A Little More on Renal Failure

I wanted to touch a little more on renal failure since I mentioned  it in yesterday's post.  I won't go into an exhaustive explanation of all the causes or physiological changes that can happen but I wanted to give out some basic info on it.


As I said, this is one of the "Big 3" older cat diseases - the other two being diabetes mellitus and hyperthyroidism. In cats, many times, this is a chronic, progressive condition.  Early on, the owner may not even be aware of it. Although at some point, the vast majority of cats, do show signs - notably an increase in drinking and urination (this could also appear with the other 2 top diseses!), going off food and vomiting. Diagnosis is made though simple blood tests. We primarily look at two values on the blood panel: BUN (blood urea nitrogen) and Creatinine (which is really the more sensitive value of the two). There are other things we use to assess the whole picture of how the cat is doing. These include blood protein levels (albumin and total protein), phosphorous (many times when this rises kitties get nauseous - so it's something we can help bring down with medication), calcium and red blood cell counts. It's important to remember that it takes 66-75% loss of kidney function to see changes in the blood work! That means your cat could have only 50% of his kidney function and his blood work would be normal. This is why I don't hesitate to do blood work again a week or a month later on any sick animal.  Things can change like that, especially in an older pet.


These cats can be managed - not cured. This includes diet changes (if they'll eat it - we'd rather have them eat period than not eat because the only thing we offer is a prescription diet they don't like), subcutaneous fluids (which is easy to do at home for most owners/cat) and various medications to help with symptoms (like vomiting).


In my experience there is tremendous variability in how long these cats live with this. Some go downhill quickly (days to weeks after a diagnosis), others can last months to years. Obviously this also depends on how soon we have caught this and can intervene - another good reason to get yearly (or more frequent) blood work on your senior pet.


There are cases of acute renal failure in cats - notably those who develop a urinary obstruction, which, when removed, typically get back to normal renal function.