CRF - Canine Renal Failure or Kidney Insufficiency

Treament programs to discuss with your veterinarian and what you can do at home.

Please note: the following are excerpts from many different web sites.  Where possible we have included links to the original sites, so that if that particular topic interests you then you can investigate it further.  We have not drawn any conclusions on this page, but merely laid out the information as we found it.  There is no organization to this page - but a lot of very useful information for any pet owners with animals that may be suffering from or are afflicted with CRF, Kidney Insufficiency, Hypertension, Pancreatitis, etc.  Please note that one of the sites quoted here gave us the modified diet for Natasha (it's near the bottom of the page). We hope you will find this information of value. Please send your comments to: Ron Conley, Web Master for Natasha's Cancer Fight Newsletter.


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The most basic part of treatment for canine renal failure is fluid therapy.  Aggressive fluid therapy early in renal failure (it is important to be certain the kidneys are at least producing some urine output before getting TOO aggressive) can make a big difference in prognosis. Even in chronic renal failure administration of fluids can be very helpful.


Angiotensin converting enzyme inhibitors (ACE inhibitors) are being used more frequently in renal failure patients to try to conserve protein in renal failure patients by limiting protein loss into the urine. Enalapril (Enacard Rx) is the most commonly mentioned ACE inhibitor for this effect.  These also help to control high blood pressure, which can be a side effect of renal failure. Calcitrol is being used more often in dogs to try to limit the problems with hyperparathyroidism that occur in conjunction with renal failure. This may help patients with renal failure feel better, at least. 


Potassium administration seems to help some dogs. If you are using one of the formulated diets for renal failure, such as Hill's k/d diet or Purina's NF diet it may not be necessary to supplement additional potassium, though. 


Phosphate binders help some dogs. These are over the counter medications, such as Amphogel or Basalgel (TM).  For some reason, though, I remember seeing a note that Amphogel was hard to find lately. 


If anemia is present with chronic renal failure it may be helpful to use erythropoietin injections or nandrolone to stimulate the bone marrow. The erythropoietin injections work better if there are not resistance problems with this medication. 


Medications to protect the stomach and intestines from irritation due to renal failure can be very helpful, as well. Cimetidine (Tagamet Rx) and famotidine (Pepsid AC Rx) are two examples of these kinds of medications. 


Hemodialysis is, or was at least, available at some sites in the United States, for dogs with chronic renal failure. Transplantation of kidneys, while somewhat common in cats, doesn't yet work as well in dogs and is not an option at this time, as far as I know.  (maybe some research is going on with this that could be tapped into). If there were a dialysis center near me and I could afford it, I would definitely consider this option.


Rimadyl (Rx) is new and is supposed to be effective in the treatment of arthritis on a chronic basis without the gastrointestinal and renal effects of other non-steroidal anti-inflammatory medications such as aspirin. All things considered, I think it would be my first choice right now. Like all new things, it is possible some unforeseen effect may occur but that is less likely with Rimadyl since it has been in use in other countries for some time.

Regarding use of Calcitrol, the phosphorous level should be controlled prior to the use of Calcitrol, if at all possible. I (Dr. Richards) have been somewhat confused by this issue, myself. The problem is that Calcitrol doesn't have as much effect on phosphorous as it does on calcium levels and parathyroid hormone levels.  Control of phosphorous is best done using low phosphorous diets and phosphate binders such as Amphogel and Basalgel. If the phosphorous level is above 6 mg/dl is best prior to starting Calcitrol. I don't think there is any harm in using Calcitrol when serum phosphorous levels are above 6 mg/dl but it may not be helpful in this situation.


There are veterinarians and veterinary specialists who feel that phosphorous restriction (through diet and phosphate binders) alone is sufficient in renal failure. This may be true. The proponents of Calcitrol seem very convinced that it makes patients with kidney failure feel better and live longer, though. 


Calcitrol does have a more significant effect on ionized calcium and total calcium, usually causing both to rise. It also should cause a decrease in parathyroid hormone levels because they rise in response to low calcium.


To make this all even more confusing, in renal failure the total calcium level will often rise due to metabolic changes. However, the portion of the calcium in the blood stream that is free for the body to use (the ionized calcium) will stay normal or low. This means that there are times when it appears that it would not be a good idea to use Calcitrol (when calcium is higher than normal) when in fact it would be beneficial (because the ionized calcium is low). Unfortunately, many vets do not have a reasonable way of measuring ionized calcium in their practices.


Measuring the phosphorous level every couple of weeks is reasonable when trying to get it to drop and stay at a level less than 6 mg/dl. Monitoring phosphorous and calcium is reasonable as often as monthly when using Calcitrol but this depends on financial resources. If money is limited, monitoring less often is probably OK. Monitoring parathyroid hormone levels is also useful (they should drop if the Calcitrol is working for the patient). However, this is also an additional expense and again the financial impact has to be considered. In practices that use some in-house blood analyzers it may be necessary for the practice to run a whole panel to get one result. This is a drawback of some machines. I don't see a reason not to use an outside lab and request just the lab values necessary, though. In this case, instant turn-around on lab results isn't really essential.


Calcitrol is not going to make renal failure go away. If it does all that it is supposed to do it will make the patient feel better and live longer. These are significant benefits but they are subjective things and you have to remember that they are comparisons to pets with renal failure not getting Calcitrol --- not comparisons to normal dogs! Feeling better is a relative thing. (Kidney Transplantation)
Anemia of CRF is no regenerative, normocytic and normochromic. It is caused by deficiency of erythropoietin releasing factor, erythroblast inhibition, reduced survival of RBC, iron deficiency (blood loss, impaired absorption), myelofibrosis, chronic infection, or loss due to coagulation abnormalities.


Coagulation abnormalities arise from abnormal function of normal numbers of platelets which is called thrombocytopathia.


Sodium handling by diseased kidneys: The kidneys still try to maintain sodium balance by excreting excess or conserving in states of limited intake. Each nephron must excrete more sodium to maintain balance and there is a narrower range of response which leads to an inability of the chronically diseased kidney to adapt to rapid changes in sodium intake (increases or decreases).


Blood pressure: Renal failure patients are often hypertensive. Hypertension is defined as a systolic pressure > 180 mmHg (dog) > 200 mmHg (cat) and a diastolic pressure > 95 mmHg (dog) > 145 mmHg (cat).


Blood pressure can be measured by indirect techniques using oscillometric or doppler methods from the cranial tibial/dorsal pedal artery, metacarpal artery or the coccygeal artery. Indirect readings are comparable to direct measurements obtained by arterial puncture.


Blood pressure monitoring equipment is not uniformly reliable in dogs and cats. Several readings should be obtained to confirm consistency of the measured values.

Doppler blood pressure unit - measures systolic pressure only


Dinamap oscillometric blood pressure and inflatable cuffs for Dinamap. The cuff size must be appropriate for the size of the patient or the readings will be inaccurate.

Normal blood pressure in dogs (direct technique)


     148 + 16 mmHg systolic
     87 + 8 mmHg diastolic
     102 + 9 mmHg mean


Normal blood pressure in cats (direct, awake, 5-10 mmHg lower under anesthesia)


     171 +/- 22 mmHg systolic
     123 +/- 17 mmHg diastolic
     149 +/- 24 mmHg mean


50-93% of dogs with renal failure are hypertensive. 80% of dogs with glomerular disease are hypertensive. Hypertension may play a role in the self perpetuation of renal failure. Hypertension can also cause cardiac disease, CNS dysfunction and retinal detachment leading to blindness.


Factors which contribute to hypertension include:

     failure to excrete salt and fluid
     stiffening of venous capacitance vessels
     altered adrenergic activity
     activation of renin-angiotensin-aldosterone system
     suppression of renodepressor prostaglandins


Other ionic disturbances may be present including an increase in magnesium which can cause drowsiness and increased neuromuscular excitability. Potassium is variable depending on urine output, dietary intake and gastrointestinal losses but is usually normal or low in polyuric CRF.

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 erythematosusglomerulonephritis, 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, pesticidesherbicides, 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. (Mike Richards, DVM)

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. Glomerulonephritisamyloidosis, polycystic renal disease (more common in cats), pyelonephritis, cancer, viral and bacterial infections, hypertensionhypotension 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.


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 your pet 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. (Columbia Animal Hospital)

The key to ongoing CIN treatment takes place at home, where owners can take several steps to help their dogs. Make sure a dog with CIN always has access to fresh water. To encourage the dog to drink and eat, maintain a steady, stress-free daily routine. (Stressed-out dogs often stop drinking and eating, further jeopardizing kidney function.)


Dietary management can also help your dog. This consists primarily of restricting the amount of protein, phosphorus, and sodium in the diet, while providing adequate amounts of non protein calories, vitamins, and minerals. But not every dog with kidney disease needs such a diet.


Renal Failure Diets-(these are some suggestions-but your veterinarian may have others)


     Diet                      KCAL                 Protein


     HILLS                350KCAL/CUP        12.7%

                              612KCAL/CAN        13.2%


     SELECT-CARE  362KCAL/CUP        12%

                              525KCAL/CAN        13%


     CNM-NF            415KCAL/CUP        12%

                              516KCAL/CAN        11.7%


     CNM-CV            638KCAL/CAN        12.3%


     HILLS UD           791KCAL/CUP          8%

                              662KCAL/CUP         7.9%


     WALTHAM         390KCAL/CUP



Homemade diets: Cooking instructions


Mix the rice, calcium carbonate, corn oil and salt. Cook according to instructions for the rice.  Add remaining ingredients except the vitamins .  Simmer 10 minutes and cool.  Add vitamins before feeding.


?        7% Diet: 1068 KCAL

3/4 cup raw rice; 1 large egg; 1 oz. liver; 3 Tbsp. bacon fat; 1 tsp. corn oil; 3/4 tsp. calcium carbonate (Tums); 1/4 tsp. iodized salt


?        12% Diet: 1145 KCAL

2/3cup raw rice; 2 large eggs; 1/3 cup low-fat cottage cheese; 1 oz. liver;  3 Tbsp. bacon fat;   1tsp corn oil; 3/4 tsp. calcium carbonate Tums); 1/4 tsp. iodized salt.


?        16% Diet: 1119 KCAL

2/3 cup raw rice; 1/2 cup diced poultry; 1/3 cup low-fat cottage cheese; 1 oz. liver; 3 Tbsp. bacon fat; 1 tsp. corn oil; 3/4 tsp. calcium carbonate (Tums); 1/4 tsp. iodized salt.


Approximate feeding recommendations: Please check with your veterinarian.


Body wght (LB)   

Approx.- KCAL/Dy   

Can - Dry



1/3    -     3/4



2/3    -  1 1/4



1       -       2



1 1/3  - 2 3/4



1 2/3  - 3 1/2



2        - 3 1/2



2 1/4   - 4 3/4



2 1/2   - 5 1/2



2 3/4   -       6



3         - 6 1/2



3 1/3   -       7



3 1/2   - 7 1/2



3 3/4   -       8



4         - 8 1/2



4 1/2   -       9



5         - 9 1/2


Studies suggest that feeding your dog a diet low in phosphorus may help slow the progression of kidney failure by reducing mineral deposits in the kidneys.  And while there’s no conclusive proof that low-protein diets slow CRF in dogs, your pet may feel better on such a diet. Low-protein diets generate fewer nitrogenous wastes - high levels of which can cause nausea and vomiting in dogs with kidney disease. A cautionary note: low-protein diets, if not carefully managed, can lead to malnutrition. So be sure to consult your veterinarian before making any such dietary changes.


Above all, keep a watchful eye. Report any changes in your dog’s eating, drinking, and elimination habits to your veterinarian. Such changes may alert your veterinarian to the possibility of kidney disease - or help your practitioner adjust treatment if therapy has already begun.


With kidney disease, your dog becomes less alert, loses its appetite, and may vomit. Take your dog to your veterinarian if it shows any of the following signs that sometimes (but not always) point to kidney disease:


Chronic Failure

1.      Increased thirst and urine volume

2.      Weight loss

3.      Weakness and exercise intolerance

4.      Tendency to bleed or bruise easily


Acute Failure

1.      Dehydration (To test for this, gently pull the skin away from your dog’s middle. If the skin does not immediately spring back, the dog may be dehydrated.)

2.      Stiff-legged gait and arched back (a sign of painful kidneys)

3.      Little or no urine production

Other Helpful Links: (Holistic Vet) (Holistic Vet) (Martha S. Gearhart, DVM) ( Vet Info)


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This page was last updated on December 8, 2006

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