Functions Performed by the Kidneys
The kidneys perform critically-important functions in both people and animals. The kidneys:
• filter blood and waste products
• help regulate blood pH
• maintain and regulate the body’s water balance
• help regulate blood pressure.
The kidneys also produce a hormone called erythropoietin which is important in red blood cell production. pH is a measure of either acidity or alkalinity of a liquid such as urine, blood and saliva. Optimal pH is best between the very narrow range of 7.3 and 7.5. Read more about pH here.
Who Gets Kidney Disease
Unfortunately, some breeds of cats and dogs are predisposed to kidney problems. Persian cats, for example, are genetically predisposed to kidney problems. However, any animal can develop kidney disease. Kidney damage can be sudden (acute) or it can develop over time (chronic). Sometimes the two conditions can co-exist, such as if an animal with chronic kidney disease suddenly gets a urinary tract infection. Acute kidney injury is usually seen in young and middle-aged animals, since they tend to be more likely to ingest toxic substances. Chronic kidney disease is more common in middle-aged to older animals. Although statistics are lacking for dogs, there are statistics that report chronic kidney disease affects between 10% and 15% of dogs. Chronic kidney disease may affect between 35% and 50% of cats older than 15 years old. It follows that as cats are living longer, this percentage is also growing.
What Happens When Kidneys Are Damaged
While some body parts (liver, bones, arteries, e.g.) can be repaired, the kidneys have a limited ability to repair themselves. Healthy nephrons – the thousands of functional units that make up the kidneys – can increase their output and compensate for damage to a degree. However, if one part of a nephron is damaged, the entire nephron becomes non-functional. If too many nephrons are damaged, kidney function deteriorates, sometimes permanently.
Two Types of Kidney Disease
There are two types of kidney failure – acute and chronic. Both types are dangerous illnesses that can afflict horses, cats, dogs and other animals.
1. Acute Kidney Disease
Acute kidney disease is marked by an all-of-a-sudden failure of the kidneys. Typically this happens when an animal consumes something poisonous or toxic. It can also result from exposure to Leptospirosis, a very serious yet rare bacterial infection. During the process of urine being formed, the bacteria spreads to the kidneys and damages them.
Causes of Acute Kidney Disease
Toxins such as anti-freeze, grapes, raisins, and lilies are well known examples of toxins that are very damaging to the kidneys. Lilies are problems with cats specifically, however, not all species of lilies are toxic. Tiger lilies and star gazer lilies are toxic but peace lilies are not. However, the kidneys can be affected by non-fatal exposure to toxins, medications (even when given at appropriate doses), prolonged dehydration and low blood pressure. The sweetener Xylitol is toxic to cats, for example. Examples of drugs that can be toxic to the kidneys include platinum-based chemotherapy agents and non-steroidal anti-inflammatories (NSAIDs) like aspirin, carprofen and meloxicam. Other causes of acute kidney injury include infections, including bacterial infections, Lyme disease, leptospirosis and feline infectious peritonitis and trauma. Prolonged decreased blood flow, such as when an animal is hit by a car or other prolonged blood loss can also damage the kidneys.
2. Chronic Kidney Disease
Chronic kidney disease happens kidney function deteriorates over a period of time. In cats, this is known as chronic renal failure. With dogs, this is known as chronic kidney failure. Chronic kidney disease can be the result of consuming something toxic over a period of time or repeated exposure to heavy metals or other poisons. A long- standing, undiagnosed infection can lead to chronic inflammation which can also result in chronic kidney disease.
Animas’ diets are as important to their health they are to human health. The wrong diet or one that consists of cheap and substandard protein can tax the kidneys’ capacity for breaking down waste products. This results in excess nitrogenous waste in the system. Symptoms of chronic kidney disease include loss of muscle mass, weight loss and loss of appetite, stemming from excess nitrogen in the body.
Causes of Chronic Kidney Disease
Chronic kidney disease is defined as abnormal kidney function that is present for more than three months. Aging is one of the most common, if not the most common, cause of chronic kidney disease. As noted above, other causes include a history of previous trauma or damage to the kidney, infectious agents like leptospirosis, Lyme disease and drug or toxin exposure. This can include chemotherapy drugs and for this reason, drug use must be monitored carefully. There are some unusual causes of chronic kidney disease including immune-related diseases and, in rare cases, even cancer. Some breeds of dogs and cats have inherited kidney abnormalities that can result in altered kidney function. Abnormal kidney function is sometimes noted in these animals at a very early age, but in others it can take years for signs of disease to become apparent.
Signs of Kidney Disease
• Increased thirst (chronic)
• Increased urination (chronic)
• Decreased urination (acute)
• Decreased appetite as a result of waste products building up in the blood
• Depression, lethargy as a result of waste products building up in the blood
• Vomiting, nausea as a result of waste products building up in the blood
• Halitosis (bad breath) that has a distinct odor known as uremic breath
• Mouth and stomach ulcers. The kidneys produce a hormone that creates the acid to break down food in the stomach. If the kidneys are not working properly and that hormone is not removed, it continues to cycle through the body and this excess acid can create ulcers.
• Pale gums (chronic)
• Discolored urine, straining to urinate.
How Kidney Disease is Diagnosed
Kidney disease is diagnosed through a combination of:
• physical examination findings
• history of the animal
• laboratory analysis.
Physical examination findings are often non-specific, but the history provided by the pet owner can be extremely helpful. Blood tests and urinalysis are the cornerstone of diagnosis. These tests look at nitrogen and creatinine values in the blood and compare them to urinalysis results. Kidney blood values like blood urea nitrogen (BUN) and creatinine can be elevated, but doesn’t necessarily mean there is kidney disease present. A classic example of this is dehydration. In that case, the kidneys are absorbing as much water as they can such that the urinalysis shows very concentrated urine. Conversely, high blood values and normal urinalysis values are a red flag for kidney disease.
Ultrasound examination of the kidneys is a newer diagnostic test that helps determine the underlying cause of kidney dysfunction. This is because the kidneys often develop very distinct changes with the onset of kidney disease. Other tests performed might include blood pressure measurement, a urine culture (if infection is suspected) and urine protein measurement.
As noted above, although the kidneys repair very well, they do have a great reserve capacity. Together, the two kidneys can compensate for a loss of about 67% of TOTAL kidney function before any noticeable signs appear. This is why people and animals can live with just one kidney and why kidney transplantation is so successful in humans. Once the loss of function hits 67%, increased water consumption is observed. After 75% of the total capacity is loss, blood values of certain metrics change.
Some veterinarians may order special tests such as a culture of the urine or a test for Lyme disease or leptospirosis.
Prognosis for Dogs and Cats with Kidney Disease
Unfortunately, the prognosis remains poor for dogs and cats with acute or severe kidney injury, with mortality rates around 50%. However, for those pets that survive, prognosis is reported as very good. There are a few reports that suggest that some pets may have residual kidney damage, but do not show any signs of kidney disease. For chronic kidney disease, prognosis tends to vary but with treatment is often very good for cats. The prognosis closely correlates to the IRIS scale for cats. (See explanation of IRIS scale below.) Unfortunately, for dogs the prognosis is poor overall, even when treated.
How Kidney Disease is Treated
A common treatment designed to flush the excess nitrogen waste in the body is through subcutaneous or intravenous fluids. If after 48 hours of IV fluid treatment, if the BUN metric goes down by only 10 to 15 points, it’s likely that the kidneys are permanently damaged. Continuing this therapy could cause unneeded suffering for the pet. Often veterinarians recommend a special diet. In the past, low protein diets were recommended. The thinking was that a low protein diet reduced the work required by the kidneys to break down protein. Dr. Al Plechner, DVM, recommends small quantities of high quality protein, given more frequently. He believes this is less injurious to the remaining functioning units (nephrons) of the kidneys. A high quality protein for a pet suffering with kidney disease has the same characteristics that a high quality protein for people has. They are:
• Hormone- and antibiotic-free
Dietary therapy is the therapy most likely to increase long-term survival in pets with advanced disease. It does not PREVENT disease, but slows the progression for those animals that have been diagnosed with kidney disease. These special diets have less protein, phosphorous and sodium. They have increased B vitamins, soluble fiber, antioxidants, omega-3 fatty acids and for cats, more potassium. Another concern with kidney disease is phosphorous retention. For this reason, any diet for the animal with kidney disease needs to be low in phosphorus.
Inflammation is not good anywhere in the body, but is particularly bad for pets with kidney disease. There are several anti-inflammatory remedies to help. Omega-3 fatty acids are routinely given. It is not unusual for them to be administered Vitamin E to enhance their anti-inflammatory function. Currently, many vets are also recommending krill oil as a substitute for fatty acids. Another problem encountered with kidney disease is that potassium levels drop dangerously low. This needs to be monitored as well. In some cases, potassium gluconate is recommended.
Treating Acute Kidney Injury
The goal in treating acute kidney injury is to stimulate urine production. This can be accomplished through:
• Fluid support
• GI protectants or antacids
• Treatment of the underlying toxicity, if possible. These must be administered fairly soon after ingestion.
• Dialysis buys time while the team is working to get the kidneys to work again.
Treating Chronic Kidney Disease
A group of veterinarian specialists created the International Renal Interest Society (IRIS) to try and standardize the terminology related to chronic kidney disease. A common language helps to compare results of various studies, when everyone has the same understanding of what terms mean. IRIS created a staging system for chronic kidney disease with the goal of customizing treatments based on the stage the animal is in. The IRIS staging scale is based on:
• Blood creatinine levels – creatinine level is a close marker of kidney function
• Protein levels in the urine – as kidneys start to fail, protein may leak into the urine. This may be an early marker of kidney disease.
• Blood pressure.
(Recently IRIS developed a similar staging scale for acute kidney injury.)
The treatment of chronic kidney disease focuses on slowing down the progression of kidney dysfunction, as well as improving quality of life. Treatment of chronic kidney disease (in both dogs and cats) may include:
• Dietary changes – the most beneficial treatment, particularly because of its ability to slow down the progression of disease. This has been proven with many good studies. This is the therapy most likely to increase long-term survival in patients with advanced disease.
• Fluid therapy -tends to work best in cats. This is more for making the animal feel better, not so much to stop the progression of the disease.
• Omega-3 fatty acid supplementation
• Correction of any underlying diseases
• Treatment of hypertension, if present
• Phosphorus-binding agents – phosphorous tends to increase late in kidney disease and is generally found in proteins. Kidney disease diets are often low in protein for this reason.
• Correction of anemia.
Additional Traditional Therapies for Kidney Disease
• Drug treatment with Calcitriol, a form of vitamin D used to treat low levels of calcium in the blood
• Surgery – if a stone is in the kidney
• Lithotripsy – a form of shock wave therapy (doesn’t seem to work well with cats)
• Dialysis – more prescribed for acute (rather than chronic) kidney disease
• Renal transplantation – very expensive and more often seen with cats but has really fallen out of favor.
Calcium Bentonite Clay as a Natural Complement to Traditional Treatment
Traditional medical treatment can help the animal to cope with some symptoms. Adding calcium bentonite clay is a natural remedy that can bring relief to many of the symptoms that come with kidney failure. There is scientific research that has shown that calcium bentonite clay may be useful in averting osteoporosis. A huge positive with using calcium bentonite clay is that there are essentially NO contraindications to using it. Food-grade calcium bentonite clay is actually safe enough for pregnant and breastfeeding women to use. It is completely safe and non-toxic.
For those veterinarians and pet owners that want natural remedies to both prevent and treat kidney disease, Dr. Plechner recommends using calcium Montmorillonite bentonite clay. He believes adding clay to the animal’s diet enhances traditional kidney disease treatment in dogs and cats in the following ways:
Improves Absorption of Micronutrients
All clays originate from volcanic ash. The calcium Montmorillonite clay that is mined in California near Death Valley has baked in the hot sun literally, for centuries. Experts believe this exposure to these high desert temperatures permits the micronutrient to lose one molecule of water. This in turn creates a negative ion in the clay molecule that allows the micronutrient – once ingested – to enter the cell through the cell membrane. Other essential nutrients are aided in crossing the cell membrane as well, as a result of this negative ionic charge.
Calcium bentonite clay neutralizes harmful toxins that enter the body. This can happen through breathing, eating or through the skin. Bentonite clay is inert when dry. However, once hydrated, the negative ionic charge comes alive. As the clay moves through the digestive tract, it attracts positively charged elements such as harmful bacteria, allergens and parasites Earth’s Natural clay both adsorbs and adsorbs toxins. Positive ions are exchanged with negative ions. Together, the clay and the toxins exit the body through normal elimination channels.
Nitrogen accumulates in the blood stream since the failing kidneys cannot process it all. This elevated nitrogen can result in many problems. The measure of nitrogen is BUN or blood urea nitrogen. Excess BUN irritates mucous membranes in the intestines and stomach. Elevated nitrogen also hinders red blood cell production and the pancreas can become inflamed. Many veterinarians prescribe Carafate to treat such irritation. Calcium bentonite clay contains many trace minerals and it too can provide soothing. However, unlike Carafate, calcium bentonite clay is 100% natural.
As mentioned above, elevated BUN in the system often irritate the gastrointestinal tract. This irritation can result in vomiting and diarrhea, as well as nausea. Calcium bentonite clay is well known as an anti-diarrheal and will also soothe the intestines. Calcium bentonite clay can also help with absorption of food, which is critically important during times of stress and illness.
Kidney disease often creates an imbalance in the ratio between potassium and calcium. Calcium bentonite clay provides both potassium and calcium, which can help correct any imbalance of these two minerals as a result of failing kidneys.
Osteoporosis from Phosphorous Retention
Often, animals suffering from kidney disease retain phosphorus, which is a serious issue. When functioning well, the body works to maintain a ratio of 1:1 or 1:2 of calcium to phosphorus. When an animal is retaining phosphorous as a result of kidney disease, the body frequently removes calcium from bones. This is an attempt by the body to maintain the normal 1:1 or 1:2 ratio. When this happens, the result is osteoporosis.
Researchers at the Fraunhofer Institute for Cell Therapy and Immunology and Fim Biotect in Germany found that clay was equally as effective at binding phosphorous as conventional binders. They also concluded it was safer than conventional phosphorous binders. Specifically, these researchers determined that clay can be used for longer periods of time than conventional binders. They go on to say that it can help stabilize patients with kidney disease and improve kidney function.
According to Dr. Plechner, including calcium bentonite clay (which is high in chelated calcium), can reduce bone loss that occurs due to phosphorus retention. Bentonite clay is often used regularly by both pets and people that suffer from osteoporosis or lack of bone density but do not have kidney disease. NASA commissioned a study of calcium Montmorillonite clay in the 1960s. There was a concern with astronauts developing osteoporosis from lack of gravity for extended periods. Those researchers concluded that consuming calcium bentonite clay did stop pathological changes in the long bones of the animals studied. They found that it also helped to correct loss of bone density.
Arizona State University has studied the ability of calcium bentonite green clay to kill Methicillin-resistant Staphylococcus aureus ( MRSA) E.coli, salmonella and staph. Calcium bentonite clay is anti-bacterial and as such, it can kill bacterial infections in the kidneys. Amazingly, it also neutralizes toxins molecules that build up in the body during kidney disease.
Kidney disease can afflict both dogs and cats at any age. Acute kidney disease is more common in younger animals, while chronic kidney disease is more common in older animals. There are numerous causes to kidney disease in cats and dogs and there are different treatments available. Calcium bentonite clay is a natural remedy that can complement traditional treatment for kidney disease. In addition to help animals suffering with kidney disease, calcium bentonite clay can help with other ailments including arthritis, parasites, itching, yeast infections and diarrhea. Calcium bentonite clay can also be used daily for general health and wellness. Visit our testimonials page to see all of the ways our calcium bentonite clay has helped people and their pets.
Kidney Disease: Diagnosis and Treatment, Dr. Kelley Diehl, DVM, MS, DACVIM
How Does Clay Help Reverse Kidney Disease?