Elevated BUN

Hi,

My cat (13yr old male) was dxed about 6 weeks ago. At dx his bg was over 700 and BUN 42. He was on 3 units of lantus twice daily and is now down to 1 unit Lantus twice daily. A week after dx his BUN shot up over 100 so we began sub q fluids every other day. BUN steadily went down and got as low as 70. Last week BUN went back up to 90 and today is at 109. BG has been stable at 110-120 for 4 weeks now and he is not spilling any glucose in his urine. What can I do to get this BUN down?? Vet said today that we will keep doing subq fluids (we are doing them at home) and recheck in a week and if the BUN increases again, we may have to make some hard decisions. I am heartbroken.

Thank you!

 

Is his Creatinine normal? BUN is one of the values obtained to help detect Chronic Kidney Disease, but a high BUN can indicate other things as well. There is a great explanation here: http://www.felinecrf.org/diagnosis_blood_chemistry.htm#bun. What does your vet suspect is the cause of the high BUN? Was he tested for ketones, and were there any present? Or are you testing for ketones at home?

Also, what are you feeding him? Cats on a high protein diet will have a higher than normal BUN, but that's not an indication that anything is wrong with the cat.

Most importantly, how is he doing? Is he at home or being kept at the vet? Is he eating, walking, etc.? You mentioned in an earlier post that your vet said he had kidney damage? Can you elaborate on this? Was he diagnosed with CKD and if so, what were his other values like (Creatinine, Phosphorus, Urine Specific Gravity, etc.)

 

The first test they ran when he was dxed showed creatinine was high normal. He was not spilling ketones or glucose. His BG was 90 today after feeding and 1 unit Lantus. They did not run creatinine today but I called them after you replied and requested they run it on Tuesday (when we go back).

I am feeding him a mixture of FFC and Purina DM (dry) with water added to it. Trying to take the dry out completely.

He is at home with us full time. Even dropping him off at the vet for sub q fluids was stressing him out too much so we do them from home now. Most days are good. He acts more fatigued and 'needy' the last week. He is drinking more and eating about the same. He plays a lot at night while he watches TV with me The first vet we took him to that dxed him is no longer his vet. He is the one that brought up CKD but we got rid of him because he was doing all the things that the other 'diabetic kitty moms' were advising against and my gut said he was not doing what needed to be done from the research I had done. The new vet changed a lot and that is when the BUN and BG started decreasing. I will take a look at his other labs when I get home!

 

CKD is manageable with diabetes, and many times vets make things sound a lot worse with CKD than they actually are. What is far more important than the BUN and Creatinine values in determining how bad things are are the signs of CKD that your cat is physically exhibiting. the BUN and creatinine numbers are just indications something might be wrong, not exact measurements of how sick a cat is. It's a very good sign that he's eating and playing and showing improvement!

There are several commercial foods that are good for both diabetes and CKD. To manage diabetes, you want to feed a low carb canned food, and to manage the kidney disease, you want to feed a high quality, low phosphorus canned food. Many vets simply recommend low protein prescription diets for cats with CKD, because they are by default low in phosphorus. However, it's the quality of protein and phosphorus levels that matter, not the protein values. The low-protein prescription kidney diets have only been shown to be beneficial in end stage renal failure and should not be fed long term. In fact, they cause muscle wasting (the LAST thing you want to do to a senior kitty!) when fed in early stage CKD and are completely inappropriate for an early stage cat.

Here's an updated food list with the values for several premium foods: https://docs.google.com/leaf?id=0B8...MzhkYTkxOGM4NThk&sort=name&layout=list&num=50. You're looking for something with less than 10% carbs (for the diabetes) and less than 250 mg/kcal of phosphorus (for the kidneys). The foods I would suggest are Merrick's Before Grain Beef, Merrick's Before Grain Turkey, Merricks' Cowboy Cookout, Merrick's Surf & Turf, Wellness Turkey, and EVO 95% Chicken & Turkey.

If those are out of your price range the next best thing to feed are the low carb Friskie's Special Diet Turkey & Giblets and Salmon flavors. However, I would strongly urge a food without byproducts, and keep in mind that they're still cheaper than the prescription foods and usually about the same as many grocery store brands if bought in large cans or in cases. Studies have shown that the quality of the protein source does make a difference in controlling the disease, and that needs to be considered along side phosphorus content.

Here is a fantastic website with a lot of information about CKD: http://www.felinecrf.org/

 

Hi. I get Wellness Turkey at Petco in large cans. They have small cans, too.

I'm not sure what "high normal" creatinine is in terms of actual test numbers, but I'm not sure kidney disease is severe with a creatinine reading being described as "high normal." I suggest that you check out Tanya's CRF site: http://www.felinecrf.org/, and see if you think your vet is right that the BUN is a reason to make "hard decisions." A BUN of 100 is pretty darn high, I'll agree, but I don't understand why the creatinine is described with the word "normal.: If you look around on Tanya's site, you may be able to find other reasons for BUN to be high, and do some research from there.

If my vet is right, the creatinine is the most important indicator of kidney disease and BUN alone is not a reason to fear CRF/CKD. My vet claims it is more an indicator of dehydration in most cases. The fact that you are giving subcutaneous fluids and that didn't resolve the issue would make me want to do some more research, for sure.

I second Julia's statement that CRF/CKD is treatable. My cat has both that and diabetes, and he even had pancreatitis at the same time recently. Nonetheless, I've been able to get him to feel much better.

 

I'm chiming in as a third. Tess was dx last year as "at risk" or early CKD. Creatinine (Tess was upper end of the normal range), BUN (above normal), phosphorus (rising) and Urine Specific Gravity (low end of normal) are all indicators of CKD, but any one of them could have other causes as well. Cats on a healthy high protein diet will have higher BUN levels, Tess's jumped up 20 points after switching her to canned food, but have settled there. Remember when the standards were set the cats involved in the study were most likely fed a 'normal' diet, dry food low in protein! The more protein we feed the higher the BUN will be. That has to be taken into account when looking at test results.

More concerning to us was that Creatinine was on the high end of normal, phosphorus was creeping up and USG was low. We adjusted her diet and all those levels improved although the BUN stayed where it was. She is eating a high protein diet still, but we make sure the protein is of high quality as well. We have also chosen foods that are lower in phos and I think that made a big difference. If you look at Tess's SS link there is a tab for low carb/ low phosphorus foods that we use. If you are open to feeding raw food that is often lower phos as well.

There is also a tab for her lab results. It's a great way to keep track and track changes. I think you should be able to copy the data in the first 2 columns (saves a LOT of typing) and paste it into a new tab on your SS. Be sure to check the ranges, as your vet may be using a different lab and normal ranges may vary.

All that said, high BUN can have other causes as well. Your results are really high and seems out of line w/ his other renal values. I would have your vet check other problems as well. Has he checked for a urinary blockage? That can elevate BUN and is not unusual in older male cats.

ED to add: We also feed Wellness Turkey and get it in 12.5oz. cans. Petco or PetSmart don't have them here but a local stores does. It brings the cost / oz down to that of FF (which has pretty high phos levels.) If you can't find it locally Wag.com has a really good price and shipping is fast and free over about $50.