Kidney Problems

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The following are real life cases of Kidney Problems in Dogs that have been treated by Dr. Mike Richards, DVM.

Chronic Kidney Failure
Kidney Transplant for Dogs
Medications that are Linked to Kidney Failure in Dogs
Serum (or Blood) Urea Nitrogen Levels and Serum Creatinine Levels
Kidney Disease - When to Put on Calcitrol
Kidney Failure and High Calcium Levels
Causes and Treatment of Kidney Failure in Dogs
Kidney Failure and Heart Murmur
Kidney Disease or Kidney Failure?
Kidney Disease Family History
Cystic Kidneys
Causes of Canine Kidney Failure
Leptospirosis (zoonotic)

Chronic Kidney Failure 

Question: 

Thanks for your quick reply and help. Hamish's excessive drinking has stopped after six days of Marbocyl and he appears much more himself although a little lazy. He doesn't appear to have lost anymore weight and is eager for his meals. I took a urine sample in for testing today and the test showed his specific gravity is still 1.005. You say that can happen for a lot of reasons, what are these? If it were a bladder infection as our vet suspected and the anti-biotics worked would the S.G by now be normal?

I read up on Cushings from your site but he doesn't have any of the signs and now the excessive drinking has stopped I don't know what to think his coat is excellent and he has no pot belly. He is now on his normal food, should I get more blood tests done or leave him as he seems OK now? The Vet has suggested another urine test in two weeks.

Also the update

Our Vet has now given him a diagnoses of early chronic kidney failure. All his urine samples are all in the region of 1.005-1.008. The vet even remarked that he thought his dipsticks were faulty but this has been confirmed by lab tests. His creatine is in the normal range 97 (20-130) our references are different I think. One question I have is; as his S.G is so low will that mean his creatine levels will start to rise very shortly indicating a worsening of kidney functions or will he continue just with the low SG and no worsening for months or years? I haven't been able to find an answer to this question despite checking your site and other information on line.

Hope you can give us some indication of his lifespan as he is only 6 years old and we previously lost a Great Dane at the age of 22 months from kidney failure who went from "apparently" healthy to comotose in two weeks.

Answer: 

There are three ranges for urine specific gravity -- hyposthenuric (below 1.008), isothenuric (1.008 to 1.012) and concentrated to some degree at all ranges above 1.012. I am not sure why this range isn't called hyerthenuric but it doesn't seem to be. Hyposthenuric urine actually indicates that the kidneys are working to some degree because they make the urine more dilute to get it into this range. Isothenuric urine is not concentrated or dilute and urine that stays consistently in this range can indicate kidney failure or hormonal diseases. However, your dog has hyposthenuric urine and there are some specific causes for this.

These are the causes of hyposthenuria in a single urine sample: 1) Excessive drinking for behavioral reasons (any cause) 2) central diabetes insipidus (lack of production of anti-diuretic hormone, or ADH, by the brain) 3) nephrogenic diabetes insipidus, or resistance to the effect of ADH at the kidney level: a) hyperadrenocorticism can cause this b) hypercalcemia (too high calcium levels -- hyperparathyroidism, metastatic cancer, poison) c) low serum potassium levels d) kidney failure due to amyloidosis e) pyelonephritis (infection of the kidney itself) f) some forms of drug therapy g) very rarely as a congenital defect

Of the things mentioned above, behavioral excessive drinking is probably the most common cause of dilute urine. However, this should not be a constant finding in a series of urine samples, in most cases. So the first step is usually just to test several samples, trying to get at least one at a time when the urine should be concentrated, like the first urine sample in the morning for a dog that doesn't have access to water during the night. We usually ask for several samples taken over the course of a single day, if possible.

If a series of samples reveals consistently dilute urine then it is necessary to start working through the list of possible problems until the cause can be determined.

Learn more about the Causes of Chronic Kidney Failure in Dogs.

Kidney Transplant for Dogs

Question: 

I have a 2 year old Rottweiler who was recently diagnosed with chronic renal failure. The internal specialist we saw found that there was a loss of the corticomedullary junction and slightly dilated renal pelvis, as well as persistent azotemia and USPG of 1.025. He was given an ultrasound of the abdominal area where after viewing the vet described his kidneys as "severely" damaged with a loss of 75% kidney function. He has moderately elevated BUN and creatin levels. We have had him for 1 1/2 years after rescuing him from a neglectful and abusive owner. He was approximately 25 pounds underweight, with severe malnutrition, mange, and a host of other problems. Per the specialist instructions we have begun changing him over to a new low protein diet (Eukanuba) specially formulated for dogs with kidney disease. The vet said his phosphorus and calcium levels were normal. She stated that although he has lost 75% of kidney function he is still in the beginning stages of this disease and referred to his condition as "moderate" at this time. This little guy is a member of our family and my best friend and I will do anything, regardless of cost, to help him have as long and healthy a life as possible. I want to treat this problem aggresively and proactively. Do you have any opinions on what I can do at this point to combat this disease and hold off his inevitable decline for as long as possible. I would give him one of my kidneys if I could. Any help or suggestions you could give would be greatly appreciated. 

Answer:

It is possible to pursue a kidney transplant for dogs at this time. The University of Minnesota and the University of California at Davis (UCD) are the only places I know of where this surgery is being done in the U.S., but it is an available option. I do think that it might be best to continue with medical treatment for the current problem until the presence of chronic kidney failure is well established, though. The urine specific gravity below 1.030 in the presence of increase blood (serum) urea nitrogen levels and/or increased creatinine levels (azotemia) is a strong indication of kidney failure or kidney insufficiency. The general rule of thumb is that about 75% of kidney function must be gone before azotemia and a decrease in urine concentrating ability occurs. It might be a good idea to check several urine samples, especially ones from early in the morning, to see if the kidneys can concentrate urine at times, though.

There some medications that you might consider using to attempt to slow the progress of the kidney failure or to make your rottie feel better.

Enalapril (Enacard Rx) can help decrease protein loss and possibly slow the progression of kidney failure in dogs. It is important to monitor its effects in the first week of use, though. In a few dogs it can make the kidney failure worse. We have used enalapril now in several patients and our subjective opinion is that it is helpful. This medication makes the most sense when there is demonstratable protein loss in the urine. Even moderate protein elevation in unconcentrated urine samples is indicative of protein loss in the urine.

Calcitriol is recommended by some veterinary kidney specialists and avoided by others. It is an active form of Vitamin D which may help to prevent secondary renal hyperparathyroidism. I am not sure who will turn out to be right in the long term, the people for or against the use of calcitriol. We use this and we think it is helpful but we are not sure. An alternative approach is to use phosphate binders (aluminum hydroxide gel, others) to try to keep phosphorous levels from rising. This is the approach favored by the kidney disease specialists that avoid calcitriol use.

It is very important to maintain hydration in patients who have kidney insufficiency. If you can not encourage adequate drinking, it may be necessary to consider using occasional fluid therapy. This is harder to do in dogs than in cats and is utilized less frequently due to this. It is critically important to use fluid therapy if your dog stops drinking or cuts down on drinking significantly, no matter what the cause.

It is important to try to maintain a patient's appetite, so if there is a time when it decreases, appetite stimulants are appropriate. A lot of patients with kidney failure have gastrointestinal irritation and using cimetidine (Tagamet tm), famotidine (Pepcid AC tm) or ranitidine (Zantac tm) can be helpful, as well.

Monitoring the progress of the kidney disease through repeated urinalysis and periodic blood tests is a good idea. Sometimes clinical signs do not occur until after there are significant changes in laboratory values and early recognition of a change in the status of the kidneys can be very helpful.

Medications that are Linked to Kidney Failure in Dogs

Question: 

You said in an earlier post than antibiotics and non-steroidal anti-inflammatory medications used for arthiritis probably cause kidney failure. Would you have available those medications that could cause kidney failure?

Answer: 

I don't have a complete list of medications that have been linked to kidney failure but I can give you at least a partial list.

Among antibiotics, tetracycline at high dosages, gentamicin, amikacin and most sulfonamides and sulfa-trimethoprim combination antibiotics can cause kidney failure in some patients. Of these,the two aminoglycosides (amikacin and gentamicin) are the most toxic to the kidneys but are only available as injections so are rarely dispensed, although they are used in severe infections in hospitalized animals not too infrequently.

The entire class of non-steroidal anti-inflammatory medications can cause kidney damage due to constriction of blood vessels in the kidney. This would include aspirin, carprofen (Rimadyl Rx), etodolac (Etogesic Rx), phenylbutazone (Butazolidin Rx) and others.

I don't think that any of these medications are highly likely to cause a problem in any individual patient, with the possible exception of the aminoglycosides, which must be used very carefully whenever they are used. However, when kidney failure signs occur and any of these medications are being used it is prudent to evaluate the necessity of the use and to consider adjusting the dosage or changing medications, if possible.

There are other medications that are linked to kidney damage to some degree. These include thiatarsamide (old heartworm treatment medication), chemotherapy agents such as cisplatin, amphotercin-B (antifungal agent), enalapril (Enacard, Rx; used for heart failure and sometimes to treat kidney disease because of beneficial effects it has in most patients), methoxyflurane (anesthetic) and iodinated contrast dyes used to help improve the ability to see problems on X-rays. All of these medications have uses that often make taking a small risk of kidney failure reasonable -- but again, when problems occur they have to be considered as possible causes.

Learn to recognize the signs of Kidney Failure in Dogs.

Serum (or Blood) Urea Nitrogen Levels and Serum Creatinine Levels 

Question: 

Could you explain to me in 'simple language' what is the difference between a high kreatonine and a high ureum level in the bloodwork when there is renal failure?

Answer:

The serum (or blood) urea nitrogen level and the serum creatinine levels are both indicators of kidney function. Both of these values tend to rise when the kidneys are not functioning efficiently.

The urea nitrogen level is less specific to kidney damage than the creatinine level. Rises in BUN can occur after a high protein meal, in response to muscle damage, when corticosteroids are being used and when dehydration or urinary obstruction is present when there is no kidney damage. Usually these rises are not severe, though. When kidney disease is present the BUN tends to rise faster than the creatinine so it is sometimes considered to be a more sensitive indicator of kidney function, as long as the non kidney causes for it rise are not present.

Creatinine is more specific for kidney disease. It can rise when dogs are fed diets high in cooked meat but these rises tend to be small. It can rise when there is dehydration or a urinary obstruction even though the kidneys are not damaged yet. However, for the most part rises in creatinine do indicate damage to the kidneys. Over time, the rise in creatinine levels is a little better indicator for how glomerular damage is progressing than the BUN. A chronic slow rise in the creatinine is an indication of ongoing damage.

For both creatinine and BUN, it is important to look at other indicators of how the body is doing to be sure that there isn't a problem like dehydration or urinary blockage leading to the rises in the BUN and creatinine, instead of kidney damage. If the urine is concentrated, kidney damage is less likely. If the patient is normally hydrated but has protein in large quantities in the urine, then glomerular disease might be present even if the BUN and creatinine are not very high. So the BUN and creatinine are important indicators of kidney function but they have to be considered based on the patient's overall condition and the potential for diseases other than kidney disease to be present.

When monitoring chronic kidney disease, sudden rises in BUN are a good reason to evaluate overall patient care to be sure that hydration is good and that there is not an additional problem present, since the BUN rises more easily due to these types of problems. Rises in the creatinine occur more slowly but are a stronger indication of long term damage to the kidney, so rises in the creatinine indicate a need to try to help the body compensate for the loss of kidney function.

Kidney Disease - When to Put on Calcitriol

Question:

My sheltie has just been diagnosed with kidney disease. His BUN is 32; his creanitine level is 1.8. A protein/creanitine urine test showed a protein >excretion of 2.2. His blood pressure is normal. He is on antibiotics in case of pyelonephritis, but one of his vets says he thinks he has amyloidosis. One vet tells me amyloidosis cannot be slowed down at all, and not to put him on calcitrol yet. The other vet tells me it can be slowed down, and that my dog should go on calcitrol now. What do you think about this? My dog's phosphorus level is 3.1. Both vets recommend that my dog go on the Hill's k/d diet. I do not like the BHA and BHT preservatives in this food and am looking for alternatives. Both vets said I could go with the homecooked diet, but will not recommend a canine vitamin supplement for my dog b/c they don't know what a safe level of phosphorus would be. Could you suggest anything? I also need to include calcium carbonate in his homecooked diet, but have yet to find it except in the form of Tums. I have read that Tums can be detrimental to pets. Is this true? If so, where do I get calcium carbonate? My health food store has it but it also contains boron. Please help! I desperately want to do what's best for my beloved dog, but no one seems to want to tell me what that is. I would greatly appreciate any advice. 

Answer: 

The protein/creatinine ratio can help in determining if there is excessive excretion of protein by the kidneys. The test works like this: the amount of protein in a measured amount of urine is compared to the amount of creatinine in the same urine sample. The amount of protein (mg/dl) is compared to the amount of creatinine (mg/dl) and a ratio formed by dividing the protein value by the creatinine value. If this number is less than 1, it is usually considered to be in the normal range. If the ratio is greater than 1, it supports a diagnosis of protein loss through the kidneys. With the urine protein/urine creatinine ratio of 2.2, there is excessive loss of protein through the kidneys. This test can indicate a problem and can also be used to track the problem over time to get an idea of how much change is occurring.

The BUN and creatinine levels reported in the blood work are not excessively high. This does seem like a good time to start treatment since the earlier you start the more long term success you are likely to have. It is important to know the phosphorous levels when contemplating the use of calcitriol. If the phosphorous level is less than 6 mg/dl it is usually OK to start calcitriol. If it is not, then using phosphate binders to get it down below this level would be necessary. In your dog's case this should not be a problem since the phosphorous level is not elevated at this time. I like calcitriol and I think that it helps our patients with progressive kidney disease. There are veterinary kidney disease specialists who do not think that calcitriol is beneficial, so at this time the use of calcitriol still has to be considered to be controversial in veterinary medicine. Hopefully there will be conclusive studies one way or the other over time. Calcitriol does not affect the progression of amyloidosis at all, to the best of my knowledge. What it is supposed to do is help prevent renal secondary hyperparathyroidism, which is a common problem as any form of chronic kidney disease progresses. This is an important benefit for patients with kidney failure but it doesn't have a direct effect on the kidney disease.

I am hoping that your veterinarian's impression that the kidney disease is due to amyloidosis is wrong. Amyloidosis is the deposition of amyloid in the kidneys. This is a form of protein and when it accumulates it eventually causes kidney failure. It can occur in the kidneys and in other organs, as well. The progression of kidney failure is usually faster in dogs with amyloidosis than with glomerulonephritis and the treatment options are much more limited. As far as I know the only way to tell amyloidosis from glomerulonephritis is by kidney biopsy. From a practical standpoint, though, kidney biopsy is not commonly pursued because time will help differentiate between these conditions and knowing which one is present doesn't alter treatment much. Amyloidosis can occur for unknown reasons or it can occur secondary to cancer, so it is a good idea to look carefully for cancer when this condition is suspected.

Glomerulonephritis is a lot more common than amyloidosis. Glomerulonephritis is inflammation of the glomeruli (the filtering structures of the kidney). It can occur secondary to many other illnesses, including many disease organisms (leptospirosis, Lyme disease, heartworms, brucellosis, hepatitis), cancer, pancreatitis, immune-mediated hemolytic anemia, hyperadrenocorticism and systemic lupus erythematosus and other immune mediated diseases. It can also occur as a primary, or idiopathic, illness. Sometimes finding and controlling the underlying problem can arrest the degenerative process and stop the progression of kidney failure. More often, once this problem starts it is slowly progressive over time.

There are treatments that can help with glomerulonephritis. As mentioned above, an effort should be made to find and treat any contributing condition. To help prevent protein loss and control high blood pressure associated with kidney failure, enalapril or other acetylcholinesterase (ACE) inhibitors may be helpful. The usual dosage of enalapril for this condition is 0.25 go 0.5mg/kg once or twice a day. Aspirin may help to prevent blood clotting that sometimes occurs due to glomerulonephritis. The dosage for aspirin therapy for this purpose is usually lower than for other conditions. A dosage for aspirin of 0.5 to 5mg/kg is enough to inhibit blood clotting. A low sodium, low total protein but very high quality protein diet, such as Purina NF (tm) or Hills k/d is helpful. Encouraging fluid intake is helpful. If the serum albumin level drops low enough to cause fluid accumulation in the abdomen it may be necessary to give diuretics. Calcitriol is more likely to provide a benefit in a patient with glomerulonephritis since this tends to be a more slowly progressing disease.

It is possible to make a home made diet for dogs with kidney failure. A good approach to this would be to contact a veterinary nutritionist for specific advice. However, to the best of my knowledge, there is no problem with using unflavored Tums (tm) in dogs for calcium carbonate requirements. One Tums tablet contains 0.5gm of calcium carbonate. It is also possible to find calcium carbonate as the calcium ingredient in some human calcium supplements. I don't know the names but you could probably pick them out by reading the ingredients. Lately most veterinary nutritionists seem to be recommending Theragram M (tm) as a good multivitamin tablet to use in homemade diets. I have also seem recommendations to use Centrum Silver (tm), so it is likely that other multi-vitamins are OK, too.

Kidney Failure and High Calcium Levels

Question: 

Poor Princess seems to be plagued with bad luck. Whenever a refill is ordered timely, the med always arrives the next day. But when a med has to arrive the next day, it fails to arrive. Today was the 3rd. time that this has happened. No one can explain why. This is so weird.

What causes BUN, phosphorus, creatinne, calcium levels to rise in kidney patients and at what rate? The reason it was so important for the Calcitriol to have arrived today was because we needed to get her started on it before the phosphorus level rose to unacceptable levels. It was at 5.1 on the 2-16 blood test. In treating Princess we have had to experience a lot of delays. Much of it beyond our control and we wonder why that is.

Answer: 

Blood urea nitrogen (BUN) and creatinine are removed from the circulation by the kidneys. When the kidneys are not working well, the levels of these hormones rise. This is a direct effect of the damage to the kidneys. Urea nitrogen and creatinine are not particularly harmful compounds but they are good markers for other toxins the kidneys should be removing from the system that do cause serious problems.

High calcium levels in patients with kidney failure are a more complex problem to explain. This probably results from several contributing factors. As the phosphorous levels rise in patients with kidney failure there is an increased production of parathyroid hormone (PTH), which regulates calcium and phosphorous levels, in an effort to compensate for this. Over time, the rise in PTH becomes significant and a condition referred to as renal secondary hyperparathyroidism develops. Low calcitriol levels contribute to this condition, which is why supplementation of calcitriol can be beneficial for patients with kidney failure. The odd thing, though, is that increased PTH should actually cause the calcium level to be lower in the blood stream. The active form of calcium is the ionized form. In most patients with increased total calcium levels caused by kidney failure, the total calcium is high but the ionized calcium, which is what parathyroid hormone actually controls, is low. The total calcium is thought to increase due to accumulation of inactive forms of calcium in which the calcium molecule is bound to other compounds that keep it from working.

To make this a little more confusing, high calcium levels can be harmful to the kidneys -- but only high ionized calcium levels. When total calcium is high in a patient with kidney failure it may be due to a problem like malignant cancer, which causes rises in both the total and ionized calcium levels. In this case, it is important to lower the calcium levels and to deal with the primary problem which is the cancer. When total calcium is high but ionized calcium is normal or low in a patient with kidney failure, the odds are higher that the kidneys themselves have created the situation and treatment should be directed at dealing with the kidney failure. In this situation, the use of calcitriol even when total calcium is elevated, can be beneficial, as long as total phosphorous is below 6 to 6.5 mg/dL and calcium supplements are not being administered.

Causes and Treatment of Kidney Failure in Dogs

Question: 

I just found out that my 2 1/2 year old female cocker spaniel is probably in kidney failure and would like some advice.

On her blood test the BUN value is 149 mg/dL and the creatinine is 7 mg/dL. She is very lethargic, but does not seem to be in any pain. I have been able to get her to drink small portions of water (at a time, a good amount of water, overall) and eat cooked chicken in small portions after giving her about 4 mL of pepto bismol and amforal. My vet is leaning toward euthanising her, but I'd rather let her go naturally, as long as she doesn't seem to be in much pain.

In a response to a letter from Sharon, Dr. Richards indicates that "some patients respond to aggressive fluid therapy, diet, phosphorous binders, B-vitamin supplementation, gastrointestinal protectants such as cimetidine, omega fatty acid supplementation and good nursing care from their owners." I was wondering if I could get a more detailed description of what these different things are and which things I can carry out on my own (and how to) and which require the care of a vet.

Answer: 

The initial thing to do in a dog this young is to try to figure out why kidney failure would occur.

Kidney failure occurs due to poisonings (antifreeze, ethylene glycol), changes in blood flow to the kidney (renal ischemia), obstructions to urine flow, infections, congenital defects and for no apparent reason. Two and half years of age is young enough to be affected by a congenital defect. I don't think this is a really common problem in cockers but there are some congenital kidney diseases recognized in cockers, including kidney fibrosis and improperly formed kidneys (renal cortical hypoplasia). So making sure there is not something obstructing urine flow from the kidney to the bladder, considering the possibility of an infection such as leptospirosis and trying to eliminate that possibility, ruling out toxins and trying to rule out conditions that might lead to reduced kidney blood flow, such as dehydration, heat stroke, blood loss, heart failure, hypoadrenocorticism (Addison's disease) and medications (non-steroidal anti-inflammatory medications rarely have this effect and it is also an uncommon side effect of ACE (angiotensin-converting enzyme) inhibitors used for heart conditions).

In acute renal failure situations, it is really important to institute aggressive fluid therapy as soon as possible. Your veterinarian would have to do the initial placement of an intravenous catheter and monitor care closely, but you could administer the fluids at home if your vet is comfortable with that arrangement. In chronic renal failure there is less benefit from high dosage fluid therapy but administration of fluids is still helpful. In chronic renal failure, it is important to focus on the things that can be controlled that might enhance the kidney damage, so control of phosphorous in the diet, controlling blood pressure, keeping patients eating, protecting their gastrointestinal tract and similar concerns are more important.

Low phosphorous diets are available from your veterinarian or you can administer phosphate binding agents and feed a moderate protein diet. There are a lot of phosphate binders, including aluminum hydroxide, aluminum carbonate, calcium carbonate, and calcium acetate products. Amphogel (tm) has been a popular one but is hard to find now and PhosLo (tm) is another available product. Your vet can help you find one of these products that is available in your area.

Famotidine (Pepcid AC Rx) is a good protectant for the GI tract for patients with kidney failure. Some vets prefer other products and there are several, such as cimetidine (Tagamet Rx).

3V Capsules (tm) are a good source of the omega fatty acid supplements that can be helpful in some forms of chronic kidney disease.

Kidney failure in dogs is harder to deal with than kidney failure in cats and it can be discouraging to try to treat this condition in dogs but there are some successes and it is reasonable to try, especially if an underlying cause like leptospirosis or Addison's disease can be identified and treated.

Check out some Diet Recommendations for Dogs with Kidney Problems.

Kidney Failure and Heart Murmur 

Question:

I have a beautiful 12 yr/ 18# miniature poodle. She was diagnosed 4 months ago with kidney failure and a heart murmer. We started daily sub q's at home immediately. At first twice a day- then once- then twice and now three times a day. Her bun jumped from 115 to 56 to 101 and now 112. Her creatine started at 1.7, 2.6, 1.8 and now 4.6. Her phosp started at 8.7, 4.6, 5.9 and now 9.7. Her heart murmer has been more pronounced with each appt and now it is continuous. She has developed fluid in her stomach and lungs and we have been doing a balancing act between lasix and sub q's. She currently is taking 90 mg lasix per day in three divided doses. Three sub q's 100/75/100. Enacard 6.25 mg am and 12.5 mg in the pm. She developed an ulcer and is taking cimetidine 100 mg three times a day. She is also taking a potassium supplement, B-12 shots for anemia and lixatonic. She was also placed on Clavamox which we have since discontinued because we found that it was a trigger for her vomiting. She collapsed once after a very bad episode of diarrhea and vomiting but soon recovered her strength. The vomiting is only occasional but now the diarrhea is 2x a day but controlled with pepto bismol. Her appetite is good and she has never refused to eat. She still takes pride in her appearance and performs her daily grooming. Her urine appears to be concentrating to a small degree. Her most urgent problem is fluid in the lungs. Our vet advised tapering down the sub q's which triggered more diarrhea and a general unwell feeling. We have now increased the fluids and she is comfortable except for the breathing dfficulty. She has not had any tests for her heart and wonder if there is still something that can be done for her. Have we overlooked any other possibilities to improve her quality of life and help her with the fluid problem? Her energy level is very good considering her condition and her mental state is excellent. Your help would be greatly appreciated. It means the world to our family to know that we are doing everything we can for our girl. Thank you. Betty-

Answer:

In your note, you did not mention whether your poodle is being fed a restricted protein/restricted phosphorous diet, such as Hill's k/d (tm), Purina's NF (tm) or Waltham's restricted protein diet. This can make pets with kidney disease feel better and may slow the damage to the kidneys that occurs over time. These diets are also low salt, which can be helpful, too.

Phosphorous binding agents may be helpful. Over-the-counter antacid preparations (like Amphogel tm) can help lower the phosphorous levels. Sucralfate, a gastrointestinal protectant that may help with ulcers, also may help to bind phosphorous, so it may be worth considering, too.

Recently, omega-3 fatty acids (from fish oils) have been reported to help protect kidneys from some of the ongoing damage in renal failure. Omega-6 fatty acids are reported to be harmful to the kidneys, so it is important to be sure of the composition of any fatty acid products used.

Some veterinary referral practices do either hemodialysis (as is done in humans) or peritoneal dialysis (more common in pets). This can be very helpful but it takes some luck to be close to a facility that offers this care.

It can be hard to balance the fluid administration necessary for the kidneys with the need to avoid overloading the cardiovascular system. If there is a veterinary cardiologist near you, it may be helpful to get help from the cardiologist in managing this situation.

It is not possible to stop the progression of kidney failure in most cases. However, it is possible to slow the rate of damage down and to provide a reasonable quality of life for some time, in many cases.

Kidney Disease or Kidney Failure?

Question: 

How do you determine if a dog has kidney disease or kidney failure. My dog was diagnosted with kidney disease 8 months ago. Now my vet seems to think that Missy's prognosis is poor and he is suggesting euthanatia. She was not eating a week ago and the Emergency Vet Clinic gave her fluids. The next day, I gave her pedialite and pepsid AC and she came back with playing, eating, and no diarreah. However, it has been almost a week later, and she is showing signs of not eating once again (she ate a few bits of cookies, but refuses all other food). I also noticed she is drinking much more water today and goes out much more frequently to urinate. A couple of times she appeared weak (and could not jump a step easily), but then she would turn around and jump a step later. I am beginning to think she is going back down. Since she is 12 1/2 years old, and cannot get her teeth cleaned any longer (too risky according to the vet since she also has heart failure), I wonder if I should just let her go (euthanize) if she continues not to eat in the next few days. I don't want to drag her through a lot, since renal failure is almost always leads to death sooner or later.

So again, my question: how do you tell kidney disease from kidney failure? Is it in the blood test results; i.e., BUN, Creatin, Phosporous. If so what numbers are these usually when kidney failure are involved?

I would appreciate a quick response, since I feel I will have to make a decision I really dread, sometime in the near future. I am going on a trip (4 nights) in another week and am worried about Missy getting even worse while I am away. My daughter thinks Missy will grieve so much for me she will get even sicker. I am prepaired to euthanize her in a couple of days, though, if she does not eat.

Answer: 

I think that most veterinarians, including me, use the term kidney failure to describe any condition in which the kidneys are not able to adequately do their job. This is probably a poor policy. What is happening in most cases is that the kidneys are working, they just aren't working as well as they need to be. This should probably be referred to as kidney insufficiency. The term kidney failure should probably be used to describe the terminal stages of kidney insufficiency, or the point where the kidneys are actually no longer functioning at all. I think the term is so entrenched in veterinarian's vocabulary in its current use that it is unlikely to change, though.

Kidney disease is also used pretty generically. There are a number of possible kidney problems that can lead to the kidneys having enough accumulated damage that they can not adequately do their job. The most common is probably chronic interstitial nephritis, which is disease most closely associated with kidney damage as pets age. Glomerulonephritis, amyloidosis, polycystic renal disease (more common in cats), pyelonephritis, cancer, viral and bacterial infections, hypertension, hypotension and a number of other conditions can cause kidney damage sufficient to induce kidney insufficiency or failure.

There are a number of lab tests that indicate that the kidneys are not functioning properly. When kidneys are working, they produce urine that is more concentrated than the plasma. Typically, a dog should be able to concentrate urine above the specific gravity of 1.020. If several urine samples taken during the day all fail to have a urine concentration greater than 1.020, that would be a sign that the kidneys are not working properly. Blood urea nitrogen (BUN) concentrations above 75 mg/dl are a strong indication that the kidneys are not able to do their job. Creatinine values above 2.5 mg/dl are also pretty unlikely to occur for any reason other than an inability of the kidneys to filter the creatinine from the bloodstream. Rising phosphorous levels (> 7.0 mg/dl) are associated with kidney damage. Falling total protein levels sometimes occur with kidney failure. Anemia is not uncommon when the kidneys really do start to get close to failing entirely.

The big problem with this situation is that we can often treat kidney problems and gain some time, even when they are very serious. I have copied a letter I wrote tonight to another subscriber below, as it has some treatment options in it, so that you have that information. However, what I think that you are asking is this: How do you tell when the kidneys will no longer respond to treatment?

I do not have a sure answer to that question. It helps a lot if it has been possible to get an exact diagnosis of the cause of the kidney disease. This may not be possible at this point and it may not even matter. For now, I think it is reasonable to assume that it is chronic interstitial nephritis in Missy's case.

We have seen patients with BUN values > 180mg/dl and creatinine values > 13.5mg/dl respond to aggressive fluid therapy, diet, phosphorous binders, B-vitamin supplementation, gastrointestinal protectants such as cimetidine, omega fatty acid supplementation and good nursing care from their owners. Due to this, we tend to try to treat patients even when they have very high blood values for chemistries relating to kidney disease. However, if they do not respond to treatment pretty rapidly, with a decline in BUN that is substantial within 48 to 72 hours, we consider that to be a very bad prognostic sign. So response to treatment is the way that we try to differentiate between patients whose kidneys are not working well but who have enough remaining kidney function to allow management of their condition for some time and patients whose kidneys have so much damage that they are unable to respond to therapy.

There is always some point where therapy will no longer help. The bad thing is that we often can not discover where that point is without trying to treat for two to three days, as a minimum, past the time when pets start to feel very bad. That is the sad part about treating kidney failure. When you reach the point where is it obvious that Missy is not going to respond to treatment one more time or when she gives you strong indications that she no longer wants to fight with this condition, it is good that you have the option of euthanasia. This is a problem that can cause significant suffering and I am grateful that we can put an end to that suffering when it is necessary.

Learn to recognize the signs of Kidney Disease in Dogs.

Kidney Disease Family History

Question:

My dog, a 3 year old Brussels Griffon, has a family history of kidney disease on both sides of his parents. His grandfather on his father's side died of the disease at 4 years of age and his great grandfather on his mother's side had chronic kidney failure most of his life, but did live to be 10 years of age. I recently found out this information and informed my own vet. He ran all the kidney function tests which came out normal, but he recommends that I switch my dog to KD due to his family history. Since the protein level is reduced, I'm wondering if this will harm him. What are your thoughts?

Answer: 

There is still controversy among veterinary renal specialists and veterinary nutritionists over the value of restricting protein levels in patients with chronic renal failure. The most recent edition of Small Animal Clinical Nutrition (Volume 4) suggests that it is helpful, though. However, there is no evidence that I am aware of that there is any benefit in using a reduced protein diet in a patient with no identifiable signs of renal failure. So I guess I would lean towards feeding a "normal" diet until there was evidence that your puppy would have problems similar to those that family members have experienced. Checking urine samples or blood samples on a regular schedule would be a good idea, probably.

There is ample evidence to suggest that the protein levels in the renal care diets such as Hill's k/d (tm), Purina's NF (tm) and similar diets are sufficient for adult dogs. I would not be concerned about using these diets as long as there wasn't something like pregnancy, extreme athletic pursuits or other reasons to suspect that a higher protein level in the diet might be necessary than these diets are designed to provide. The safety margin in protein requirement with these diets is pretty big -- adult dogs can survive on about 6% protein if it is very high quality and these diets usually have about 14 to 15% protein. So if your vet is more comfortable with this approach it isn't likely to cause problems.

I think you can comfortably proceed in either direction -- feeding this diet is unlikely to cause problems but it probably isn't necessary at this particular time.

Cystic Kidneys

Question: 

First of all I'd like to say how wonderful your website is. It's so helpful and well organised and has been a valuable reference source for me and I'm very happy to have finally subscribed! Thank you for providing us with all this information!

My question: I have a 1 and 2 month old mongrel female, she has just been spayed about 2 months ago. She was not operated on by my regular vet and experienced several problems. First of all it took her over 2 hours to recover from the anaesthetic - they usually take less than 30 minutes (all my other dogs recovered quickly with the other vet) .. Her eyelid reflexes were almost non-existent for over an hour or more and I was worried to the point of panic that her recovery took so long...

Then she was fine the next day ( a bit groggy and not her usual self but then she had just had an operation). The second day and for the 14 days following she vomited continuously, was lethargic, refused to eat completely, drank excessive amounts of water and kept belching it all out. Her vomit was yellow and frothy.

The vet who performed the surgery told me it was probably acidity resulting from the anaesthetic and prescribed some medicine for her which didn't work. My other vet saw her and said her liver was affected by the anaesthetic and prescribed "motillium", "legalan" -something which improves liver function, and several other medicines which she would only throw up so I stopped using them.. I was giving her cortigen shots twice a day.

One night, around 3 am, she was very uncomfortable and vomitted non stop and passed some strange diarhea - yellowy orangey coloured. I panicked and called the vet who had done the spaying and he put her on an IV drip and gave her a cortigen shot. She was then put on drips for a week and seemed recovered.

Since then she's been whining sometimes, and we didn't know if she was just playing around or in pain - she didn't seem stressed at all, in fact she would frequently be wagging her tail when she did this. And we thought she was only calling her sister (to whom she is extremely attached). About a month ago she vomited several times within an hour and then seemed perfectly normal and was eating so I didn't think twice about it... About a week ago her whining increased and this time she seemed to be very uncomfortable and started vomiting again, excessively, almost like someone with food poisoning! She also stopped passing urine - she would sqaut then get up immediately but wasn't straining or even trying to go..She also lost her appetite and was drinking alot of water. I took her to the vet immediately and he palpated her and said he suspected cystitis and said she should do an ultrasound ( this is the 1st time I've found out that there is an ultrasound for pets here - diagnostic instruments are so hard to find in Egypt for pets!), I was relieved to find they had finally an ultrasound for pets here. She did the ultrasound (I've attached the scans), and the vet who did them said she had internal pus (!!!), cysts in both kidneys (!!!) and this is his short report:

"Urinary bladder: cystitis with sedementation inside Kidney: Rt & Lt kidneys showed multiple cysts and the Rt. hydronephrosis

Liver: normal Gall bladder: normal

Conclusion: Internal pus and hydronephrosis in Rt. kidney Palycystic kidney"

What does all this mean?! The ultrasound vet assured me all this wasn't serious and was all treatable but the other vet said there was reason to worry and this meant her right kidney had failed and might not work again! I am soooo scared and worried and don't know who to believe. The vet put her on daily ringer drips and will give her glucose today, she's taking lasix shots, an antibiotic and other shots I don't know what they are (my vet isn't very talkative!). I've included her blood picture results that seem to be very bad. What do you think is happening to my dog - Samba? Is it a bad prognosis or do you think everything will be ok ? She's so young and we resuced her from the streets of Cairo when her mother was poisoned and killed (we have many strays here). One of the vets said it was hereditary? Is it? we have her brother and sister - should we be concerned about them now? She's now drinking less and her appetite is poor and her prescribed low protein diet isn't helping with her appetite much. Of course she urinates quite alot now due to the lasix. I am so worried Dr Michael, I love my dogs so much and they are the light of my life and would be devasted if anything happened to them, they are the only thing keeping me going in life...

Money, time and effort are no concern for me when it comes to my pets - do you think there are more tests or anything else that can be done?

Sorry about the long email but I wanted to explain everything as best as I could, I don't have access to all the tests and info I've seen other subscribers write about, veterinary medicine here is very different than in the US - we're quite backward and as I mentioned before diagnostic instruments are virtually non-existent - only the ultrasound ( very new here) and x ray machine - only one or two I know of here in Egypt and I was told they weren't used well (?).

Thank you kindly for your time and any advice/info you can give me on Samba's condition.

ps: the vet who did the ultrasound said the cysts could be sucked out(?) after they treat the pus if they don't lessen in size - is this a complicated proceedure? it is risky? if they are removed, do they return again? Any info would be greatly appreciated in this!

Answer: 

I am sorry for the delay in responding to your question. The IV fluids, diuretic (Lasix Rx) and antibiotics are the necessary first steps in treating the kidney disease affecting your dog. I tend to agree with the second vet who thought this condition was serious. Kidney insufficiency (chronic kidney failure) in dogs can be very difficult to stabilize for long periods of time. Cystic kidneys are not as common in dogs as they are in some cat breeds and I do not have much information on this disease in dogs. However, there do seem to be dogs that have this particular defect as a benign problem for much of their lives.

It might be worth asking your vets about the possibility of an ectopic (misplaced) ureter. This is one of the major causes of hydronephrosis and can sometimes be surgically corrected.

There are several anesthetic agents used in dogs and they vary widely in the amount of time the dog sleeps and the after effects. Some of the anesthetics are more likely to cause liver problems than others. It seems more likely that the kidney problems were already present and the recovery from anesthesia difficult to the kidney problem, though.

I wish I could help more but I hope it is reassuring that your vets do seem to be doing the right things and that you were able to obtain really high quality care for your dog, giving her the best possible shot at recovering. There is a chance even with the good work done so far that she could be in trouble, but I hope not.

Causes of Canine Kidney Failure 

Question:

Wolf, our 6.5 year old bichon frise is demonstrating symptoms of kidney failure. What are the possible causes?( Lab work forwarded). Are we missing anything? What do we do next.?

Answer:

Wolf's lab work does support renal failure from some cause. Weight loss, vomiting and increased drinking and urinating are symptoms often found with renal disease. In addition, the lab work is supportive of this diagnosis, particularly the increases in BUN and creatinine and the decreases in albumin levels. I'll try to answer your specific questions first and then give a more general overview of the potential kidney problems and ways of differentiating between them.

1) Are we missing anything? The first thought that came to mind for me was that continued monitoring of Wolf's ability to concentrate urine would be a good idea. This is easily accomplished by testing for specific gravity in urine samples. The ability to concentrate urine to a specific gravity of 1.030 in a dog is a pretty good indication that the kidneys are functioning better. The other thought is that there are lot of possible causes of this condition and that it may take a lot of work to figure out exactly which one is present -- and that you may or may not want to go through the process. A more costly test is a urine protein/creatinine ratio which can help in determining whether kidney disease is continuing to progress or is stable at the moment. A protein/creatinine ratio greater than 1.0 is bad, less than 0.6 is good.

2) Leptospirosis is definitely possible with the symptoms seen. It has to be included in a list of differential diagnoses and it is a good idea to initiate treatment while waiting on the lab results. Cancer is also possible but primary kidney cancers are not all that common in dogs so it is perhaps less likely.

3) I think it is a good idea to monitor urine concentrating ability for a long time after an initial unexplained bout of renal disease. It is an inexpensive test and I like to check urine specific gravity weekly for a few weeks, then monthly for a few months and then occasionally after that in dogs that have had a serious episode of renal disease.

4) Subcutaneous fluids are cold compared to body temperature and it is not unusual at all for dogs to shake or tremble (shiver, actually -- but it can look more like trembling in a dog) after administration of the fluids. Low potassium levels sometimes accompany renal disease and potassium levels below 3.5 mEq/L can cause muscular weakness. Pain can cause trembling and it is hard to figure out if there is pain in our canine patients, sometimes.

5) If Wolf was dehydrated prior to the tests it would influence the tests that are related to kidney function. Dehydration has the most effect on BUN but can affect creatinine as well. High protein levels are also commonly associated with dehydration. Therefore the correction of a dehydrated state could lead to decreases in BUN and creatinine, as well as other blood values. I don't think that this would completely explain the lab work in Wolf's case, though. The creatinine, in particular, is still high after treatment.

What to do next is the big question. It may help to review the most likely causes of Wolf's problem and the ways of differentiating between them.

Renal (kidney) failure can occur for a lot of reasons. It would be hard to compile a list that anyone would agree was a complete list of causes, due to the number of potential causes that exist. So this is a partial list:

Pyelonephritis, which is infection of the kidney itself

Congenital disorders, which are recognized to occur in the following breeds, according to Nelson and Couto, in their book "Essentials of Small Animal Internal Medicine" - Lhasa apso, shih tzus, Norwegian elkhounds, shar peis, Doberman pinschers, samoyeds, standard poodles,, soft-coated Wheaton terriers, cocker spaniels, beagles, keeshonds, Bedlington terriers, cairn terriers, basenjis and Abyssinian cats.

Renal hypoplasia or dysplasia - congenital but not always hereditary

anything that blocks urine from getting from the kidney out of the body - congenital urinary tract defects, large bladder or kidney stones, renal parasites, trauma, etc.

Immunologic disorders --- systemic lupus erythematosus, glomerulonephritis, vascular disorders, feline infectious peritonitis

Amyloidosis - a disorder that normally occurs in dogs over 5 years of age but can occur earlier is shar peis. It can occur for no apparent reason or it can be linked to underlying causes such as chronic infections (not necessarily of the kidney), chronic inflammation that isn't from infection, cancer, cyclic hematopoiesis in gray collies. It occurs for no apparent reason more commonly than it occurs due to discoverable underlying causes

Glomerulonephritis - inflammation of the glomerulus (the individual functioning units of the kidney). Can be due to a number of causes, including: bacterial infections {Lyme disease, brucellosis, other systemic infections}, viruses {infectious canine hepatitis, feline leukemia, feline infectious peritonitis, feline immunodeficiency virus, chronic feline upper respiratory virus infections}, rickettsial infections {ehrlichiosis, Rocky Mountain Spotted Fever}, heartworm disease, protozoan infections {trypanosomiasis, leishmaniasis}, cancer, chronic inflammatory conditions {pancreatitis, systemic lupus erythematosus, prostatitis, chronic skin disease, possibly periodontal disease}, hyperadrenocorticism, diabetes mellitus and finally hereditary disorders in Doberman pinchers, samoyeds, rottweilers, greyhounds, bernese mountain dogs, soft-coated wheaton terriers and cats.

Acute insults to the kidney - trauma, ischemia (lack of blood flow) due to {clots, low blood volume, shock, heart failure} and drug reactions or toxins {covered separately}

Leptospirosis

Hypertension (high blood pressure) -- from hyperthyroidism, chronic heart failure

Hypotension (low blood pressure) -- usually associated with shock

Hypoadrenocorticism (Addison's disease)

Cancer -- usually primary kidney cancer, lymphoma or spread of cancer (metastasis) from other sites

Unidentifiable causes

Toxins that are known to affect the kidneys: lead, mercury, arsenic (usually arsenicals used to treat heartworms), cadmium, chromium, thallium, ethylene glycol (antifreeze), carbon tetrachloride, chloroform, pesticides, herbicides, solvents, snake or bee venom, possibly mushrooms, vitamin D toxicosis from rodenticides

medications known to affect the kidneys sometimes: aminoglycoside antibiotics (gentamicin, amikacin), cephalosporins, polymixins, sulfonamides, tetracyclines, amphotericin B, thiacetarsamide (Caparsolate Rx), methoxyflurane anesthesia, non-steroidal anti-inflammatory medications (aspirin, acetaminophen, ibuprofen, phenylbutazone), many chemotherapeutic agents, gold salts, radiographic contrast agents

So there are a lot of possible causes of kidney disease. Reviewing the list can sometimes help in ruling out possibilities. If you suddenly remember changing the antifreeze or have been struggling with skin disease for awhile it may be important to be sure those things have been considered, for instance.

I will try to send some information on distinguishing between these possibilities in the next few day or so.

Leptospirosis (zoonotic)

Question:

Thanks for all the info about canine kidney problems. It has been very helpful. Here's a quick update on Wolf, our 6.5 year old bichon frise who was demonstrating symptoms of kidney failure.

Last night our vet called and told us that Wolf tested positive for leptospirosis. His levels were elevated for 2 of the 5 antibodies they tested for. The vet said specifically Wolf was exposed to grippotyphosa and pomona strains of lepto. Both can cause kidney problems, sometimes permanent, depending on the infection. It seems our vet was wise to get Wolfie on the amoxi immediately as a precaution. He was confident that, with the symptoms and test results, lepto was the cause.

We believe Wolf was eating squirrel poop while we were on walks (at first we thought he was chewing on acorns but then I saw what he was really eathing!) and Kay recently recalled that Wolf got to a dead squirrel that was hidden under some leaves. He may have munched on it once or twice before she yanked him away. I suspect either of these could be how he contracted lepto.

We are going to get some more specifics from the vet today but the vet said it would be a good idea to talk to our doctor/pediatrician about the possibility of Wolf passing the lepto to us or Jake (our 9 month old 2-legged furless son). He also recommended testing Glennis, Wolf's sister/littermate. Wolf will finish out his amoxi series (10 days total) and then go on a month of doxicyclin. After the amoxi we'll do some standard bloodwork looking for reduced urea nitrogen and creatinine, globulin level, protein levels, etc. Eventually we will need to retest Wolfie to confirm he beat the lepto, but the vet wasn't sure if that would be in a month, 6 months or what. He is going to get back to us today on that.

FYI, there is some good info on the net on leptospirosis. I can't remember the site address but using "leptospirosis" as the search word on Yahoo it hit only 3 sites that are all linked. Lots of good info.

Since we are now financial supporters (albeit very minor ones!) of your great website, I might as well ask a couple of quickie questions if you have time:

1) We live in Fairfax, VA, and I see you are just down the road. Do you see or hear much about lepto from other vets in VA? It seems to be relatively rare.

2) Our friend, a microbiologist in a pediatric lab, suggested we confirm with the vet that the elevated antibody levels were NOT caused by his vaccination against lepto which occurred in Mar 98. I would think, however, that the lab would be looking for a significant increase in the antibody level, more than that caused by a vaccination. We'll get the actual numbers today (hopefully), but any thoughts on that since you deal routinely with vet labs and are familiar with their procedures? Could this be a false result due to the vaccination in March?

3) Will we be able to tell from the lepto tests (antibody levels, type, etc.) how long Wolf

Get additional information on Leptospirosis in Dogs.


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Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...

 

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