Many older cats are diagnosed with chronic kidney disease (CKD) or chronic kidney failure (CRF).  When this disease is diagnosed, the initial cause of the kidney damage is usually long gone (this may have happened months or years earlier) and we are left with dysfunctional kidney cells.  Over time, the healthy kidney cells will have to work harder and harder to maintain normal kidney function, and eventually the kidneys wear out.   Once we see clinical evidence of CKD or CRF at least 90% of the kidneys are no longer functioning.  Our goal at this point is to preserve the remaining kidney cells and allow them to work as long as possible.  There is no way to reverse the damage that is already there.

The kidneys are responsible for so many functions beyond urine production, including salt and water balance, stimulating red blood cell production, regulating blood pressure, activation of Vitamin D, and filtering toxins out of the blood.  With CKD, any of these functions can be failing, which leads to a variety of clinical signs:

• Weight loss
• Increased drinking
  
• Increased urination
• Vomiting
• Decreased appetite
• Foul odor to breath
• Lethargy or depression
• Weakness
• Coarse, unthrifty hair coat
  
• Pale gums
• Hard nodules/mineralization of the skin
  

The most common presentation of cats in early CKD is an older cat that has lost weight within the last few months and just seems run down and "old".    Cats in mild to moderate CRF will usually have intermittent vomiting (may be a few times weekly or daily) with weight loss and a decreased appetite.

A blood test to check the kidney values combined with a urinalysis will allow us to see what the kidney function is.  There are two blood proteins that we check that help us to understand how the kidneys are working.  These are BUN (blood urea nitrogen) and CREA (blood creatinine).  Both of these values will be elevated with kidney disease.  Since these markers can also be elevated with dehydration, we always run a urinalysis in addition to the bloodwork.  BUN and CREA are blood toxins when in high levels, and these contribute to the clinical signs we see in sick cats with CRF.

Normal cat urine should be very well concentrated, with a value of 1.035 or higher.  Cats with decreased kidney function will have much lower urine specific gravities (1.010-1.020) and this tells us the kidneys are not working properly.  If the BUN and CREA are elevated, and the urine specific gravity is low, this is usually diagnostic for CKD/CRF. 

The bloodwork will also help us determine how advanced your cat's kidney disease has become.  Other values influenced by the kidneys may be abnormal.  The kidneys are responsible for the excretion of phosphorus from the blood, and in cats with CRF this value will be elevated, adding to the symptoms.  The PCV (packed cell volume, or hematocrit) may be low in CKD because the kidneys are no longer stimulating the bone marrow to produce red blood cells and anemia results.  Low potassium occurs in CRF because the kidneys are not conserving it as they should be.  If we see protein spilling out into the urine, this also tells us that the CRF is more advanced. 

Blood pressure can be quite elevated in cats with CKD/CRF.  A blood pressure check should be done routinely on older healthy cats as well as any cat diagnosed with CKD.

Once we diagnose your cat with CKD, there may be many different treatment options depending on the clinical signs and severity of the kidney disease based on the bloodwork and urinalysis results.

The first thing to realize with treatment for CKD is that we will never be able to cure your cat's disease.  We can try to manage the symptoms and hope to stop the progression as long as possible, but CKD/CRF is ultimately a terminal illness.  That being said, there are many different treatment options available:

• Diet change - this is the first treatment we will recommend for your cat.  Canned food is optimal because it increases water consumption.  A prescription diet will be needed that is low in phosphorus, has supplemental potassium, and has restricted protein.  All of these things will help the kidneys function better.  If only one treatment can be done for cats in CKD, I feel that diet change is by far the most important.
• Increased water consumption - all cats with CKD will benefit from an increase in water intake.  This is because it will help to flush out the circulating toxins in the bloodstream.  Free flowing water fountains and canned food diets are the best ways to increase water intake.
• Fluid therapy - subcutaneous fluids are used in the later stages of the disease process.  Owners can often learn how to administer these fluids at home, which is less stressful for the cats and less expensive in the long run.  Some cats will need fluid therapy multiple times weekly.
• Potassium supplementation - When bloodwork shows that the kidneys are not conserving enough potassium, a gel supplement is given to help regulate this important electrolyte.
• Blood pressure medications - these are given if blood pressure readings are elevated.  High blood pressure can cause heart problems, sudden blindness, strokes, and worsens kidney disease.
  
• Vitamin D supplementation - this will be necessary if bloodwork indicates that the kidneys are not able to stimulate Vitamin D production.  If this occurs and is not treated, crystals can form in the soft tissues and cause serious problems.
• Herbal supplements - there are several prescription products that have shown to help slow the disease process in early CKD, as well as alleviate symptoms in sick cats with CRF.  We carry these products in our clinic.
• Treatment for stomach ulcers/nausea - high circulating kidney toxins can cause severe nausea and create stomach ulceration.  Antacids are given to help ease these symptoms.  There are also anti-nausea medications that work well in cats.

There are advanced treatments available at referral clinics, such as dialysis and kidney transplants.  If you are interested in these treatments, please come and consult with us. 

Because this is a chronic condition, we will recommend routine monitoring of certain blood values and urine tests as well as blood pressure to make sure your cat's kidney disease is being controlled.  Medications may need to be altered or added as your pet's condition advances.

Ultimately, pets with CKD/CRF will become more sick despite treatment.  We believe that quality of life is more important than quantity, and we will recommend humane euthanasia as an alternative to a life of suffering if that point is reached.  We know how hard it is to have a pet with a terminal disease, and we want to help you make the right decision for your pet.  Cats with CKD can live with a good quality of life for months to years, especially if a diagnosis is made early and appropriate treatment is given.