Enteric Dialysis for Pets with Chronic Kidney Disease (CKD)
Enteric dialysis is an emerging therapy prescribed for pets, usually dogs and cats, suffering from chronic kidney disease (CKD). It works by using the digestive system to filter waste-products, helping to reduce the workload performed by the kidneys.
CKD typically shows up in older pets as their organs and systems age. The kidneys become increasingly unable to filter the blood properly, allowing a buildup of unwanted waste products such as toxins, fluids and electrolytes. While currently there is no cure for CKD, there are therapies that can significantly increase an animal’s lifespan and quality of life. Renal dialysis is effective; however, it is prohibitively expensive and time-consuming as a long-term course of treatment.
The usual recommendation for CKD is to focus on disease management therapies, such as enteric dialysis. Other options include therapeutic diets, dietary restrictions, fluid intake monitoring, medications including hormone replacements and nutritional supplements.
The good news for pet owners is enteric dialysis is non-invasive and relatively easy to administer. The treatment consists of adding dietary supplements to your pet’s food. As with all CKD therapies, enteric dialysis works best if diagnosed in the early stages and regularly monitored by a veterinarian.
Enteric Dialysis: How It Works
When food is broken down in the digestive system, small molecules of usable nutrients and waste products pass through the semi-permeable walls of the gut lining and enter the blood stream. These waste products include toxins, chemicals, excess water, unused nutrients and by-products of digestion. As the blood passes through the kidneys, the water-soluble waste products are filtered and excreted in the urine.
Enteric dialysis therapy uses dietary supplements to bind or transform certain molecules so they no longer pass through the gut lining. Waste products remain trapped in the gut until they are excreted from the bowels along with the feces. This reduces the level of waste products in the bloodstream, which in turn reduces the amount of filtering handled by the kidneys.
There are four types of dietary supplements commonly used for enteric dialysis:
- Phosphorus binders, which include chitosan and calcium or aluminum salts, work by electrostatically bonding to phosphorus ions. There is a wide variety of phosphate binders available. Aluminum hydroxide is a common phosphate binder. Epakitin® is a proprietary blend containing chitosan and calcium carbonate.
- Adsorbents, such as special polymers or activated charcoal, trap a variety of organic molecules. Renagel® is the brand name of an organic polymer. Be sure to use food-grade activated charcoal or products approved for feeding to animals, such as Toxiban®.
- Probiotics are live cultures of bacteria that metabolize certain compounds so they cannot be absorbed. These microbes also produce substances that strengthen the integrity of mucosal lining, making the gut less permeable. Use only probiotics approved for your pet species. For example, some probiotic formulas contain lactose, which dogs and cats cannot digest. Azodyl™ and Renadyl™ are two popular brands of probiotic blends.
- Prebiotics, such as glucomannan, inulin and other fermentable fibers, work indirectly by promoting bacterial growth. There are numerous prebiotic blends available for dogs and cats. As with probiotics, use only prebiotic supplements approved for your pet species.
If You Choose Enteric Dialysis Therapy
Schedule frequent, regular checkups with your veterinarian. CKD is a progressive, degenerative condition that is almost always accompanied by other disease conditions. Also, your veterinarian can screen for underlying conditions that may be causing the kidneys to perform poorly.
Bear in mind that enteric dialysis is a complementary therapy that will work best when used in conjunction with a therapeutic diet specifically formulated for pets with CKD. It will not make up for poor quality food or failure to follow dietary guidelines. Pets suffering from CKD run higher risks of nutrient malabsorption and deficiencies, and their dietary requirements will change as the disease progresses from the early to later stages. The best thing you can do is ask your veterinarian about what foods and supplements will help support your pet.
Check with your veterinarian about what enteric dialysis supplements to use and at what dosage. The addition of any dietary supplement can aggravate existing problems or cause new ones. For example, when calcium carbonate is fed as a phosphate binder, calcium ions can permeate the gut lining and end up into the blood stream. This free-floating calcium may bind with phosphorus circulating in the blood and end up crystallizing in other parts of the body, including the kidneys.
Pets with CKD frequently suffer nausea or loss of appetite and may refuse to eat the therapeutic diet. Do not make drastic changes to your pet’s diet. Be cautious when introducing any new foods or supplements. Start with small additions and gradually increase the dosage. If you usually feed one meal per day or leave food in the bowl, try switching to scheduled, smaller meals throughout the day. It is better to have an animal eat a full meal of less-than-ideal food than half of a meal of perfectly balanced therapeutic food.
A lack of appetite may also be due to the fact that kidney friendly diets are notoriously bland. Try adding foods that boost flavor and aroma, such as carrots, fish oil or chicken broth. Be sure these additions are low in minerals, especially sodium, potassium and phosphorus. Avoid bone broths, which may have a higher lead content than stocks made from predominately meat and skin and cooked for much shorter lengths of time.
Please note: this article has been provided for informational purposes only. If your pet is showing signs of illness, please consult a veterinarian as quickly as possible.
“Azodyl™” Vetoquinol USA website. Accessed February 5, 2017.
Bianco D. “Management of Chronic Kidney Disease in Dogs and Cats” Fresno Veterinary Specialty and Emergency Center presentation. March 19, 2013.
“Chronic Kidney Disease and Failure (CKD, CRF, CRD)” Pet Health Topics, Washington State University College of Veterinary Medicine website. Accessed February 5, 2017.
“Epakitin™” Vetoquinol USA website. Accessed February 5, 2017.
Loyd K, Grauer GF. “Kidney Disease in a Cat” Clinicians Brief-Nephrology. December 2011.
Polzin DJ. “Enteric Dialysis™: Does It Work?” Clinicians Brief-Bayer Cutting Edge Symposium:18-20. Clinicians Brief website. Accessed February 5, 2017.
“Renadyl ™” Kibow Biotech website. Accessed February 5, 2017.
Sanderson SL, Bowman D, Nelson T. “ACVN Nutrition Notes: Nutritional Management of Renal Disease” Today’s Veterinary Practice. 2014;4(1):51-56.
“Toxiban® Suspension” Lloyd, Inc. website. Accessed February 5, 2017.
Ulerich L, “Food Fads—Are They Safe?” National Kidney Foundation website. Accessed February 5, 2017.
Zatelli A, Pierantozzi M, D’Ippolito P, Bigliati M, Zini E. “Effect of Dietary Supplements in Reducing Probability of Death for Uremic Crises in Dogs Affected by Chronic Kidney Disease (Masked RCCT)” The Scientific World Journal. 2012:219082.