There are many different strategies which may be instituted in an effort to treat chronic kidney disease in dogs. Which strategies are employed will depend on the stage of the renal disease in the individual dog. Often, multiple strategies are utilized at the same time.
If an underlying cause for the kidney disease has been identified, this should be treated appropriately, if possible. For instance, if the dog has been diagnosed with leptospirosis, appropriate antibiotics should be administered.
Dietary Considerations in Canine Kidney Disease
In many cases, a specialized diet will be recommended. Renal diets should be restricted in sodium and phosphorus. Though controversy exists about protein levels in canine renal disease, protein restriction is quite often recommended. Numerous commercial kidney diets are available, although some dog owners may prefer a homemade diet formulated with the assistance of a canine nutritional expert. Feeding a kidney diet is often one of the first measures instituted when kidney disease is diagnosed in dogs and cats and is usually advised anytime the blood creatine value reaches 2.0 mg/dl or higher.
Though most kidney diets are phosphorus restricted, phosphorus levels need to be monitored and additional phosphorus restriction may be necessary in some cases. If phosphorus levels remain elevated despite dietary restriction, phosphate-binding agents, such as aluminum hydroxide, may need to be instituted.
In addition to phosphorus, potassium blood levels should also be monitored. If potassium blood levels are elevated, potassium intake may need to be restricted. If levels are decreased, it may be necessary to supplement potassium in the dog's diet.
Another consideration is the development of metabolic acidosis. Abnormalities in blood bicarbonate concentrations and total carbon dioxide concentrations may indicate the presence of metabolic acidosis and may need be treated with the addition of sodium bicarbonate or potassium citrate.
In the event that the kidney failure has caused severe weight loss, or if the affected dog is not eating voluntarily, a feeding tube may need to be placed temporarily to provide nutritional support.
Fluid Therapy in Dogs with Kidney Disease or Renal Failure
If clinically dehydrated, fluid therapy should be instituted for dogs suffering from kidney disease or kidney failure. In some cases, long term subcutaneous fluid therapy (placing fluids under the skin of the dog) may be necessary to prevent dehydration and ensure adequate blood flow to the kidneys.
Controlling Protein Loss in Canine Kidney Failure
Glomerulonephritis is a frequent cause of kidney disease and kidney failure in dogs and protein loss is one of the primary symptoms seen with glomerulonephritis. Although seemingly counter-intuitive, feeding a higher protein diet does not appear to slow the loss of protein in dogs with glomerulonephritis. Because the dietary phosphorus level is easier to control with a low protein diet, protein restricted diets are most frequently recommended, though there is some controversy over this issue.
Angiotensive-converting enzyme (ACE) inhibitors, such as enalapril and benazepril, are also frequently used to slow the loss of protein through the kidneys.
Monitoring and Controlling Blood Pressure in Dogs with Renal Disease
Dogs suffering from kidney disease are at risk of hypertension (high blood pressure). If hypertension occurs, ACE inhibitors, such as enalapril and benazapril, are often used to help lower the blood pressure. If ACE inhibitors are not effective enough by themselves to lower the blood pressure into an acceptable range, other medications, such as amlodipine, may also be added.
Treating Anemia in Canine Kidney Failure
Erythropoietin may be instituted if anemia is present in the dog suffering from kidney failure. Erythropoietin is normally recommended when the hematocrit (a measurement of the number of red blood cells) is 20% or lower and the dog is showing symptoms attributable to anemia.
Controlling Gastrointestinal Symptoms for Dogs with Kidney Disease
Nausea and vomiting are common symptoms of canine kidney disease and kidney failure. These symptoms may be controlled by:
- administration of anti-emetic medications such as metoclopramide and maropitant,
- reducing gastric acidity with medications such as ranitidine or famotidine, and
- protecting the gastrointestinal lining with gastrointestinal protectants such as sucralfate.
Calcitriol and Canine Kidney Disease
Calcitriol is used in cases of canine kidney disease to decrease the level of serum parathyroid hormone, which may reach toxic levels in patients suffering from kidney disease. Calcitriol should not be used in cases where there are elevated blood calcium or blood phosphorus levels.
In the early stages of canine kidney disease, instituting a renal diet may the only treatment necessary. As the disease progresses, other medications may need to be administered or the diet further modified to meet the changes in electrolytes and other symptoms inherent in kidney failure in dogs.
Sources:
Polzin, DJ. "11 Guidelines for Conservatively Treating Chronic Kidney Disease", Veterinary Medicine, December 1, 2007.
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