AK Dog Doc and others/kidneys

[Caroline]

Hi AK dog doc and others,

Two blood tests later my elder dog Charlie (will be 13 on Oct 27th), shows kidney trouble. I had the blood work done originally as a baseline for possible drugs like Rimadyl/Deramaxx. Did a urine today, he peed right in the cup, my good dog . No infection present, so the vet suggests that his kidneys are slowing down. ( I don't have the numbers at hand on his blood work though). Innovative brand kidney diet is suggested with the possibility of diaphoresis(sp?) (dialysis is how I think of it). The vet says that is sort of a one time thing, to bring up remaining kidney function. I did not ask the hard questions today on the phone, like how long will he go like this etc? He loves to play ball still and tries to get in the field when I work Luke the younger dog with the sheep. Any comments from our resident helpful Doc? How about anyone else with a similar experience?

I sure appreciate it everyone,

thanks,

Caroline

[Caroline]

Well of course diaphoresis is shock I think , so ignore that term and my relative ignorance.

thanks,

Caroline

Can one really do a one time dialysis and have any effect long term at all?

[AK dog doc]

Hi Caroline

This isn't a simple short answer. Kidney disease can be fairly complex. It's late here and I'm whacked; I'll try to get to this tomorrow morning if I can. Not ignoring the question, just prefer to give a coherent response.

[lrayburn]

I had a young cat, Birch, with acute kidney failure so my situation is not exactly parallel to yours. However, my vet said that with chronic kidney failure, many animals can be managed, sometimes for years. Birch had pretty advanced kidney failure - your dog may only be in the very beginning stages in which case, at his age, it may not greatly affect the last couple years of his life. The protocol my vet used involved Procrit, fluids and a prescription diet.

 

The Procrit was used because the kidneys are responsible for producing erythropeitin (pardon spelling) which is necessary for the body to produce red blood cells. Without it, many animals with kidney failure become anemic. It was administered as a shot at the vet's clinic.

 

Because the kidneys can no longer efficiently concentrate urine, the animals will urinate more and potentially become dehydrated. For Birch we administered fluids (lactated Ringers solution, subcutaneously) at home every day or every other day to keep him hydrated. Dehydration is a big issue for cats, this may be less of an issue for dogs who tend to drink more readily.

 

Finally, the prescription diet was designed to reduce the stress on the kidneys. I put Birch on a prescription Science Diet formulated for animals with kidney disease. I don't happen to like Science Diet based on the ingredient quality but I figured that reducing stress on his kidneys was the most important thing I could do.

 

There are several cats and dogs at my vet's that have been managing chronic kidney failure for several (one cat - up to eight!) years. If you just found it on the blood work, chances are good that your dog is just in the beginning stages and with careful monitoring and management, your dog could happily live out the rest of his life pretty normally.

 

We'll be thinking about you and Charlie. Let us know what your vet says. I look forward to reading AK Dog Doc's response and learning more.

[AK dog doc]

Okay, kidneys.

 

Without knowing the numbers it's hard to interpret, but the elevated BUN and creatinine (our two main renal indicators) can come from three sources: pre-renal, which means dehydration, renal, which means kindey problems, and post-renal, which means urinary obstruction. Clearly Charlie is able to produce urine so that can't be it. Presumably the urine specific gravity and physical exam did not suggest dehydration (I imagine your vet would have mentioned that). Normally, if you're dehydrated, the body starts conserving water by strongly concentrating the urine. If you are in kidney failure, you are unable to do that. A normal dehydrated dog SHOULD have a high urine concentration as it attempts to hold onto as much fluid as possible. If it doesn't, that generally means it CAN'T concentrate its urine, which may mean there's renal trouble. (You can have dilute urine in the face of dehydration for other reasons, but if I go into detail I'll crash the system with the length of this. I'll assume we have the elevated BUN and creatinine along with a dilute urine and are in fact looking at renal disease.) So, if it isn't urinary obstruction and it isn't primary dehydration, that leaves kidney problems.

 

If Charlie IS in fact in failure, that means he's lost more than 50% of his glomeruli. The glomeruli are the filtration units of the kidney, and once they're gone they cannot be replaced. In order to see an elevation of the BUN and creatinine, you generally have to axe over 50% of them (usually more than two thirds); up to that point the animal can compensate enough to have a normal BUN and creatinine despite the losses (hence the thing about donating a kidney while you're still alive - you still have 50% of your kidney function, so you can run around just fine.)

 

The rate at which the glomeruli fail is variable, and depends both on the process and the individual dog. The most accurate way to determine the process is to biopsy the kidney, but the kidney does NOT like this. It's invasive and injurious to the kidney and requires anesthesia (the kidney may not like that either) and will take even more golmeruli out of the failing kidney. Its real value is mainly as a predictor; it's not going to allow us to effect a cure. Since we can tailor the dog's treatment without prediciting it, and we want as many glomeruli on our side as possible, this is not a recommended procedure. However, if we don't biopsy we don't know the underlying process, which means that no one can *really* predict how long Charlie has. It's quite true (as lrayburn mentioned) that some animals can go for years with renal failure and so long as they're in compensated failure, they live happily. Other ones have a steeper decline, and time will tell which Charlie is going to do. At his advanced years (and good job for getting him so far into elder statesmanship) it's entirely possible he'll live with renal disease for the rest of his life without any real problems and die of something else entirely, hopefully some long and unspecified time in the future.

 

As far as concequences of renal failure, the main ones you'll have to worry about are that they tend to progressively lose weight and muscle mass (since they begin dumping protein into the urine, and that constitutes a loss to the body); they drink and pee a lot (and you must allow him all the water he wants with no restrictions); and they may become anemic (which, as mentioned, can be addressed with Epogen - erythropoetin - although that can be expensive, depending on the size of the animal.) The combination of muscle mass loss, anemia and electrolyte loss (potassium is an important electrolyte not well-conserved in renal patients) means that he may develop some weakness. As the renal wastes rise (this is called azotemia) some animals will get GI ulcerations, which is a blood loss (they can't afford this) and requires them to digest the high-protein content of the blood (this isn't so good either). They may also have a poor appetite just due to the azotemia, but possibly also from the ulcers. We REALLY want renal patients to eat - since starvation is the highest-protein diet out there, and reanal patients don't handle high-protein diets well - so he can't afford anorexia, either. You do definitely want to put him on a special diet to cope with all this - renal failure diets are designed to maximize the efficiency of the kidneys while minimizing their workload, at the same time as addressing the special issues of renal patients - such as the weight loss, and the tendency to have a low potassium and so on. We use Hill's prescription diets at our clinic (and please, let's not have the huge diet debate here - they DO work, and some of their formulations work better than anything else out there including other brand prescription diets), so I'm not able to advise you about how good the Innovative diets work, but presumably they are aimed at the same issues. The Hill's one for kidneys contains a specific fat array that helps dilate the vessels leading to the kidney so as to give them maximum oxygen and nutrition and improve GFR (glomerular filtration rate, the rate at which the glomerulus is able to filter wastes out of the blood). I don't know if the Innova diet does that or not. Your vet can advise you here.

 

One further (but unusual) consequence of renal disease is called metabolic bone disease; most likely you will not have to think about this, but the thumbnail sketch is that they lose calcium out of their bones and replace it with fibrous connective tissue, which renders the bones pliable and rather thick, though lacking rigidity for all their thickness. But I've yet to see this in practise in a renal patient, of which I've treated quite a few, so I doubt you need to know any more about it.

 

As far as diuresis (giving fluids) the purpose of that is to rehydrate a dehydrated animal, and to get them ahead of the hydration curve for a while. Dilution is the solution to pollution, so diluting the renal wastes in the bloodstream means they have less impact on the body, so less neausea and risk of ulceration and so on. I will point out that without the numbers I can only guess how azotemic Charlie is, so he may not be suffering these side effects. However, even if he's only mildly azotemic and/or not dehydrated, upping the blood volume with fluids drives the azotemia down, since they filter it out faster with the increased blood volume. In addition, you can use fluids to address electrolyte disturbances. So, yes, this has value, even if only done once, and it CAN be repeated as necessary. The intent is to rebalance the animal into compensated kidney failure, rather than uncompensated kidney failure.

 

As long as his quality is good, I'd keep going, even if you have to occassionally pop him with some fluids. If you've caught it early enough, you can put the brakes on it with treatment (though we don't cure chronic kidney failure short of a transplant). How much you can slow it down depends on the underlying process and is pretty individual. You just have to let him tell you how he's doing with it.

 

The general rule of thumb on degree of failure is that we start picking it up on the bloodwork when about two thirds of the glomeruli are gone, and there are generally clinical signs at home when you're down three quarters. Since this was caught on screening for another issue, I'm assuming you're between two thirds and three quarters. The earlier you catch it the better, since that gives you time to spare the remaining kidney tissue as much as possible. You DO have to be judicious with certain medications in the face of renal diseaase, but I'm sure your vet has a handle on this and will advise you appropirately.

 

So. Sorry for the dissertation, and hope it wasn't TMI. No kidney is an island, so we have to think about how they affect all the other systems of the body, which makes it a bit complex. Hope that was a clear enough explanation, despite the convoluted nature of the disease.

[Joan]

Wow. What an excellent piece of work from AKDogDoc. Canine kidney failure and human kidney failure are very similar, I see. (I have personal experience with the human sort.) Thank you so much for this post, AKDogDoc. It's a keeper, and I learned a lot. I so much appreciate your knowledge and wisdom and how you share it with us.

[Caroline]

Thank you AK Dog Doc. I will get the creatine and BUN numbers from my vet. I am a biochemist/molecular biologist by training so it was good to read your post and details. I do love my Charlie so, that I am crying right now thinking about it. However he has made it to a great age and today at herding, where the young dog Luke trains with me, Charlie was quite insistent with me that he had to tell the sheep what to do, and then get his stick and bring it to everyone. I just love him so much and he knows what I am thinking. He is a treasure. I will talk to the vet tomorrow about this. I may post a few more bits of information, but I want you to know how grateful and thankful I am for your informative post.

Caroline

[Caroline]

Ok I just talked to the vet and the numbers look like this. BTW I am not trying to second guess my vet, I like her and trust her. Just getting a second opinion for peace of mind.

He has had two blood draws and one urinalysis.

First blood draw was Sept 1: BUN was 41, creatinine was 1.7.

Second blood draw on Sept 17: BUN was 34, creatinine was 1.8.

Normal ranges are BUN 6-29

Creatinine 0.6-1.6

 

Urinalysis showed no sign of infection, specific gravity on refractometer was 1.025, on dipstick it was 1.017. Normal is 1.035.

 

Dog does not look anemic at this time, although CBC not run.

 

My plan is to try modified diet for one month and recheck blood work. Does this sound like a good plan to you? Once again, thank you for your advice and help. I wish I could send you something for your effort that you put into this board. I think we should donate to a local BC rescue in your name.

[nancy]

I'm an English Literature person - so I'm not speaking from knowledge.

 

But, when my mother (at 88) had a heart attack, one of the worries was that she was experiencing renal failure. The doctor recommended dialysis, in the hopes that one try would sort of jump-start her system. Evidently that does often work with people. So it might also with a dog.

[Susan M. & Skipper, Annie and Ben]

Dear AK dog doc,

 

Thank you enormously for your post. I will be printing and keeping that one as a resource for future use/reference.

 

Thank you on behalf of my own dogs, who may face renal disease as they age, and on behalf of all the dogs whose people read these boards. We are now more educated than we were.

 

Thank you especially from those of us who know and love Charlie and his family. Charlie truly is a special dog. He is intelligent, intuitive, loyal, and so many more things. He is the reason I now have border collies. He is lucky that his renal disease was diagnosed before he was symptomatic. He is a loved and respected elder who will be getting the best care possible. (I know his family, remember!) That care will be better now thanks to your input. You are a treasure to more people than you know!

[AK dog doc]

Glad to be of help, and it's nice to be appreciated. I have a dog like that in my life, too, a "why I love and now own BCs" dog, so I understand how special they can be.

 

I'd consider anything above 1.020 normal for dogs (this is per my training by Dr. G, one of the top veterinary renal docs in the nation). I always believe the refractometer before the dipstick. The specific gravity of serum is 1.010; if you are totally unable to concentrate your uurine at all, you'd have a USG of 1.010, which means 1.025 is concentrated. This means that Charlie is able to still concentrate his urine to at least some degree. That's good. The BUN and creatinine are only marginally elevated, so you are early stage yet, and dietary manipulation may be a big help (again, depending on the individual dog). I think trying the diet for a month and then rechecking sounds like an excellent plan.

[Caroline]

Ok next question I have is with the lower protein diet, will he begin to lose muscle mass or is that loss that might happen due to the kidney situation? I have him started on the Innovative Veterinary Diet for Kidney, vet said it is as good as SD, but now that I read the ingredients, the second one is corn. This dog has not has allergy problems before, I think my predjudice against corn is just that, no proof of a problem in my dogs as of yet. A vet tech I know has used Wellness Senior food for her dog with kidney trouble. I am doing as the vet says, just wondered about the corn and the muscle question on lower protein.

Thanks,

Caroline

[Kelliwic Border Collies]

Caroline, my Kaylie was diagnosed with early stage kidney failure several years ago (four, I think). The vets (I took her for a second opinion as well) both attibuted this to her bout with Lyme disease, a few years prior.

 

For Kaylie, the low-protein diet has made a big difference and she's been doing great. We started on the Science Diet Prescription diet, but switched to Eukanuba Early Stage Kidney. A friend had a dog who was on this formula, and the dog passed on; my friend had a brand new bag of the Eukanuba and gave it to me. I saw much more improvement in Kaylie (overall; coat, attitude, and she also liked it better) after the bag of Eukanuba, so we stuck with that.

 

Her BUN and creatinine levels last week were 50.0 and 3.2; very slightly elevated from April. Last week was our first visit to a new vet and nearly every staff member and the vet remarked on how GREAT she looked for 10 years old; they seemed surprised! I just thanked them and didn't bother to correct them (she's actually 11 years old).

 

That's my personal experience with using diet to manage kidney failure...I'm sure each situation is different.

[Kelliwic Border Collies]

Caroline said:

Normal ranges are BUN 6-29

Creatinine 0.6-1.6

 

Interesting that my printout indicates normal range as slightly different:

BUN: 8.0 - 24.0

creat: 0.5-1.4

 

Dogdoc, is this a difference of the equipment used, or the literature used in the school the vet attended, or what accounts for this (very slight) difference? Just curious.

[AK dog doc]

Okay, so quick thumbnail about protein and the glomerulus...

 

A high protein diet will recruit maximum GFR from the glomeruli via vasodilation of the vessels going into the glomerulus. Remember that a high GFR increases the rate at which renal wastes can be filtered out of the bloodstream. At first blush you might think we should feed a HIGHER protein diet to renal patients to take advantage of this effect. However, a renal patient is already maxing out every glomerulus it has in order to compensate for the ones already lost, so all the excess protein does is stress the kidney. This has at least the potential to accelerate the deterioration of the kidney. In addition, humans in renal failure report that they do not feel as well on a high protein diet as a protein restricted diet. We can't ask dogs this question (well, we CAN, but they don't answer us) , but we assume they feel the same. Protiens do produce some nitrogen wastes which are part of the azotemia picture, and azotemia causes depresed appetite, nausea, GI ulceration and malaise. Hence the justification for the protein restriction.

 

An animal with renal failure WILL generally lose muscle mass, REGARDLESS of whether or not it's on a protein restricted diet. A great many of my renal patients some in presenting not for suspected renal disease but for weight loss (generally this is cats, since it may be less obvious in cats than dogs that they are drinking and peeing like racehorses). Gernerally you find a thin, dehydrated animal with very little muscle mass and next to no body fat whatsoever. These are animals who have NOT been on a protein restricted diet, and yet many of them have lost a large percentage of their muscle mass before I ever saw them. The purpose of the protein restriction is to improve quality of life and if possible put the brakes on the deterioration of the kidney which in the long run would potentially minimize the amount of muscle loss. So, yes, they will lose muscle mass, but the intent of a protein restricted renal diet is to minimize that as much as possible. Seems paradoxical, but there it is.

 

As for corn - it's just like most things. Some dogs do well on it, others don't. You have to try it on your dog to know how he'll do. There's nothing magic about lamb and rice or duck and potato or kangaroo and barley. These are just novel protein and carb sources that an allergic dog will not have been exposed to, so they should not provoke an allergic reaction. It is true that there are some items which "commonly" provoke an allergic reaction, but generally there is a VASTLY greater number of animals who do NOT have an allergic reaction to that item than those that do. There are plenty of things *I* can't digest that have nothing to do with the quality or value of the food - just that they're not compatible with my particular system. Most of those things I do NOT have an allergy to; they're more sensitivities or indigestibilities than allergies. The example I usually use to illustrate this is that I have a pal who will puff up and go all blotchy (+/- be unable to breathe) if he eats Dungie crabs. That's an allergy. If I eat green bell peppers I get an upset stomach. That's a sensitivity. Either way, he shouldn't eat Dungies and I shouldn't eat green bell peppers.

 

Megan, the difference in the reference numbers will be the lab normals, based on the type of assay used and the way results are measured. Every different type of machine has its own normal range, so you have to know the lab normals before you can interpret. That's true of nearly everything, with a few exceptions such as urine specific gravity via refractometer, which is just physics, or packed cell volume via microhematocrit (ditto). Physics is (are?) the same everywhere. On earth, anyway.

 

Hope that all mamde sense...

[Caroline]

Thank you Megan for telling me how you are successfully managing your dog with kidney trouble. Especially considering I am the one that started the topic of your breeding program. I appreciate your comments.

Thanks AK Dog Doc, I am going to keep him on this diet for one month. He is not too thin, but he has this thing where he generally doesn't want to eat unless he has already played or been on a walk or done something that day. Two meals a day is ok? That is his norm, I don't want to leave it down for free feed since the other dog will likely gobble it up.

I will post an update when I get the next blood results in a month. I truly appreciate all the help.

Caroline Chamblin

[Kelliwic Border Collies]

Caroline,

I personally feed 2x a day, for adults. I know free-choice works for some, but scheduled feeding means I am sure of exactly how much each dog is eating...and in my case, scheduled feeding also means I am sure the right dog is getting the prescription food.

Good luck!