Hello everyone,

I live in Russia and I have a 10-year-old cat. He's feeling fine, but some time ago we (together with our vet) started to notice growing BUN in the blood. Every time the blood is taken, BUN is getting higher. Now it's 12,2 with a normal range up to 8,5. My vet says nothing can be done here, but I do not want to sit in my chair and watch my cat's kidney failure progressing. That's why I decided to ask here. I know that medicine is much more developed abroad, so probably there are any means known in other countries to keep the BUN level low.

Thanks in advance.
Regards,
Kloto

This BUN is not that high at all. At this level it could be heart disease, gut disease or kidney disease. Has a urine sample been examined? If the urine specific gravity is low then it could be kidney disease but if it is high then it is more likely to be gut or heart disease, in which case further tests will be needed. Treating the underlying problem should lower the BUN, otherwise for kidney disease a change in diet is the only appropriate treatment.

Hi, thanks for reply. Yes, a urine sample has been examined many times and the gravity is high.
What are other tests or symptoms, which can prove or except a heart or gut disease?

The tests that can be done for gut disease are (you may not need to do them all):

serum B12/folate
serum Trypsin-like immunoreactivity (TLI)
Faecal analysis for parasites
Faecal occult blood (cat must be on white meat diet exclusively for 3-5 days before sample collected),
Faecal alpha-1-antitrypsin
Ultrasound of the gut to detect intestinal wall thickening
Endoscopy

For heart disease the best thing is an ultrasound of the heart (echocardiogram)

Thank you. Which tests would you recommend to do first?
By the way, there was a period when they used to find some small amount of blood cells in the urine. We did an ultrasound examination and it showed that one kidney is not functioning properly. Seems like the tissue is being replaced by tissue of another type (which one is normally represented in kidneys as well, though in another place, hope you understand what I mean), so the ultrasound examination doctor supposed CKD at an initial stage. We did some homoeopathic treatment ("Solidago" by Heel) (actually we are continually doing it now too) and the haematuria disappeared.

I would do the B12/folate and faecal parasites first because they are easy, the most useful and not expensive, then do the faecal occult blood then the ultrasound of the heart and gut. Leave the others till last.

Ok, thank you, I will keep you posted.

Hello Mark,

It seems that no vet organisation in our city can make a B12/folate test. Then we will make a faecal parasites test first, probably it's wise to check for the occult blood at the same time, what do you think? You said a cat should be on white meat diet exclusively before this test is conducted. My cat is on Hill's, is it necessary to feed it with white meat only before examination anyway or can we remain on Hill's?
Thanks.

The cat must be on white meat ie chicken exclusively for 3-5 days before the test faecal sample is collected or the test will be positive anyway. Your vet should be able to send the B12 to a lab in the UK. Try CTDS - if you google them it will come up with their homepage.

We are in Russia, here such things are impossible. In vet stations no one have the necessary materials for B12/folate test, in human labs the amount of blood necessary to be put into the test tube is 10ml, which is extremely big for a 4kg cat. Today we've done the faecal parasites test and it is negative.
What shall we do next?

I thought that we can do this B12/folate test in two approaches. The point is that B12 is done in one tube and folates are done in another one. Each requires 5 ml of blood. I can do one and then, in several days, another one. Is 5 ml a normal amount for a 4 kg cat to be taken at one time and, if yes, what break is required until the next 5 ml can be taken?

If you were going to do that then I would leave a week or 2 between them. The test will require only about 0.5ml of serum (about 1ml of blood) each - check with the lab because although they ask for 5ml for each test they do not need that much to do the test, whatever they claim!

The point is that this is a human lab and I don't tell them that this is the blood of a cat, because otherwise they will refuse. Do you think that 5 ml can harm the cat?

5ml is not a problem at all.

How urgent is it to take these tests? I mean, do several days or a week matter?

no

Hello Mark,

I talked to my vet today about the tests we are going to do (B12/B9). He asked what further interpretation will be. For example, the tests will show the excess or lack of one of these vitamins, then how is it connected to BUN level and what can we do?
Today we took a urine sample for test and the gravity is 1035. This is the first time we have such a low gravity. Previous test showed more than 1050, and the one before it - 1060. So the tendency is that gravity is getting lower and the BUN is getting higher. Remembering the ultrasound examination which showed that one of the kidneys is not functioning completely properly, do you still think that vitamin tests are needed here and that it may not be connected with kidneys?

The reason to measure these is to identify gut disease - if the b12 is low, the folate high or low then this indicates gut disease. This then suggests that the bun elevation could be due to gut disease - it is not really about deficiencies of vitamins, it is just something that happens when there is gut disease (not in all cases) and therefore can be used to make the diagnosis - if the tests indicate gut disease then this can be followed up to see what sort of gut disease and what treatment is needed - correcting the vitamin deficiencies will not make the gut disease go away (not 100% true but don't worry about the exceptions to the rule). The altered vitamin levels do not cause the gut disease they just indicate that it is present.

As for the SG a one off result does not confirm that the SG is incapable of rising - do not make things too complicated. Remember the initial problem - elevated bun - it could be kidney disease but with the high SG at the time that suggested gut or heart disease or dehydration. The point of these other tests is to see whether they explain a cause unrelated to the kidneys and until you get some results you won't know.

Hello Mark,

Here is the result for B12 already: it's 616.00 picogramm/ml.
What would you say?

not abnormal in any way

So then we wait until we do the next test (folates) on the following week.

try and ask the lab if they have enough blood to run the folate on the blood you sent.

It's completely impossible, I already talked to them several times. It's Russia. The only thing they were able to do is to give me another tube, where only 3,5, not 5, ml of blood is required for folates test to be conducted.
I also talked to my vet, he doesn't see any contra-indications for taking as much blood as they need and apart from this we will also do a complete blood count in around 3 weeks. In the same time we will do the ultrasound of kidneys, I will ask them to do gut and heart at once as well. Are there any special preparations for gut ultrasound examination?

No special preparations needed for gut but best only to use ketamine 5-10mg and diazepam 2.5mg (per cat not per kg) in combination IV if sedation is necessary for heart scan.

How can I determine if sedation is necessary or not?

sedation is necessary if the cat won't keep still enough to have the scan

Ah, ok. And if we are able to fix it, then sedation is not necessary, is it? I mean it's not connected to the heart rate and so on, is it?

In the absence of overt heart failure then sedation is usually safe, although there is never any guarantee about these things.

But it is necessary if we are able to fix the cat so that it is still?

As I said above, no.