Treatment and Prognosis for Chronic Renal Failure in Dogs
Goals of Treating CRF
Chronic renal failure can be present for a long, long time before a dog shows any symptoms of illness. Unfortunately, by the time an owner suspects that something is wrong, enough kidney tissue usually has been damaged to make the condition irreversible. Nevertheless, there are a number of management techniques and supportive treatments that may help delay progression of renal failure and enhance the dog’s quality of life.
The goals of treating chronic renal failure are to alleviate the symptoms of uremia, delay progression of disease and improve and prolong the dog’s overall comfort and quality of life.
It is critical to flush circulating waste products from a dog in renal failure. Most decompensated dogs will not tolerate oral fluids or medications. Dogs showing severe uremic signs (dehydration, anorexia, vomiting) usually will be hospitalized so that the medical team can start immediate, aggressive intravenous fluid and electrolyte therapy. After dehydration has been corrected and the dog’s electrolytes have been restored to their proper balance, fluids can be given under the skin (subcutaneously) rather than directly into a vein. Most owners can be taught to give subcutaneous fluids to their dogs at home without much difficulty. In late stages of CRF, the dog may need subcutaneous fluids daily to remain comfortable. The veterinarian may prescribe various supplements to replace vitamin B, correct acid-base imbalances and reduce circulating levels of phosphorus, as well.
Dietary changes can be quite helpful if customized to the individual dog. Protein is usually poorly metabolized by dogs with chronic renal failure, and circulating phosphorus and sodium (salt) tend to accumulate. Most renal diets have significantly reduced protein, phosphorus and sodium levels when compared with normal maintenance diets. Supplementation with omega-3 fatty acids may be beneficial, as well. Some dogs resist dietary changes, and it may quickly become more important for a sick dog to receive adequate calories than it is for him to receive a perfectly balanced diet. When a dog refuses to eat and starts losing weight, it is increasingly difficult for his body to combat disease. A highly palatable, high calorie diet may be best for a dog in chronic renal failure, at least in the short term, until the effects of the disease can be controlled. Of course, free access to fresh water is always important, but it is critical for a dog with kidney disease. The dog must be able to drink enough water to compensate for its increased urine output in order to prevent severe and debilitating dehydration.
If vomiting and ulceration are involved, a number of prescription and over-the-counter medications are available to decrease gastric acidity, reduce nausea and vomiting and soothe the stomach lining. A veterinarian can also recommend drugs to help control hypertension and anemia, if those are present. Some medications are known to cause renal (kidney) damage and obviously should not be used in dogs with renal failure.
Kidney transplants are available at only a handful of veterinary referral hospitals, but they are gradually becoming more common. Donor dogs are usually found in animal shelters and, if there is a tissue match, that dog donates one kidney to the recipient dog, and the owners of the recipient adopt the donor and provide a loving home for the rest of its life. Kidney transplants are very expensive and require long-term administration of drugs post-transplant to minimize the chance of organ rejection. Kidney transplants are uncommonly performed in companion dogs.
Kidney dialysis is another potential therapy. It is only available at a few veterinary teaching hospitals and highly specialized private referral centers. Hemodialysis involves routing the dog’s blood through special catheters into a machine that is designed to take on the filtering functions of normal kidneys to remove circulating toxic waste products. The procedure lasts 3 to 4 hours and must be done several times a week. Dialysis is extremely expensive and is rarely used for chronic cases of renal failure in dogs.
If treatment and management attempts do not improve renal function and relieve the dog’s extreme discomfort, euthanasia should be considered.
The prognosis for dogs with CRF is difficult to predict and can range from days to years. When a dog is diagnosed with chronic renal failure, its veterinarian is in the best position to discuss the course of the disease and treatment options with the owner. However, since the CRF is always progressive and incurable, the prognosis inevitably is guarded to poor. The focus of management should be on maintaining the best quality of life for the animal as long as possible.