Chronic Kidney Disease in Dogs

A CKD or Chronic Kidney Disease diagnosis can be accompanied by many unknowns for guardians. While this diagnosis doesn’t go away– CKD affects 10% of dogs, most of who are older; dogs can live years beyond the prognosis with the right information and proper tools.

The Role Kidneys Play

The kidneys are filtration systems. These two bean-shaped vital organs are tasked with conserving crucial minerals, disposing of harmful byproducts, controlling water balance and body fluids, pH levels, and blood pressure, and producing hormones like erythropoietin.

The kidneys’ function is also to ensure calcium to phosphorus balance.

What is Kidney Disease?

Kidney (renal) disease is a broad term for any disease process that leaves the kidney unable to filter toxins out of the body and maintain water balance in the body.

When the kidneys do stop functioning properly, waste byproducts build up in the body, causing more health problems, making your pet feel sick, and in later stages of disease progression, renal failure.

Types of Kidney Disease

Acute Renal Failure

Kidney function suddenly declines within a week or months. Generally, infection or ingesting a toxin like antifreeze, pesticides, or cleaning products causes acute renal failure. Even too much vitamin D can be poisonous to your dog’s organs.

Chronic Renal Failure

The loss of function is a slow progression, happening gradually over years.

What are the Stages of Chronic Kidney Disease in Dogs?

CKD is often referred to as early, moderate, or advanced, though it’s also numbered 1-4, 4 being the most severe. The International Renal Interest Society (IRIS) staging system created these stages to judge the severity of kidney disease. The higher the stage number, the more signs you’ll see in your dog.

Stages are set by the creatinine levels, so when creatinine is at X, your dog is in stage 1; when it’s Y, the dog is in stage 2.

Ultimately, being proactive and getting annual bloodwork can identify subtle changes in the body long before they start showing symptoms of kidney dysfunction.

In the beginning stages of renal disease, the concern is dehydration because kidneys are not conserving fluids and producing dilute urine. The kidneys cope with their inability to filter toxins and byproducts by producing a larger amount of more dilute urine. You may notice your dog drinking and urinating more and asking to be let out several times a day.

Disease progression causes a cascading effect in the body, dominoes falling one after another. Toxins built up in the body will increase, and the symptoms will worsen, damaging kidney function and progressing the severity of the disease.

When the kidneys aren’t working well, all systems in the body are also affected – the heart, liver, and pancreas, even blood pressure. High blood pressure (hypertension) occurs in as many as ⅔ of all CKD cases. However, this may be an instance of the chicken or the egg since hypertension worsens kidney function, and a progressive decline in that function can lead to poor blood pressure control.

What’s important to remember is that a diagnosis shouldn’t send you spiraling. Focusing on the stages, the numbers, or lab results can be overwhelming. Instead, focus on what you can do for your dog and his quality of life.

What are the Signs of Chronic Kidney Disease in Dogs?

Signs vary from subtle and progress slowly to a severe and sudden onset.

The initial signs can include:

Drinking and urinating more and asking to be let out several times a day
- They will be producing a larger amount of more dilute urine.
Weight loss/loss of appetite
Lethargy
Vomiting
Diarrhea
Poor coat quality

Signs of advancing kidney disease include:

Dehydration – severe dehydration
Increased water consumption and urination
Lethargy
Increased loss of appetite, anorexia, or weight loss
Diarrhea
Neurological signs, even seizures, due to high ammonia levels in the blood

Most don’t notice symptoms until 70+ % of function is lost because the kidneys have ample capacity to perform their various functions. That means at least two-thirds of the kidneys must be dysfunctional before you see any signs.

What Causes Chronic Kidney Disease in Dogs?

Often the cause is unknown or difficult to pinpoint because the onset is slower, and many different conditions can cause it. Your dog’s body is interconnected. When one system has problems, it can often lead to issues elsewhere.

The potential causes are:

Urine blockages like kidney stones
High blood pressure
Dental disease
Genetic predispositions
Autoimmune diseases
Diabetes
Severe dehydration
Chronic dehydration
Toxins

How is CKD Diagnosed?

Signs like weight loss, weakness, and poor coat quality can be seen with many other diseases, so blood and urine tests are needed for a diagnosis. The blood tests will look for elevations in creatinine and Blood Urea Nitrogen (BUN) which are indications of kidneys not filtering out these waste chemicals. Mild elevations of creatinine and BUN can be from dehydration but repeated, or high levels are diagnostic for kidney disease.

New blood tests like SDMA– a genetic marker of kidney function- can help identify kidney disease early, sometimes years before signs show. Many veterinarians include it in annual wellness screenings, so you could ask at your next appointment.

There’s no cure for CKD, and the disease is progressive, but the earlier CKD is diagnosed, the more time you have to be proactive about his care and potentially delay the disease’s progression with proper nutrition. Consider annual bloodwork checking BUN, creatinine, phosphorus, and potassium for dogs greater than 8 years old to develop a baseline and for early detection.

Diet’s Role in CKD Care

Fluid therapy and diet are the staples in treating chronic kidney disease. Dogs can live for years when the disease is caught early, and a care plan is put in place. 

A CKD diet aims to nourish the body and protect the kidneys by lessening their workload.

The previously accepted approach to this was Low Protein / Low Phosphorous diets.

The low-protein approach started because of a general thought that the waste product of protein, urea, was taking a toll on the marginal kidney. One of the indicators of kidney health is the levels of urea in the blood, called blood urea nitrogen or BUN. Since urea is excreted by the kidney and marginal kidney function can lead to a buildup of urea in the blood, the thought was that reducing the amount of dietary protein would reduce the levels of urea.

 But no studies have shown that restricting protein will prevent further deterioration of kidney function in dogs and cats—quite the opposite. On restricted protein diets, CKD patients were not able to meet their protein needs. Inadequate amino acids can lead to muscle breakdown. This breakdown of muscle will cause an increase in creatinine, which the kidneys have to clear. Muscle wasting can also be mistaken for worsening CKD in these patients.

The current school of thought is that moderate amounts of high-quality, animal-based proteins are needed to nourish the body while not overtaxing the kidney function.

Dr. Pierson agrees with this sentiment. “With regard to how protein affects the kidneys, it’s important to understand protein is not the enemy of the cat kidney. Protein doesn’t cause kidney disease. It doesn’t exacerbate kidney disease. It is not the enemy of the kidney.”

As well as Dr. Judy Morgan. “Many veterinarians will immediately recommend a protein-restricted diet in pets with any stage of kidney disease. Protein should not be restricted in early stages of kidney disease, as this will result in muscle wasting and weakness.”

As does Dr. Karen Becker, “Many veterinarians still insist that a renal diet should be low in protein, despite studies showing aging pets — including those with kidney disease — need more protein, not less. But it has to be very high-quality protein.”

As carnivores, cats and dogs need lots of high-quality protein to maintain organ and immune function and healthy muscle mass.

All ingredients in your dog’s food should be fresh, highly bioavailable, easily digested, and highly palatable.

The Importance of Real Whole Food Nutrition in a Renal Diet

In the canine kidney patient, the goal is to minimize phosphorus levels while nourishing the body with moderate amounts of high-quality animal protein. We also want to support kidney function with proper ratios of Omega-3 fatty acids and replenish losses from the symptoms of CKD. All can be accomplished with clean whole food nutrition.

Moderate, human-grade, bioavailable protein

The quality and source of protein are very important to a dog suffering from CKD. Moderate amounts of clean, wholesome meats and organs are easily absorbed providing the CKD patient with the necessary amino acids to prevent weight loss or cachexia. This approach will nourish the body and support the best quality of life.

 In the case of kidney patients, something as simple as an egg can provide precisely what the body needs. Ingredients like eggs are multi-functional. The egg itself is a complete protein and low in phosphorus, and the shell is rich in calcium carbonate, which binds phosphorus to the gut so it can be eliminated. Doing so lightens the kidney’s workload and reduces the ill effects of the compromised organ.

The correct blend of skeletal meats (beef), organs (beef liver and beef kidney), and rice can lead to reduced levels of phosphorus. This delicate balance can nourish the canine without taxing the kidney.

Controlled phosphorous

Controlled phosphorus protects kidney function and can be accomplished in two ways. One way to control phosphorus is through reduced phosphorus content in the food. The second way is through binding the phosphorus in the gut. The first approach can be attained through correct proportions of nourishing whole foods, which in proper combinations have reduced levels of phosphorus. The second approach is accomplished by selecting the correct foods to bind phosphorus, such as chitosan and calcium carbonate, via cooked ground eggshells.

Healthy Fats

Omega-3 fatty acids help decrease inflammation throughout the body. All dogs can benefit from them, but especially dogs with chronic diseases caused by inflammation such as CKD.

Ideally, these omega-3 fatty acids will come from marine sources or grass-fed beef. Omega-3 fatty acids are some of nature’s strongest anti-inflammatories and are paramount for dogs. In addition to being anti-inflammatory, Omega-3 fatty acids are crucial for immune, nervous system, and kidney functions.

Ground krill is a rich source of these omega-3 fatty acids. And unlike fish oils, krill is so low in the food chain that they do not accumulate toxins that can be found in larger fish.

A few key nutrients

CKD patients have an increased voiding of dilute urine. With this water loss can accompany a loss of water-soluble B vitamins and potassium, so potassium and B vitamins must be added to replace those losses.

High Moisture

Water helps with digestion, circulation, and other bodily processes like perfusion (movement of fluids through the organ), which helps move the harmful byproducts through the filtration system and out of the body. 

The right nutritional framework not only nourishes the body but can slow the progression of the disease, and that can drastically impact the lives of dogs with CKD for the better.

Note: The information provided is educational and does not represent medical advice regarding pets. Please see your vet for an accurate diagnosis of your pet’s condition.

In the canine kidney patient, the goal is to minimize phosphorus levels while nourishing the body with moderates amounts of high-quality animal protein. We also want to support kidney function with proper ratios of Omega-3 fatty acids and replenish losses from the symptoms of CKD. All can be accomplished with clean whole food nutrition.