Greyhound Gang - Medical

Kidney

Greyhounds can be misdiagnosed with kidney issues, because their CREAT and BUN levels run higher than other dogs. Please give your vet a copy of Dr. Stack the Deck for Greyt Health, or print out the Bloodwork information on our site to give to your vet.

If you truly have a hound with kidney disease, diet and proper supplements can help. Good proteins are good, when phosphorous levels are low. Milk Thistle and other supportive supplements for the kidney and liver can help too. Here are some links with information:

Yahoo Group List for Kidney/Dogs - people sharing information

Animal Medical Centre of Medina - wonderful articles

Susan Fleisher's Kidney Disease web site - very comprehensive

From: Stacy Pober
Subject: Medical, DOGCARE: Dog Food/Protein %

From: "harobeda@netzero.com" <harobeda@NETZERO.COM>
Does anybody know why some senior dry food contains a high percentage of protein such as 28% and some as low as 18%. I'm really confused as to which is best. I have read that low (18%) protein is best because too high is a strain on the kidneys. If so, why would some companies make it with 28% protein. Anybody knowledgeable in this? Please and thank you.

You want the long story or the short?

Short:
High protein does not harm or wear out the kidneys. Old dogs' bodies have to do more cellular repair, and that's why they need moderate to high protein levels. Older dogs tend to digest things more poorly, so they do better on a good quality protein source, one that is easily digestible

Long:
In the old days (say 20 years ago) the recommendation was to limit protein on old dogs because of possible kidney harm. But they had not done studies to validate this recommendation - it was based on studies of *other species*.

When they finally got around to doing dog studies, it was found that not only did high protein not hurt the kidneys, but dogs with damaged kidneys lived LONGER on high protein diets.

It turns out that the major nutrient that harms kidneys is phosphorus. Phosphorus is present in most muscle meat, so many high-protein diets were also high in phosphorus. But it is possible to design a low-phosphorus, high-protein diet, and that is what is in the better senior foods.

I did a survey on phosphorus levels in commercial kibble a couple of years back. I have not updated this, so call the manufacturers if you want to check on the current stats. The article, with links to veterinary articles on kidney function and diet is on my website.
Best,
Stacy
Golightly Greyhounds
roo@raingoddess.com

From: Stacy
Golightly Greyhounds
http://www.raingoddess.com/

The old theory of nutrition and renal failure was that high protein "wears out" the kidneys. It turns out this was a false assumption, based on research done in other species. For dogs, all of the recent veterinary research about kidney failure has shown that high protein intake does not harm the kidneys of dogs in renal failure.

In fact, there's some research indicating that restricted protein diets can be harmful to dogs with impaired kidney function.

An article from 1998 Purina Nutrition forum specically on this issue is available online. It's: "Mythology of Protein Restriction for Dogs with Reduced Renal Function" by Kenneth C. Bovee DVM, MMedSc. http://www.vetshow.com/download/purina/finco.pdf

Here's some excerpts from Dr. Bovee's article:
"there is evidence that high protein diets enhance renal function in normal dogs. This has led to confusion among veterinarians who have been told for decades that low protein diets may be beneficial for kidney function and therefore high protein diets may be deleterious to normal dogs."

"Because of the confusion in the veterinary literature and the lack of evidence to support the use of reduced protein diets, a number of experimental studies have been performed in recent years. These studies have utilized the standard experimental model of reduced renal function and have addressed many questions when dogs received varied forms and
quantities of protein at different levels of renal function. [...] Results of the 10 experimental studies on dogs have failed to provide evidence of the benefit of reduced dietary protein to influence the course of renal failure."

"Based on the previous data, the only advantages [of dietary protein restriction in dogs] appear to be a lowering of BUN and the possibility of reduced nausea. Quantifying the value of these effects has not been reported in dogs. On the contrary, there appear to be disadvantages to reduced protein intake. These include reduced kidney function as
measured by GFR [glomuleral filtration rate] and renal plasma flow, possibility of a negative nitrogen balance, and the promotion of a catabolic state in the presence of proteinuria."

If you'd like to read a review of the current studies on this, there's a good summary in the article: "Effects of Dietary Protein Intake on Renal Functions" by Delmar R. Finco in Purina Nutrition Forum 1998. This is available online at: http://www.vetshow.com/download/purina/finco.pdf

In part, Dr. Finco states:
"When attention is focused on those experiments in which protein has been isolated as the only variable, the data are overwhelmingly indicative of a failure to demonstrate a protein effect on the functional or morphological deterioration of kidneys of "remnant kidney" dogs."

He has a table summarizing the various studies. In some of the studies, the diets varied in other components as well as varying in protein. But of the studies that varied ONLY the protein, there were no differences noted in kidney function in the different study groups.

One study had dogs with 15/16ths of their kidneys removed on diets of either 16% or 31% protein for 24 months and the result was: "No differences in deterioration of renal function or in severity of renal lesions." (Finco, DR, Brown, SA, Crowell WA, et al: Effects of dietary
phosphorus and protein in dogs with chronic renal failure. Am. J. Vet. Res. 53:2264-2271, 1992.) Another study had diets of 14% or 40% protein fed to dogs who had 11/12ths of their kidneys removed. They were fed these protein levels for 100 weeks. The result: "No functional deterioration with time with either diet; no difference in severity of
renal lesions between diets." (Polzin DJ, Osborne CA, O'Brien TD, et al: Effects of protein intake on progression of canine chronic renal failure (CRF). Proceedings of the 11th Annual Veterinary Medical Forum, 938, 1993.)

So what should people feed their dogs with renal failure? Restricted phosphorus diets, for one thing. Restricting phosphorus is one dietary change that has been shown to prolong the lives of dogs in renal failure. Aside from restricting phosphorus intake, phosphorus binders can be used to prevent absorption.

Most commercial 'kidney diets' such as k/d were low-protein because that was the old theory. Now that low protein is counter-indicated in early stage renal disease, what DO you feed? Well, the problem is that most higher protein foods are also higher in phosphorus. Dairy and eggs are relatively low phosphorus considering their protein content and can be added to senior or 'kidney' diets to help boost protein levels.

A Fall 1999 article on Nutritional Management of Dogs and Cats with Chronic Renal Failure by Dr. Tina Kalkstein, a board certified veterinary internist. (Her portrait on this site shows her on the beach with a brindle, a fawn, and a black greyhound, btw.):
http://www.southpaws.com/news/99-2-nutrition-CF.htm

"CRF patients should be fed the maximal amount of protein they can tolerate until clinical signs of uremia develop. Once this occurs, the protein intake should be tailored to meet the needs of the patient. If the dog or cat loses weight, coat condition, or serum proteins on a low protein diet, but feels otherwise good, consider adding additional protein to their daily meals (egg, cottage cheese, tofu, etc.) or choosing a different diet that is less protein restricted until finding the individual's tolerable threshold of protein intake. Acid-base status should also be monitored and corrected as needed (adding bicarbonate to the drinking water is a simple way to manage mild to moderate acidosis).
Phosphorus levels are important to monitor and manage as well."

Excerpt from Iams Nutrition Symposium (May 1998):
http://www.eukanubacatfood.com/vet/symposium/building/building.html

"For decades, without scientific validation, veterinarians have attempted to decrease nitrogenous waste products by simply limiting the protein substrate; low-protein diets have been a staple in the nutritional management of chronic renal failure patients. However, recent studies by Dr. Gregory A. Reinhart and fellow Iams nutritionists show that restricting protein may do more harm than good. "Excessive restriction of protein," he said, "puts many companion animals at risk of protein malnutrition." Also, carnivores find low-protein diets less than palatable, especially animals already nauseous and anorexic from renal failure. Iams' research shows not only that optimal protein levels do not harm the kidneys, but that they benefit the patient by maintaining muscle mass and increasing energy."

"Defining "optimal" is the challenge. Dr. Reinhart said veterinarians need to "match the level of protein restriction with the stage of disease progression" in what he termed a "nutritional balancing act." Clinical trials by Dr. Mark A. Tetrick, Iams Veterinary Nutritionist, have indicated that dogs in early chronic renal failure may be successfully fed approximately 50 percent more protein than is found in conventional renal diets. Dogs with advanced renal failure can safely be fed approximately 25 percent more protein. The dogs fed the higher protein diets looked better, based on coat condition, and had no adverse serologic effects. Their blood urea nitrogen (BUN) levels remained the same or went down, and their triglyceride levels actually fell. Dr. Tetrick also found that blood phosphorus levels went down as a result of the extremely low phosphorus content of these diets. Phosphorus restriction has been shown to slow the progression of renal disease."

Here's some of the current recommendations from Ohio State's vet school
http://nss.vet.ohio-state.edu/Vm%20720/Nutrition%20and%20Chronic%20Renal%20Failure.html

"Results of recent research are changing our recommendations for nutrient modification in dogs with early signs of CRF. Restricting phosphorus intake to about 30 mg/pound/day as soon as polyuria is recognized, and supplementing potassium intake (with alkalinizing salts if acidosis is a concern) to maintain serum potassium within the normal range may be all that is necessary until patients develop severe disease. Diet change or phosphorus binders, such as aluminum hydroxide, calcium carbonate, or calcium acetate may be used to restrict phosphorus absorption. Phosphate binders and potassium supplements can be added to the diet in small amounts initially, and increased as the patient's tolerance and condition permits."

Sodium restriction may be beneficial to animals suffering systemic hypertension, but should be introduced gradually. Animals with CRF have lost most of their renal reserve capacity, and cannot quickly adapt to large abrupt changes in nutrient intake. Modification of the fatty acid composition of diets to reduce the n-6 to n-3 fatty acid ratio also may be beneficial, and studies to address this point currently are in progress.

Hope this helps. I lost a dog to renal failure and I know how heartbreaking it can be. There's not much you can do in the way of treatment outside of dietary management, so it's very frustrating to realize (as I did) that the perfectly nice vet you're using had probably not read a vet journal article on renal failure and diet in the last 10 years, so he was recommending that we do something less than useless.

If I had a dog with renal failure today, I'd probably buy the highest protein of the current renal diets - I know that Iams touts theirs as being higher than most. I'd add protein from relatively low-phosphorus but high quality sources like cottage cheese if the dog seemed hungry all the time or did not find the food to be palatable on its own.

Best,
Stacy
Golightly Greyhounds
http://www.raingoddess.com/

<< There are three types of renal disease. Acute Renal Disease, Chronic Renal
Disease and Inherited Renal Disease.

ACUTE RENAL DISEASE is a kidney disorder that occurs suddenly. Possible causes include bacterial infections, drug toxicities form substances such as gentamiacin, or poison such as antifreeze. Regardless of the cause the
kidneys rapidly lose the ability to function properly.    Many symptoms of renal disease are caused by toxic nitrogen levels in the bloodstream and is referred to as uremia. Signs of uremia include mouth ulcers, vomiting, seizures, diarrhea, bleeding disorders and depression. Diseased kidneys cannot conserve normal amounts or water nor can they excrete excess nitrogen. Body fluids are lost causing dehydration.     Any kidney disorder is considered serious but because most cases of ACUTE renal disease have known causes treatment is usually successful. Once
the cause has been identified IV fluids may be necessary to flush out the kidneys.

CHRONIC RENAL DISEASE often has no identifiable cause. It is generally related to aging and is a simple deterioration and loss of filtration area within the kidney. These areas are called glomeruli. When a significant
proportion of the glomeruli die or a re injured there may not be enough left to remove normal wastes from the bloodstream, therefore toxic levels of these substances develop within the body. The kidneys can no longer
conserve water so abnormally large amounts of urine are produced and water is lost from the body.     Unlike acute renal disease the signs of chronic renal disease develop slowly over time. Because the kidneys can no longer conserve water there will be increased urination both in frequency and volume. In an effort to compensate and keep the body hydrated the patient will consume larger quantities of water.   In the early stages of the disease the nitrogen levels may or may not be elevated in the bloodstream. Kidney can lose over 75% of their function
before they are no longer able to detoxify the body. In addition to uremia mouth ulcers may develop as well as weight loss, muscle wasting, poor appetite, depression, bleeding disorders, increased thirst and urination
and possible seizures. There may also be a decreased production of red blood cells, thereby creating anemia.
    Most cases of chronic renal disease and failure are not reversible. The kidneys have simply worn out. Low protein diets may help reduce the nitrogen intake therefore reducing the work load of the kidneys.

INHERITED RENAL DISEASE frequently affects patients 5 years of age and younger. Unlike Chronic renal disease in older patients it is not a degeneration of the kidney tissue, but a failure of the kidneys to develop and mature normally. Inherited Renal Disease has been very well documented, especially in the following breeds: Rotties, Samoyeds, Beagles, Mini Schnauzers, Shih Tzu, German Shepherds, Dobermans, Chow Chows, Carin Terriers, Bulldogs, Elkhounds and Std Poodles. Individuals from any breed may be involved but the listed breeds are the most commonly diagnosed.
     The symptoms are the same as patients suffering from Chronic Renal Disease however the age of onset is much younger. Patients with Inherited Renal Disease fail to thrive and live shorter life spans and severely affected dogs usually die before one year of age.    THERE IS NO CURE FOR INHERITED RENAL DISEASE. Low protein diets are fed
to help decrease the work of the failing kidneys.    Patients with a history of inherited renal disease should NEVER be utilized in a breeding program. A careful evaluation of the history of the parents, grandparents and siblings should be considered. Animals with a history of producing offspring with inherited renal disease should not be
bred again.   As an aside a high protein diet maybe harder for failing kidneys to deal with but high protein diets do NOT cause renal disease.

   I am not a vet and the above is a compilation of all the information I have found. If any of the vets can add something or if I'm off base on anything please say so. I'd be interested in hearing any other information.

***********************
<< Subj: Creatinine

The creatinine level is supposed to be the most specific indicator of kidney function. Unfortunately, it is not an early warning type of indicator. Once a dog's creatinine level rises over normal, 75% to 80% of the kidney function has already been lost.

An earlier indication of kidney problems is via a urinalysis. In the past, I had done blood panels every year or so on my old ones. Since realizing that this won't show kidney problems until they are pretty far along, I'm planning to run a urinalysis on them every year. The urinalysis shows dilution, protein in the urine, bacteria, (sugar?) and I can't remember what else.

An important thing to know about tests for kidney function (both urine analysis and blood tests) is that they don't show impaired kidney function until the kidney has lost at least 75% of its function. So your dog may be living with 70% of his kidney not functioning and the tests will say he is fine.

Why does it matter ? Because certain things like anesthesia and some very high dosages of antibiotics can damage kidneys. If the dog has already lost 70% of his kidney function and it is further damaged, he can end up without enough kidney function to survive.

Also when a dog is drinking increased amounts of water, kidney tests don't mean that the kidneys are fine. It just means that there is at least 25% of function left. So dogs can have impaired kidney function and high water intake long before kidney failure shows up on the lab tests.

Most owners assume that lab tests that show normal kidney function mean 100% of the kidney is working, and that is misleading. All the normal tests show is that the kidney function is somewhere between 25% and 100% of full function.

>From: karen peck <fastdogs@VERIZONMAIL.COM>
>I need your help and/or ideas. My senior girl Carly has >recently been diagnosed with kidney disease. You may remember her from a little over a year ago as one of two greys that >was abandoned(tied to a mailbox post}. I need some ideas >on what to feed her. She is currently on Hill's Canine k/d diet. What else, in addition to this is safe to feed? I am
>concerned about her weight as well. She is now at 47 lbs. >When she first came to live with us 16 months ago she weighed in at 57 lbs. I need some ideas on how to fatten up this old girl (she's now 10 1/2) who's on a low protein diet.

I've posted about this before, and I'd recommend you do an archive search on the list for the full story (and some debate) about this.

But in short, during the last dozen years or so, a lot of research into dogs and renal failure and diet was done that basically upended one of the previous theories.

Vets used to tell you to feed low protein diets to dogs in renal failure. However, that was not based on dog studies, it was based primarily on the fact that HUMANS with failing kidneys did best on a low protein diet. Turns out that dogs in kidney failure lived LONGER with more protein. Some studies used surprisingly high protein content - more than you'll
find in any commercially sold diet designed for dogs in renal failure. (If you're interested in reading the research, it's up on the web, and I put the citations to that in previous posts. Check the greyhound-l archives.)

So you don't necessarily have to restrict protein in the diet of a dog with kidney failure. But you DO need to restrict phosphorus. The single most important dietary change you can make for a dog in renal failure is to switch him or her to a low phosphorus diet. The longevity for dogs with compromised kidney function in studies was related to their dietary
phosphorus intake. Less phosphorus = longer life (statistically anyhow - obviously there will be individual differences.) Since meat is relatively high in phosphorus, formulating a diet that is low in phosphorus but high in protein is a bit of a challenge and probably rather expensive. Which explains part of why the commercial kidney failure diets tend to be low protein even in the face of the recent research showing this may not help things.

Some (though not all) dogs with kidney problems will be more comfortable and have more appetite on a low protein diet because their Blood Urea Nitrogen (BUN) level is high. One of the differences chemically between protein and other types of food (fats, carbs) is that they have nitrogen. So the breakdown of protein in the body leads to nitrogenous waste in
the blood. Healthy kidneys clear this easily, but diseased kidneys may not. When one of my dogs had this problem, I corresponded with a lady whose brother dies of kidney failure. She mentioned that as her brother's conditioned worsened, he would complain that the food all tasted soapy or "off" even though she had freshly prepared it in clean
dishes. This explained why my dog looked hungry yet would take the food in her mouth and then drop it.

There's more than one reason that your dog may be losing weight. She simply might not like k/d. She wouldn't be the first dog to think it was not very appealing. Or she might feel ill and may not be eating from that reason alone. If you've done a recent blood panel or at least run a creatinine and BUN level and the numbers have not risen since the time when she had good appetite, then maybe she's just bored with the Hill's prescription diet. If that's the case, you may have good luck simply by switching to another brand of prescription diet.

Many other manufacturers make "prescription" foods. Triumph, Iams/Eukaneuba, Purina, and several other major dog food manufacturers have prescription diet lines. Triumph's is sold OTC at some pet supply places. The others must be ordered through a vet, but the local distributors for some of these brands said they would sell as little as one bag to a vet, so he doesn't have to "switch brands" just to buy one for your dog. And some of the natural food/home cooking books have home-prepared kidney diets. I wouldn't completely trust the home diets to be low phosphorus unless the book was published in the last 10 years,
however.

If you want to add some protein to the prescription diets, you can look at the relative phosphorus levels of foods on some websites devoted to feeding humans with kidney failure. And if you want to compare phosphorus levels on the senior or prescription diets, it starts getting a little complicated. Get your calculator out because you'll have to compare the phosphorus per 100 calories to get a true comparison. The amount a dog eats is generally determined by the caloric density of the food, so you can't simply compare percentages of phosphorus. A seemingly low phosphorus food may be higher in phosphorus on an "as fed" basis as a result of this.

Okay, probably more than you wanted to know, but...

Good luck,
Stacy