filter waste products from the blood, and discard them in urine. Damaged CKD
kidneys cannot perform this function properly, so waste products build up in
the bloodstream and make the patient feel unwell. Dialysis is a
method of filtering the blood to remove the waste products so the patient
feels better. Normally dialysis has to be performed on an ongoing basis.
There are two main types of dialysis, haemodialysis and
peritoneal dialysis. Because of the cost and stress factor,
however, neither type is commonly performed on
cats, although haemodialysis is sometimes used to keep a
seriously ill cat going prior to a
transplant, and peritoneal dialysis is occasionally used for cats with
acute kidney injury.
A limited number of centres in the USA also offer a
method called continous renal replacement therapy (CRRT).
This is the type
of dialysis which people usually think of when they hear the word
"dialysis". It is available for cats at a limited number of
facilities in the USA, and as in human patients, the process lasts several
hours and has to be performed several times a week. It can only be given in
hospital and is extremely expensive, with the Animal Medical Center in New
York estimating the cost at US$20-25,000 for the first
People and pets: common diseases -
kidney disease is a video from
University of California at Davis which provides an overview of what happens
in CKD and shows a dog receiving dialysis. It also features a human CKD
patient talking about how CKD feels.
This entails using the peritoneal cavity as a means of
dialysis. The peritoneum is semi-permeable, so urea/BUN, creatinine and
phosphorus can pass through it. In peritoneal dialysis, a sterile dialysis
solution is introduced into the peritoneal cavity, and this solution then
collects waste products and excess electrolytes by means of diffusion.
However, it is very hard to maintain sterility and avoid infection using
this method, so it is highly unlikely that you will come across this form of
treatment in practice; it tends to be reserved for cases of acute kidney injury.
This is used for acute situations when a cat is
critically ill. It provides continous treatment and is usually only provided
until the cat is stable once again, at which point the cat would often
switch to haemodialysis.