Elevated BUN in 5 month old puppy

[renee_rn]

I am the proud mommy of two yorkies. My oldest yorkie, Ellie, is about to be 2 years old and the sweetest, most loyal dog ever. We decided Ellie needed a playmate / sister back in April and got a Yorkie-Poo which we named Zoey. She is also a sweetheart but definitely the most rambunctious of the two. She was the runt of her litter so I always blame her boisterous personality on her size. When I got her she was 1.5 lbs. She is now up to 3.5 lbs. Her favorite thing to do is eat!

We took Zoey last week to get spayed. I had pre-operative lab work done on her. It was optional to have it done and since I had done it when Ellie was spayed, I done it for Zoey. When I picked her up that afternoon the nurse at the vet's office informed me that her BUN was 42 and should be <20. Ok, so I am a critical care nurse so all sorts of critical thinking started running through my mind. The nurse tried to reassure me that "this is most likely because of her being NPO for surgery." They gave her some SQ fluids to "try to flush the kidney's" and said they would recheck it later on down the road. So I rush home and get on my computer and do some research for elevated BUN in dogs and exactly what SQ fluids were because in human nursing world we don't flush the kidney's SQ. When we got home she was urinating a lot and it looked like water. This lasted about 12 hours. So the next few days, I started paying attention at just how much Zoey was drinking and urinating. The first few days she did not drink much so therefore she did put out much. After she got over the first 48 hours of having surgery she started drinking more and I felt like she was probably putting out enough.

So we went back to the vet on Thursday to get her stitches removed and they rechecked her BUN. This time it was 35. My vet told me that at her age she should not have an elevated BUN. Her creatinine has been normal every time. He said while it does not alarm him at 35, he would start getting worried and say she was in kidney failure when her BUN is at 100. He talked to my husband and I about a low protein diet but said at this point, let her eat what she's been eating which is Royal Canine for Yorkies. He said we would keep an eye on this and recheck it at her 1 year check up which will be in February. I am a little concerned that he doesn't want to check it sooner. I feel like I need to keep a closer eye on this than a recheck in February. He also told me that she had the smallest uterus he has ever seen and even though she was as little as she is that he had a hard time finding it and had to move her bladder out of the way to finally find it.

I also explained to him that Zoey loves chicken type jerky treats and I had taken those away from her for the week after surgery just to see if her BUN would improve but had given her 2 the day before her recheck. He felt this has nothing to do with her BUN. She loves the chicken jerky so much that she will steal Ellie's from her and eat all of it. I am somewhat convinced that maybe this did have something to do with it. Also the next day after she had 2 of those treats she barely drank or urinated all day.

So, I am looking for some opinions and some suggestions to those of you who might have had the same issues with your puppies. I am not giving her anymore treats at this point. I am watching her input and output like a nurse mommy would. But I am also concerned since she is so little and the vet talked about how small her uterus was that maybe her kidney's are small too. When we got Zoey she was about 1/2 the size as her sisters. I am very concerned about her kidney function and the outcome of this if I wait until she is a year old to have it rechecked. I just want my baby to be ok and to be able to live the best little life possible without any health problems.

Please let me know what any of you think. I am welcome to all suggestions, opinions, and concerns. These two yorkies are like my children. I cherish them and will love them always!

[Wylie's Mom]

Hi and welcome to YT !

I know you're scared and worried, but everything may be just fine...the problem is that it may take some time to come to that point, unfortunately. We've seen SO many young puppies here at YT who will have this or that odd elevated blood level with no real explanation...only to have it self resolve with time.

If it makes you feel better, maybe split the difference and have the BUN rechecked in 3 mths...?

As you know, these weird anomalies happen in humans too...elevated liver enzymes, weird kidney levels etc...and sometimes there too, there isn't a solid explanation.

Hang in there, I know the waiting and wondering is really tough! Your wee one sounds like a tough little nugget though !

[Maximo]

I agree with Wylie's Mom. Could just be an inexplicable anomaly. Watch your baby for any changes and re-check in 3 months.

Happy to hear her spay went well and that she is recovering nicely.