What does the term "chronic renal failure" mean?

It is conceivable to presume that the term "chronic renal failure" means an arrest of the kidney function resulting in the kidneys no longer producing any urine. In fact this is not true at all since renal failure is the kidneys' inability to excrete the bloodstream's waste products. This definition may sometimes cause confusion because some people may equate renal failure with the kidney's inability to produce urine. Renal failure does NOT mean the kidneys' inability to produce urine. Oddly enough most dogs suffering from renal failure produce even more urine, but with insufficient elimination of waste products.

When is renal failure likely to appear in my dog?

The typical form of kidney failure is the result of aging. In other words, it is a process of "wearing out", known as the aging process. The age of onset of this condition depends on the size of the dog. In most dogs, the first signs of this disorder are exhibited between their ages of 10 and 14 years. However, pedigree dogs have a shorter life span than other dogs. That makes them more likely to develop this disease as early as age 7.

What changes are likely to occur in my dog?

Kidneys are nothing other than filters. When the aging process causes a weakening of the kidneys' filtering function, the blood flow increases in order to improve that filtering function. So as not to become dehydrated because of a loss of fluid in the urine, the dog becomes thirstier than usual and therefore tries to drink more. Because of this, the first clinical signs of a renal failure condition are an increase in the dog's usual water intake associated with an increase of urine production. The clinical signs of a renal failure at a more advanced stage are the following: loss of appetite, depression, vomiting, diarrhea and bad breath. Sometimes ulcer formation in the mouth can also be observed. Whenever a chronic renal failure is associated with such clinical signs, it is called uremia.

How is chronic renal insufficiency diagnosed?

A diagnosis of chronic renal failure can be arrived at after measuring the level of two organic wastes, namely blood urea nitrogen (BUN) and endogenous creatinine On the other hand, a urinalysis is required to complete the renal function test. Elevated levels of BUN and creatinine indicate the presence of chronic renal failure, but they have no predictive value. A dog with a failing renal function may very well show a normal blood count. However, if that dog were to subsequently undergo stress as a result of either sickness or surgery, his/her renal function. may be failing and his/her blood counts would quickly start getting elevated.

Since the problem is basically the aging process of the kidney, is there any form of treatment other than a kidney transplant?

In some cases, the kidneys are completely worn out and cannot be restarted. However an aggressive treatment can prolong the life of many dogs for months, and even years. Such treatment is carried out in two phases, the first of which is to get the kidneys "restarted". To that end, large quantities of intravenous fluids are injected for the purpose of "flushing out" the kidneys. Such a flushing out procedure, known as diuresis, helps to stimulate the kidney function back to normal. If enough functional renal cells remain, this might be enough to enable them to perform their task of filtering organic wastes. This therapy known as fluidotherapy includes the replacement of several electrolytes, potassium in particular. Another aspect of that initial treatment is redefining the nutrition to be given to the dog and administering the appropriate medications for the control of vomiting and diarrhea.

What can be expected from this phase of the treatment?

This first phase of the treatment may lead to three possible outcomes:

1. The kidneys may restart functioning during a few weeks, or a few years.
2. The kidneys start functioning again during the treatment, but fail when the treatment is stopped.
3. The renal function is not restored. There is unfortunately no reliable test for predicting the outcome of this phase of the treatment.

If that first phase of the treatment is successful, what will happen subsequently?

The aim of phase two of the treatment is to keep the kidneys functional as long as possible. This is achieved by one or several of the following means, according to each particular case:

1. A low protein diet. The adoption of such a diet can help maintain the blood counts as close to normal as possible. This usually helps the dog feel better. Furthermore, when the kidney disease has reached a more advanced stage, the lowering of proteins in the diet helps reduce the workload on the kidneys. We can recommend a commercial dog food that contains both the quality and the quantity of proteins required by your dog.
   
   
2. A phosphate binder. Phosphorus is excreted from the body through a filtration process at the kidneys level. Whenever that filtration process becomes impaired, phosphorus accumulates in the bloodstream. This contributes to inducing lethargy and to making the dog lose his/her appetite. Some medications will bind to excess with phosphates in the intestine and so prevent their absorption. This then leads to a lowering of the phosphorus level in the blood.
   
   
3. The administration of fluids at home. Once the condition of your dog is stabilized, that dog may be administered fluids subcutaneously (under the skin). This helps to "restart" the renal function on an ongoing basis, whenever it shows a tendency to fail again. That procedure of fluid administration may be applied either on a daily or on a weekly basis, depending on the degree of severity of the renal failure. Even if such a technique seems to be beyond your abilities, its ease of application will surprise you since dogs are very tolerant of such intravenous therapy.
   
   
4. A medication to regulate the parathyroid gland and the calcium levels. The levels of calcium and phosphorus should be maintained in the blood at a 2:1 ratio. As mentioned above, any increase in the phosphorus level stimulates the parathyroid gland to increase the calcium level by drawing calcium from the bones. In terms of the calcium/phosphorus ratio, such a drawing of calcium may be beneficial, but it may also make the bones become brittle. It is possible to use Calcitriol™ to suppress the function of the parathyroid gland and to increase the absorption of calcium in the intestines. That treatment is recommended if there is evidence of dysfunction of the parathyroid gland.
   
   
5. A medication to stimulate the bone marrow to produce new red blood cells. Kidneys produce erythropoietin which does just that, i.e. stimulate the bone marrow to produce red blood cells.Therefore many dogs with chronic renal failure may have a low red blood cell count, known as anemia. Epogen™ or Procrit™, which are synthetic forms of erythropoietin, are able to correct such anemia in most dogs. Unfortunately in the case of some dogs this medication cannot be used very long, because the immune system recognizes the medication as a "foreign body" and so produces antibodies (of immune proteins) against the medication. That treatment is recommended when the animal exhibits persistent anemia.