Pet Vet: Helping kitties with kidney problems

January 18, 2016

Jan from Cheyenne, Wyo., writes in about her 11-year-old female cat, Matilda, with kidney problems. Having read a previous article dealing with renal (kidney) disease in felines, Jan and her kitty need some additional information.

Renal disease can represent any process that affects the kidneys and their function. This function in its simplest sense involves filtering the blood, removing waste products and saving body water, ultimately producing urine as an end product.

The early symptoms your companion might show of kidney problems usually involve water intake. Cats and many creatures with kidney disease will commonly drink more water than normal because the kidneys are not doing their job of saving water by concentrating the urine. They must drink more to keep up with the water wasting. Over time, these companions become less and less able to cope as the kidneys slip further and further into failure and they become very ill. This usually results in vomiting and a loss of appetite and, correspondingly, activity. These patients are critically ill. Ultimately this disease is fatal.

The diagnosis of renal disease is made after blood and urine samples. Two parameters analyzed are blood urea nitrogen (BUN) and creatinine. Elevations in these two parameters generally mean a compromise of the kidneys, although they can indicate other issues such as heart disease or obstruction of the urinary tract. The urine is checked for a multitude of factors, some of which relate to the function of the kidneys. One is the specific gravity of the urine — the concentration of the urine which is the responsibility of the kidneys. If they are not doing their job, the urine becomes more diluted, thus lowering the specific gravity. A salient point to mention here is that with any elevation above the normal range in the BUN and creatinine, we know there is less than 25 percent total kidney function at the point where we see these elevations. This is an important fact because it makes it difficult to diagnose a kidney problem before over 75 percent of the kidney function is gone.

In the case of Jan’s cat, she does not relate severe illness at this stage and is treating her cat using a special diet lower in protein designed to take some of the metabolic pressure off the kidneys. Kidneys are responsible for processing nitrogen waste which comes from protein, so in the face of renal disease, a diet lower in protein will take some of the pressure of the kidneys. Are their other therapeutic options? There are, and the first step involves a trip to your veterinarian for a thorough examination and diagnostic testing. Is it chronic or acute kidney disease? How high are the kidney parameters? Are the kidneys showing any signs of functioning at all?

Treatment for kidney disease is based on these parameters, and can involve hospitalization with the administration of fluids through the blood system via an intravenous catheter using a computer pump to try to "flush" the kidneys. I refer to this as "kicking the kidneys into gear." In cases of acute renal failure, meaning the kidneys have shut done rather quickly, this procedure, when done early in the course and with aggression, usually results in a cure. Chronic cases are not usually cured, however, these patients can be stabilized to the point where the process is not progressing and the cats can adapt quite well.

In cats with chronic renal disease, we can teach caretakers to administer fluids under the skin to their cats to augment their fluid intake. This can do wonders to keep cats with this disease stable and living a totally normal life. Some of these patients will sometimes have to have intravenous therapy in the hospital to once again kick the kidneys back into gear, then go home to resume their fluid therapy.

In younger cats that have renal failure that is not responding to therapy, kidney transplant surgery can be performed, replacing one of the patient’s kidneys with a healthy donor kidney. This procedure has been proven successful in some cases, but again, is only done in younger cats and is a very complex surgery and followup.

Matilda may benefit from the fluid therapy done at home at this point in her disease. That is a discussion Jan needs to have with her veterinarian. The key takeaway here is to realize that cats — and dogs — that have been diagnosed with renal disease may have some good options in therapy that can give them a quality life for sometimes several years.





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