Chronic Kidney Disease

Chronic Kidney Disease (CKD) is an irreversible progressive and often times fatal condition affecting both dogs and cats.  While cats are more likely to be affected by CKD, with treatment, they tend to enjoy a much longer and better quality of life than dogs with CKD.  

CKD is a difficult disease to diagnose early.  In traditional laboratory panels, the first sign of CKD is decreased urine concentration, but that doesn't happen until about 66% of the nephrons in the kidneys are permanently destroyed!  The BUN and creatinine on the chemistry panel are usually within normal limits until 75% of kidney function is gone.  

A new test called SDMA can help detect kidney disease at 40% of loss of function, and sometimes helps us decide if clinical signs are due to CKD or some other problem, like infection.  But it still isn't a great early detection test. 

 

Kidneys affect so many other body systems.  Pets with CKD are more prone to the following conditions:

  • dehydration due to the inability of the kidneys to conserve water

  • high blood pressure due to activation of the renin angiotensin aldosterone system

  • high phosphorus levels due to renal secondary hyperparathyroidism

  • Bone loss due to renal secondary hyperparathyroidism

  • low potassium due to the kidneys' inability to conserve this important water-soluble mineral

  • anemia because they kidneys secrete hormones that tell the bone marrow to make and release red blood cells, but at end stages of CKD, this function is lost

  • urinary tract infections due to dilute urine

  • protein in the urine due to inflammation and damage to the renal tubules. 

 

Every single one of those conditions either makes the patient feel bad, or causes the kidney disease to worsen in a vicious cycle, or both.  

The good news is that there are many things we can do to help pets feel a lot better longer, even though there is no cure for this disease.  It does require a lot of lab work monitoring and being responsive to changes.  Most cats live with CKD for years if caught at early stages and treatment initiated right away.  My own cat lived 12 very good years with CKD.  Dogs unfortunately tend to pass very quickly once diagnosed with CKD- usually within a year.  

One thing that you can do to help prevent CKD in your cat is to feed a predominantly canned food diet.  Numerous studies have shown that even cats who drink "a lot" of water do not get as much water as cats who eat mostly canned food.  We believe that chronic long-term subclinical dehydration may be a cause for CKD in cats.  Dry cat food can be fed in food-dispensing toys for enrichment but should not be the main source of nutrition in cats.  

Dogs tend to drink plenty of water and we don't feel that chronic dehydration is a cause for CKD in this species.  Previous infection or trauma to the kidneys such as severe dehydration may be involved but we think the kidneys just wear out in this species with age.  Fortunately it is not nearly as common in dogs as in cats.  

We recommend senior early detection lab work, including the SDMA kidney test and urinalysis, in all dogs over 8 years of age, and all cats over 12 years of age.  If your pet has signs of CKD, we may run some additional tests to determine if there is a UTI or protein in the urine, etc.  We recommend the Chronic Disease Add-On Package for pets diagnosed with CKD to help make managing this condition easier for you and to ensure your pet gets all the help she needs.