Feline Renal Function Test Results
 

Hi!
My cat, Merlin, is 15 years old and had slightly elevated Bun (38) and Creatinine (2.5) levels on his last two blood tests. My vet says he has kidney disease, but his specific gravity is 1.050 (high normal) which I've read means that he has a pre-renal issue, NOT kidney disease.

Anyone know anything about pre-renal issues or renal function test results? I'm trying to figure out if his results may indicate something serious enough that I need to switch vets to get him treatment. Anyone have a cat with pre-renal issues or have any idea what pre-renal issues even would be?

If not, does anyone know of a trustworthy online vet, either for pay or not? I'm happy to pay for the second opinion if I know the vet is reputable. I'm kind of at a loss of what to do now that I'm not entirely trusting my vet's judgment. :confused:

Thanks!

I do not have any experience with feline CRF or kidney disease but one of our members here (growler) does and will be able to help. She usually doesn't log on until later in the evening (pacific time). Here is the thread she started that has lots of great information....

[url]http://www.pets.ca/forum/showthread.php?t=45017&highlight=duffy+crf[/url]

Thanks Rainbow!!

Ooooops, I forgot to say welocme to pets.ca :thumbs up I'm sorry to hear about Merlin :grouphug: but it does sound like you have caught it early so hopefully diet modification will help. :fingerscr .....I know it has helped Growler's cat, Duffy. :goodvibes:

Also, sugarcatmom (another member here) is another cat guru and will also be of great help to you. :thumbs up

Just out of curiosity, why do you suspect pre renal? Is it because they are still concentrating?

[QUOTE=LynMarie;584183]Hi!
My cat, Merlin, is 15 years old and had slightly elevated Bun (38) and Creatinine (2.5) levels on his last two blood tests. My vet says he has kidney disease, but his specific gravity is 1.050 (high normal) which I've read means that he has a pre-renal issue, NOT kidney disease.[/QUOTE]

Sounds like you have been doing your homework. :thumbs up

As a general rule for tubular renal disease the concentrating ability of the kidneys will lost even BEFORE the BUN and creatinine will be elevated. There is a subset of cats that can retain the ability to concentrate urine and still have renal disease.

Was a complete urinalysis done? What is the protein level in the urine? Have radiographs or ultrasound been done?

Is there dehydration present which may explain the BUN and creatinine elevations as pre-renal?

Also do you know what the albumin, total protein and phosphorus levels are? Can you get these values?:pawprint:

[QUOTE=LynMarie;584183]Hi!
My cat, Merlin, is 15 years old and had slightly elevated Bun (38) and Creatinine (2.5) levels on his last two blood tests. My vet says he has kidney disease, but his specific gravity is 1.050 (high normal) which I've read means that he has a pre-renal issue, NOT kidney disease.

Anyone know anything about pre-renal issues or renal function test results? I'm trying to figure out if his results may indicate something serious enough that I need to switch vets to get him treatment. Anyone have a cat with pre-renal issues or have any idea what pre-renal issues even would be?[/QUOTE]


The thing here is pre-renal issues basically is early stage kidney failure. Unfortunately with most cases the kidneys cannot regenerate themselves - you cannot regain tissues whose function is lost. The difference in the name has to do with where the problem is, is it in the structure of the kidneys (kidney failure) or in the physical tubing structure just before the kidneys (pre-renal before the kidneys).

My cat Duffy was first diagnosed with pre-renal atozemia, with the next series of blood & urine tests it had progressed to renal atozemia, her most recent test results the Dr wrote renal insufficiency. Pretty much all the same to me - early stage kidney failure.

So yes my cat has had pre-renal issues and now has renal issues - they are the same, you want to treat this the same as you would treat it if they called it Chronic Renal Failure.

Your cat, same as mine, needs:
-a canned food that has good quality protein - no dry food,
-low in phosphorus and potassium,
-preferrably grain-free,
-they need to drink water,
-and they should have a tsp or 2 of water added to the canned food,
-you need to make sure the cat eats & doesn't go more than 24 hrs w/out eating
-full blood & full urine testing done @ least every 6 months
-you to be aware you will need to consider giving subq or have a vet give IV fluids at some point if your cat becomes dehydrated
-you to be aware that your cat may need medication @ some point
-you to have a positive outlook on the situation - animals can sense when you are upset and this may lead to their condition becoming worse ~ self-fulfilling prophecy

Do you really not trust your vet? Is that why you are thinking to switch vets to get treatment? Or are you thinking to try Homeopathy?

I have chosen to go the route of Homeopathy with my cat because her numbers were not high enough to need medication but I did not want to wait until that time before I took action. Duffy is taking some supplements prescribed my my Homeopathic Vet which has helped her overall health and has started to stabilize her numbers.

My thread has been linked for you, please have a read through the various links in it and please feel free to ask questions. :)

I think we may be talking about a couple items here. I would like to explain some terms.

pre-renal is NOT early renal disease.

When talking about pre-renal it is an anatomic reference to azotemia. Just as post-renal causes of azotemia do not refer to complete renal failure. Pre-renal indicates factors that can raise BUN and creatinine before they reach the kidneys. If the BUN and creatinine rise because of the kidney, they are renal causes. If the BUN and creatinine rise due to causes after the kidney (such as an urethral obstruction) then it is called post-renal.

The most common and usual cause of pre-renal azotemia is dehydration.

Also note that you can have pre-renal, renal and post-renal causes of azotemia all together or in combinations. So just because an animal has pre-renal azotemia, it is does not mean that it will become renal or post-renal azotemia.

Hope that helps:pawprint:

Additional thoughts on Merlin.

Pre renal azotemia is often associated with mild azotemia - slight elevation of the BUN and normal or near normal creatinine. Azotemic patients with evidence of adequate urinary concentration (specific gravity >1.040 in cats) have pre-renal azotemia.

A list of pre-renal causes: consumption of a high protein diet, gastrointestinal hemorrhage, treatment with corticosteroids (as it creates a catabolic state), dehydration, hypovolemia and decreased cardiac output.

Side note on chronic renal failure in cats: most will have unconcentrated urine with a specific gravity of 1.008-1.012. Some dogs can have minimal concentration up to 1.025 and some cats can concentrate up to 0.035

Important note: since the specific gravity sometimes alters a diagnosis of pre-renal versus renal, it is important that this is not an old sample that has 'dried' up and become concentrated. I have seen cases misdiagnosed as pre-renal because of urine that was 'concentrated' by evaporation.

How is Merlin doing by the way? :cat: