Chronic Kidney Disease
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What do the kidneys do in the body?The kidneys are an amazing organ that has a lot of functions in the body to help keep us alive and doing well. Apart from concentrating urine, kidneys also act as a filtering mechanism to both balance electrolytes and to remove waste products from the blood stream. The kidneys also produce several hormones to maintain the body’s balance including one which stimulates the bone marrow to make red cells (this hormone is called erythropoietin).
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What is chronic kidney disease?
Chronic kidney disease (CKD) is a long-term process in which the cells of the kidney are damaged, get replaced by scar tissue, and eventually stop working. This is a complex disease process, most common in older cats. CKD really denotes two different disorders, renal insufficiency and renal failure.
Renal insufficiency is used to describe cats with mild signs of renal disease. The body’s kidneys, although not at 100% function, are still working. The most common clinical signs of renal insufficiency include reduced appetite, weight loss, chronic vomiting, dehydration, increased drinking and increased urination.
Renal failure is a progression of renal insufficiency. On lab work, these cats have very high creatine values and are usually very dehydrated, anorexic, and weak. Urine output is variable in that cats that are in complete renal failure will not produce any urine.
Renal insufficiency is used to describe cats with mild signs of renal disease. The body’s kidneys, although not at 100% function, are still working. The most common clinical signs of renal insufficiency include reduced appetite, weight loss, chronic vomiting, dehydration, increased drinking and increased urination.
Renal failure is a progression of renal insufficiency. On lab work, these cats have very high creatine values and are usually very dehydrated, anorexic, and weak. Urine output is variable in that cats that are in complete renal failure will not produce any urine.
How do we diagnose CKD?
A presumptive diagnosis of CKD can be made based on physical exam findings and history. To confirm a diagnosis of CKD, characteristic changes are noted on blood and urine analysis including:
- Signs of dehydration
- Anemia
- High kidney waste products (creatine and urea)
- Changes in electrolytes and minerals including potassium, phosphorous, and calcium
- Low urine concentration (also known as specific gravity)
How do I know how bad my cat's kidney disease is?
Kidney disease is currently divided into 4 stages based on the severity of changes on lab work. A cat in stage 4 kidney disease has about 10% of kidney function left whereas a stage 2 kidney cat may have about 30%.
Staging of kidney disease is based on the standards set by the International Renal Interest Society. For more information on IRIS and staging, please click here.
Staging of kidney disease is based on the standards set by the International Renal Interest Society. For more information on IRIS and staging, please click here.
What are our treatment options for CKD?
The only way to bring back kidney function in a cat with CKD is to give that cat new kidneys. Although kidney transplantation is done at some teaching hospitals in the US, this is not a practical option for our maturing cat population therefore our goals of therapy in cats with CKD is to help protect the remaining kidney function while keeping your cat as happy and content as possible.
The treatment plan for your cat will largely depend on laboratory findings and what stage of CKD they are in. Current therapy can include diet change (to low protein/low phosphorous “kidney” diets), potassium supplements, anti-oxidants, and medicine to support kidney function.
If your cat is in late-stage renal insufficiency or renal failure, intensive therapy may be required. If your cat presents as being severely dehydrated, anorexic, or have significantly elevated creatine/BUN values, more intensive care including hospitalizing your cat and starting on IV fluids, with or without force feeding may be recommended.
As with many other cat diseases, therapy success depends on early intervention is important. For this reason, the AAFP recommends cats over the age of 7 be seen every 6 months and lab work done every 12 months.
The treatment plan for your cat will largely depend on laboratory findings and what stage of CKD they are in. Current therapy can include diet change (to low protein/low phosphorous “kidney” diets), potassium supplements, anti-oxidants, and medicine to support kidney function.
If your cat is in late-stage renal insufficiency or renal failure, intensive therapy may be required. If your cat presents as being severely dehydrated, anorexic, or have significantly elevated creatine/BUN values, more intensive care including hospitalizing your cat and starting on IV fluids, with or without force feeding may be recommended.
As with many other cat diseases, therapy success depends on early intervention is important. For this reason, the AAFP recommends cats over the age of 7 be seen every 6 months and lab work done every 12 months.
What type of long-term monitoring should be done for a CKD patient?
To help your veterinarian understand how well therapy is helping your cat, it is important for you to monitor their behaviour at home, especially appetite, water intake, urination/defecation, and attitude. Depending on how your cat is doing, in addition to routine physical exams, periodic blood pressure analysis and lab work may be required.
