (hereditary) factors. Some breeds, including Bull Terriers and English Cocker Spaniels, have a higher risk of kidney disease. Acute kidney failure can be caused by urinary blockage (obstruction of the urinary tract or of the ureters), certain prescription pet medications, toxins and infections.
Diagnosis of Kidney Failure in Dogs
Your dog will undergo a complete blood profile, including a chemical blood profile, a complete blood count and a urinalysis, along with blood pressure testing. 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. Recently, a biomarker known as SDMA has become available to offer earlier detection of changes in kidney function.
Another good indicator of chronic renal failure is urine that is 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 for Kidney Failure in Dogs
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.
Dogs suffering from long-term kidney failure will often undergo fluid therapy to assist with depleted body fluid levels (dehydration). Maintaining hydration is critical. You will need to ensure that 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 and sodium restriction are also important components of managing kidney disease. There is specially formulated prescription dog food for dogs dealing with kidney failure that will usually have a higher level of polyunsaturated fatty acids (omega-6 and omega-3 fatty acids, which have both shown to be beneficial to the kidneys). The downside is that these types of dog food are not as flavorful, and some dogs may not eat them.
If your dog is resistant to her new diet, talk to your veterinarian. Adding medication can help manage your dog’s symptoms better and make your dog more willing to eat. Your veterinarian may recommend small amounts of tuna juice, chicken stock or other flavor enhancers. It is important not to counteract the diet by choosing the wrong dog food toppings.
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 checkups by your veterinarian to ensure that the medications and diet are optimal for your pet’s disease stage.
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.
Preventing Renal Failure in Dogs
There are currently no known methods for preventing kidney disease. Dietary protein is sometimes restricted, since it can further compound the problem.
Feeding diets with an appropriate amount of protein may help reduce unnecessary wear on the kidneys. Some commercial diets have much more protein than your dog needs, and this excess can damage the kidneys. Talk to your vet about your pet’s dietary needs.
Have your dog vaccinated against leptospirosis, a bacteria that may cause kidney damage even without noticeable symptoms (the severe form of the disease can cause acute kidney failure).
Annual blood monitoring can reveal early stages of kidney damage, which can allow you and your veterinarian to start a kidney protection plan.
And of course, be sure your dog always has access to plenty of fresh, clean water.