RenAvast™ for Kidney Disease: Sloppy Science and Snake Oil Marketing

A reader recently asked me to investigate yet another supplement product, this one marketed for treatment of kidney disease in dogs and cats. While there are thousands of such products, and a thorough investigation of each isn’t possible, there were some interesting features to this particular product, so I spent some time looking into it.

What Is It?

The short answer is, “Who knows?” The product is called RenAvast™, and first on the list of red flags of quackery is the fact that the company won’t say exactly what it contains. The ingredients are listed as “a proprietary combination of amino acids and peptides.” While I understand that intellectual property concerns are often valid, it is also appropriate to be extremely wary of any medical therapy that contains secret ingredients. The American Veterinary Medical Association (AVMA) Principles of Veterinary Medical Ethics specifically identifies selling or using such products as unethical:

It is unethical for veterinarians to promote, sell, prescribe, dispense, or use secret remedies or any other product for which they do not know the ingredients.

I did find one site purporting to have identified the ingredients as, “300mg: L-Aspartic, L-Carnosine, L-Glutamic Acid, L-Glutamine, Glycine, L-Arginine, L-Histadine,” though I have not been able to confirm that on any site associated with the company. The inventor of the product describes it in a radio interview as “amino acids and a peptide,” but again doesn’t provide any more details.

The company research report describes the substance as:

a powerful ROS scavenger, a cytoprotective agent which reduces damage to proximal renal tubules and increases glomerular filtration rate (GFR), stimulates gluconeogenesis and suppresses proteolysis in skeletal muscle, has strong anti-inflammatory properties, is a precursor for NO production, and induces BMP-7…

It is impossible to assess these claims without knowing what the ingredients actually are. Elsewhere in the document, reference is made to seven different “biomolecules” in the product and their supposed functions. The claims made here for these functions are supported with a reference to an unnamed publication listed in the references as “PLAW 104-294.” I have no idea what this means.

There is reference to another study which showed that the molecule BMP-7 has some effect on damaged kidney cells in mice with artificially induced renal failure. Supposedly, biomolecule 7” in RenAvast™ induces production of BMP-7, though no evidence for this is provided. This tenuous connection between the mystery ingredients in RenAvast™ and kidney disease hardly justifies using the product in actual patients in the absence of additional pre-clinical research and clinical trials.  As we will see, there really aren’t any such trials.

The company makes many bold claims for the product despite the lack of tangible support for them:

RENAVAST™ MECHANISM OF ACTION

Protects cells, particularly in renal tubules.

Increases glomerular filtration rate (GFR).

Increases gluconeogenesis.

Decreases protein breakdown, especially in skeletal muscles.

Has a strong anti-inflammatory effect.

Decreases renal blood pressure.

Increases renal vasodilation.

Increases hormone that promotes renal tissue repair.

[RenAvast™ is] SAFE – More than 4,000,000 doses have been given to dogs and cats with no negative side effects reported… It is 100% safe with no side effects.

[It is] scientifically proven in an open-ended two year clinical study to supplement and promote healthy renal function. Unlike other products and drugs, RenAvast™ does not treat the symptoms of renal failure, it treats the cause.

Along with these confident claims is, of course the required Quack Miranda Warning which reminds us that the company has not felt it necessary to provide the FDA with any real evidence to support them: “These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.” It always amazes me that companies put this disclaimer on their sites and then loudly (and illegally) proclaim that their products do treat disease.

The chutzpah necessary to do this is especially impressive in this case since the company, BioHealth Solutions, has already been warned by the FDA that their marketing of RenAvast™ is illegal:

 

WARNING LETTER

August 1, 2012

This letter concerns your firm’s marketing of the product RenAvast™.  The U.S. Food and Drug Administration (FDA) reviewed your website at the internet address www.RenAvast™.com, where you promote and sell this product.  We have determined that RenAvast™ is intended for use in the mitigation, treatment, or prevention of disease in animals, which makes it a drug under section 201(g)(1)(B) of  the Federal Food, Drug, and Cosmetic Act (the FD&C Act) [21 U.S.C. § 321(g)(1)(B)].  Further, as discussed below, this product is an unapproved new animal drug as defined by the FD&C Act and your marketing of it therefore violates the law.

Statements on your website that show these intended uses of your product include, but are not limited to, the following:

• RenAvast™™ can halt the progression of chronic renal failure
• RenAvast™™ may reverse the effects of chronic renal failure
• RenAvast™™ may help prevent kidney disease in healthy cats
• RenAvast™™ is a new, highly effective compound that has been proven through a two-year clinical study to halt the progression of Chronic Renal Failure (CRF) in cats and improve overall kidney function
• Unlike other products and drugs, RenAvast™™ does not treat the symptoms of renal failure, it treats the cause
• RenAvast™™ was highly successful in halting the progression of Chronic Renal Failure and in most cases improved kidney function.
• Finally a solution for cats with Chronic Renal Failure
• A two-year open ended clinical study proves that RenAvast™ can halt the decline in kidney function
• Until now, veterinary medicine could only manage symptoms in an attempt to maintain quality of life while the disease progressed relentlessly onward. All of that has now changed
• Chronic Renal Failure is no longer a death sentence

Because RenAvast™ is intended to mitigate, treat, or prevent disease in animals, it is a drug within the meaning of section 201(g)(1)(B) of the FD&C Act. Further, this product is a new animal drug, as defined by section 201(v) of the FD&C Act, [21 U.S.C. § 321(v)], because it is not generally recognized among experts qualified by scientific training and experience to evaluate the safety and effectiveness of animal drugs, as safe and effective for use under the conditions prescribed, recommended, or suggested in the labeling.

To be legally marketed, a new animal drug  must have an approved new animal drug application, conditionally approved new animal drug application, or index listing under sections 512, 571, and 572 of the FD&C Act [21 U.S.C. §§ 360b, 360ccc, and 360ccc-1].   RenAvast™ is not approved or listed by the FDA, and therefore the product is considered unsafe under section 512(a) of the FD&C Act, [21 U.S.C. § 360b(a)], and adulterated under section 501(a)(5) of the FD&C Act [21 U.S.C. § 351(a)(5)]. Introduction of an adulterated drug into interstate commerce is prohibited under section 301(a) of the FD&C Act [21 U.S.C. § 331(a)].

This letter is not intended to be an all-inclusive review of your products and their promotion.  It is your responsibility to ensure that all of your products are in compliance with the Act and its implementing regulations. Failure to promptly correct the violations specified above may result in enforcement action without further notice. Enforcement action may include seizure of violative products and/or injunction against the manufacturers and distributors of violative products.

You should notify this office, in writing, within fifteen (15) working days of the receipt of this letter of the steps you have taken to bring your firm into compliance with the law. Your response should include any documentation necessary to show that correction has been achieved. If corrective action cannot be completed within fifteen (15) working days, state the reason for the delay and the date by which the corrections will be completed. Include copies of any available documentation demonstrating that corrections have been made.

Unfortunately, as I’ve discussed previously, regulatory control of veterinary quackery is not very effective. This warning appears to be more than a year old, and I was not able to find any information regarding how it was resolved. Regardless, the company continues to make clear treatment claims despite the warning and disclaimer.

 

Does It Work? Is It Safe?

The general claims about mechanism of action cannot be evaluated without any information about what is in the product. If there is any plausible reason to think it might work based on in vitro or lab animal studies, we cannot determine this without knowing what is in it.

Likewise, the safety cannot be assessed simply by accepting the company’s word for the fact that they have sold lots of it and no one has told them about any problems. All that I can say with certainty is that no medical therapy with any benefits at all is “100% safe,” so this is clearly nothing but marketing hyperbole. Such claims are a hallmark of snake oil therapies.

It is possible, however, to evaluate the claim that RenAvast™ is “scientifically proven.” I’ve talked before about what that means, and it is a good deal more complicated than the promoters of this product seem to understand.

The “research” that the company promotes as evidence RenAvast™ is safe and effective is a classic example of sloppy science used as a marketing tool rather than real scientific research. Information about the study can be found in a summary on the Bio Health Solutions web site and also a more detailed report which was previously made available online by the company and then apparently taken down, but which is available through a web archive.

19 cats with CRF were enrolled in an open ended 2-year study… All cats enrolled were diagnosed by their veterinarians with Chronic Renal Failure. None were on restricted diets. None were receiving fluids. All received 300 milligrams of RenAvast™ two times per day. All had periodic blood work…

There is no information about the cats, how they were selected, how long each was given the product, what other disorders most might have had, or any other details about the population studied or how the study was conducted. It is stated that the cats were enrolled “over a two year period,” but it isn’t clear how long each subject was treated and when or how often bloodwork was measured. Without this information, a huge number of possible errors and confounders could be present.

It is also not clear how the diagnosis of kidney disease was made. Two of the cats appeared to have a urine specific gravity of >1.035, which by the most common standard would not qualify them for a diagnosis of kidney disease. This critical value was not measured in three other cats, all of whom had near normal creatinine levels. This means at least 5/19 (26%) cats cannot be definitively said to even have had kidney disease at the start of the study!

Most cats showed little change in the various parameters measured, though again it isn’t clear how long each subject was followed over the total two-year length of the study. The detailed report indicates that these values were compared from the beginning to the end of the study for each subject. There are specific statistical methods needed to perform such a paired comparison, but no information is available to assess whether or not the methods used were appropriate, so it isn’t possible to say if the statistical tests reported are meaningful.

According to the report, declined or remained unchanged in 17/19 cats. (Of course, this includes the two that probably did not have kidney disease and the three that might or might not have but whose urine specific gravity was not measured at baseline.) Excuses are made for the cats whose creatinine values worsened (one was supposedly not compliant with treatment and the other was receiving medication for thyroid disease which can affect the kidneys). The fact that such possible confounders are not reported for any cats except those whose numbers didn’t change the way the author wanted them do suggests a significant risk of bias in these data. The same pattern is reported for the other variables measured, in which most improve or don’t change and those that get worse are explained away with information not provided for other subjects.

The implication here, of course, is that the failure of these variables to get worse for most cats means the RenAvast™ was working. While this is not a fair conclusion based on the limitations of this single report, the author of the report has no hesitation in making this claim:

These encouraging results prove that AB070597 can halt the advance of chronic renal failure in felines when given as an oral supplement. Supplementation with AB070597 halted increases in blood serum creatinine, blood serum urea nitrogen and blood serum phosphorus concentrations; while at the same time halted decreases in hematocrit and urine specific gravity.

Since cats with renal disease can remain stable for long periods, the fact that there is no control group is a huge problem. It is impossible to say whether or not the product did anything at all without a control group for comparison. In an unusual step, the company has provided some additional information in the form of responses to possible objections to their “study.” It is rare to have the opportunity to see such explicit arguments against what is generally considered appropriate scientific methodology, so I think it worthwhile to examine some of these arguments.

The company FAQ about the study begins by defending the very small sample size.

Many scientific studies are done with fewer subjects and over shorter time periods. In fact, there are thousands of human studies in peer reviewed journals with less than 19 patients. Nineteen patients in a study is acceptable; not to mention the fact that there are numerous over-the-counter medications used to treat humans and animals that are not based on any studies, peer reviewed or otherwise, with only subjective and anecdotal evidence as proof of efficacy.

This seems to me a fallacious argument. The fact that other studies have been done and published with no more subjects than this one isn’t itself a justification for the small sample size. Such studies may or may not have had appropriate samples sizes for the problem and population they studied, but that doesn’t tell us if this number is adequate for this population and problem. Just because others may have also used small sample sizes doesn’t mean doing so is appropriate or that the results are any less unreliable in this case. And there are specific statistical methods for evaluating whether or not a sample is large enough to answer a given question, none of which the company apparently employed in this case.

The argument that many remedies are marketed on the basis of anecdote alone is also not a justification for performing a study that isn’t capable of providing reliable information. Meaningless research is hardly a big improvement over no research at all!

The FAQ then states that biochemistry samples in the study were evaluated at a variety of laboratories. This is presented as a strength, but it may actually be a weakness. Using a variety of laboratories, each with different methods and quality control, introduces a source of variation in the data which can easily alter the findings.

Next, the FAQ attempts to answer perhaps the biggest objection to the so-called study, the absence of any control group. The response rests on two principles. First, it is claimed that a control group was unnecessary because any group not treated would undoubtedly have gotten worse, so any failure to get worse must automatically be due to the treatment:

In this particular case, a separate control group was uncalled for and would not have yielded useful information. The outcome of untreated chronic renal failure is already known: biochemical and hematological blood serum values deteriorate over time.

The problem with this argument is that it is simply false. While the general trend of chronic kidney disease is to worsen over time, the specific changes and the rate at which they happen in any individual are highly variable and unpredictable. Studies routinely show ranges in survival from days to years. Many factors can influence whether bloodwork values worsen and how fast, and none of those factors were accounted for in this study.

And there are many important variables other than bloodwork values, including body condition, appetite, and other clinical symptoms, which are only mentioned in passing but not specifically evaluated in this report.

We don’t even know from the information available whether these cats were properly diagnosed with kidney disease, what stage of disease, or any other relevant prognostic factors. Some of them, at least, clearly were not. And even if these cats all truly had some degree of chronic kidney disease, the progression of the disease over whatever unreported period of time each was followed cannot simply be assumed. Without a control group, no change or failure to change can be ascribed to the treatment in this study.

The second argument presented against a control group is that having such a group would be unethical since untreated cats would certainly die of their disease.

The use of a separate control group often raises questions of unethical behavior regarding withholding treatment from or giving placebos to the control group.

The FAQ then quotes a number of statements from the Stanford Encyclopedia of Philosophy concerning the ethics of placebo controls in clinical trials. It goes on to give an impassioned statement against the use of such controls:

The researcher does not question the superiority of randomized double-blinded studies over other forms. It is a well recognized fact, though, that their use in some situations is completely unethical. The researcher considered it completely unethical to create two groups of cats, both with CRF, and treat one group with RenAvast™ while giving the other group a placebo to merely satisfy statistical correctness. He already knew the outcome of the placebo group…. We fully support the researcher’s decision. We too, find it cruel and unethical to deny cats with CRF treatment with a product that could help them simply to create a statistic.

There are several problems with this argument. The first is that it is inconsistent with the little we know about how this trial was conducted. There is no evidence the cats placed on RenAvast™ were given standard care. Dietary therapy, for example, is well-demonstrated to improve outcomes for cats with kidney disease, yet these cats were not on dietary therapy. Other common therapies are less solidly evidence-based, but there is certainly a basis in plausibility and consensus for the use of fluid and for a number of other therapies depending on the details of the individual cases. The little information we have suggests these treatments were not provided to subjects. This study apparently substituted a completely untested supplement for standard care, which would certainly not be ethical. And if the product is not effective (and there is yet little reason to think it is), this amounted to simply not treating these cats at all, which is exactly what the author of this FAQ decries.

It is recognized practice in clinical research to test new therapies by comparing a group getting standard care plus the new therapy to patients who get only standard care. It would not have been difficult to run this study in this way, ensuring that both groups received accepted diagnosis and treatment and the only difference between them was the addition of RenAvast™ for the test group. This would have potentially provided actual information about the efficacy of this product, which the results reported here do not.

The ethical argument in the FAQ also fails because, as discussed above, the outcome was not actually known in advance as the company suggests. If we could safely assume that an experimental treatment worked before testing it, we wouldn’t need to run clinical trials at all! The reason that placebo controlled trials are ethical is because they are necessary to develop effective treatments. Without them, we simply guess and, as history and the cumulative results of thousands of such trials show, patients suffer from our ignorance. It is certainly not ethical to deny a known effective treatment to patients in a trial. But since RenAvast™ is not a known effective therapy, it is ethically questionable to give it in a clinical trial without having a control group, especially if standard care is not provided as well.

We don’t conduct trials “to create a statistic” or for “statistical correctness” but to generate the real and reliable knowledge that can only come from controlled scientific research. To conduct a trial that doesn’t produce such knowledge but merely facilitates marketing an unproven medical product is where the real ethical failing lies. This is a classic example of circular reasoning, assuming a therapy works before testing it and then claiming it would be unethical to deny this therapy to patients because it works. This is how one does faux science for marketing purposes, not real science designed to generate real growth in our knowledge and therapeutic tools.

 

Bottom Line

The ingredients in RenAvast™ are deliberately not disclosed by the company beyond the fact that they are amino acids and some sort of peptide. Therefore, it is impossible to evaluate the plausibility of the proposed mechanisms of action or any preclinical research on these ingredients.

The only data presented for safety and efficacy is a poor quality, small trial with clear and significant risk of bias that is essentially useless as evidence. There are, of course, plenty of testimonials and anecdotes suggesting the product works, but that is true for every therapy ever invented, so either no idea in medicine ever fails, or anecdotes are very reliable.

There is no way to determine at this point if the product is safe or effective. However, the way that it has been marketed shows a clear disregard for both the regulations intended to prevent inappropriate and unproven claims for dietary supplements and the basic principles of medical research. The combination of secrecy and misuse of sloppy science suggests a great deal of skepticism is in order when dealing with this company and its products.

 

What Else Do We Know?

In the absence of any real scientific evidence to evaluate the safety and efficacy of RenAvast™, it is impossible to draw any solid conclusion about the product. All we can say is that it is unproven, and even the basic plausibility of the proposed mechanisms is unclear.

While it won’t help us to evaluate the safety and efficacy of RenAvast™, there is some additional information worth considering using this product. As I have already discussed, there are a number of warning signs of snake oil, including claims of perfect safety, dramatic benefits not supported by real scientific evidence, misuse of the appearance of science to market a product, and others. I will not be surprised if we soon see another such sign in the form of a hostile response to this critique, though that is just a guess on my part.

The credentials of the folks making claims for this product are not directly relevant to the truth of those claims, but in the absence of any more specific evidence, they may be of some tangential interest. The detailed report on the cat study is attributed to “James Archer, Photo Research.” There are references elsewhere to a “Dr. James/Jim Archer” associated with Bio Health Solutions, the company marketing RenAvast™, and he has provided a radio interview on a program devoted to “integrative veterinary medicine” discussing RenAvast™.

According to this interview, Dr. Archer apparently invented prior to working with Bio Health Solutions. It is not clear what specific academic or research background Dr. Archer has. He appears to have worked largely for the Department of Defense, and though he is not a veterinarian, he indicates he has been a scientific consultant at a veterinary hospital in Southern California.

In his interview, he repeats many of the assertions for the effects of the ingredients in RenAvast™ without any additional details. He describes extensive research leading up to the development of this product, though apparently none of this has been published. He reports the results of the unpublished study and makes strong claims for the benefits of the product without addressing any of the limitations or problems discussed above. He recommends RenAvast™  be given permanently to all cats over 8 years of age! He does mention that a few of the cats had concurrent diseases or treatments during the study, and he confirms that the avoidance of diets for treatment of kidney disease was deliberate. He also reccommend using the product in dogs as well and mentions that there is research ongoing in this species.

The company web site only lists one other product, another nutritional supplement billed as an analgesic and anti-inflammatory for musculoskeletal diseases in animals. The marketing director, Mark Garrison, describes aggressive marketing of the product around the world. The company claims repeatedly on its web site to have a strong commitment to science, but this certainly is not consistent with the approach so far evinced in promoting RenAvast™.

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45 Responses to RenAvast™ for Kidney Disease: Sloppy Science and Snake Oil Marketing

  1. v.t. says:

    Ugghh, I was wondering why they didn’t use a control group who were receiving standard care (i.e., fluids, specific diet, which IS for the most part, standard care for most CRF cats)!!

    Sloppy research, sloppy study, sloppy marketing and sloppy product!

  2. Pingback: Tumexal: Wonder Drug of Snake Oil? | The SkeptVet Blog

  3. Mariah says:

    Thank you for looking into this. It’s too bad that people believe advertising and are buying this product without investigating it, and it’s too bad Amazon is selling it. Something interesting that I noticed on Amazon… in the reviews, someone named Mark Garrison (this is the owner’s name who is also the inventor and “marketing director” ) claimed how it helped his cats in response to a negative comment. I think it is quite telling that the owner is commenting on internet forums AS IF HE IS A LEGIT CUSTOMER!! I also found a Nancy (I think it was Nancy) Garrison posting on animal forums praising Renavast and claiming her cats were part of the initial study!! I always thought their initial Facebook comments and blitz praising the product in animal forums were faked so that naive people would buy it and get the placebo effect. The crime of this all is they may actually be harming the animal by ignoring standard treatments.

  4. MEOWEE says:

    Here are the ingredients in Renavast for cats as listed at vet rx direct- they’re also listed on the bottle. I was informed of this by the customer care at renvast. Amazon often doesn’t list ingredients for some reason. I have tried this for my crf kitty and unlike all the other supplements, this one didnt’ make him vomit and I hope it will help him. I also have him on pepcid, enlapril and a raw diet. He doesn’t need further treatment.

    Amino Acid and Peptide Proprietary Blend:

    L-Aspartic acid
    L-carnosine
    L-Glutamic acid
    L-glutamine
    Glycine
    L-Arginine
    L-Histidine

    Other RenAvast ingredients:

    maltodextrin
    gelatin from capsules
    magnesium stearate
    stearic acid

  5. Danny K. says:

    I have a 19 year old tabby who is suffering from CRF, which I really consider old age. He is off the charts when it comes to longevity. The vet just gave me some RenAvast.

    My vet used to work with the Humane Society and he has been my cat’s vet for 19 years. I’m going to trust him on this, but I’ll update everyone in about a week or two to tell you if there is any difference.

  6. Art says:

    Danny, Studies show veterinarians report a treatment helps 50% of the time when only a placebo is given. That’s why we need more than testimonials to determine treatment. Show this blog to your veterinarian. He may not change he mind but it may stimulate a conversation or even a post by him on this blog.

  7. Gocat says:

    Actually, the ingredients are listed on the bottle if you bothered to research it. Animal supplements rarely have any clinical studies and never have control groups. The reasons are obvious. To do a proper pharmaceutical level clinical study the makers of any supplement would have to put hundreds of cats into a control group and then monitor them for years afterwards in controlled environment. It’s not like a human study where you give the control group a set of guidelines, send them home and check back in 5 years. It’s silly to criticize the Renavast study in that context as it is more than most do. We do have to rely anecdotal evidence when it comes to a lot of animal treatments. That is why passing along good information and not fear mongering is a better policy.

  8. Gocat says:

    BTW, while I am no apologist for Renavast’s earlier aggressive marketing, I can add that my 8 year old cat was diagnosed with CKD in 2012. She had lost 2 pounds off her 9 pound frame and her kidney values were progressively deteriorating. I made a diet change to high quality wet food, filtered water and Renavast. Today she is back to full weight, her numbers improved to high normal or just above normal and have been stable for 18 months. I do not want to claim that this is solely due to Renavast because there were other interventions as well, but I would never take Renavast out of her regimen and my Vet is now offering it to her other CKD clients.

  9. skeptvet says:

    supplements rarely have any clinical studies and never have control groups. The reasons are obvious. To do a proper pharmaceutical level clinical study the makers of any supplement would have to put hundreds of cats into a control group and then monitor them for years afterwards in controlled environment. It’s not like a human study where you give the control group a set of guidelines, send them home and check back in 5 years.

    It’s clear that you know very little about how FDA licensing trials are conducted, how we use science to validate our therapies, and the costs of not conducting such evaluations. It’s true supplements in both veterinary and human medicine are rarely properly tested. This is not because such testing is not possible, affordable, or necessary but only because supplement companies have the political influence to prevent appropriate regulation, and they are not willing to do the right thing without being compelled to do so. The fact that so many people like you have been misled into believing such testing can’t or needn’t be done only makes it easier for these companies to avoid doing it.

    There is no “fear mongering” here. I have simply provided an assessment of the evidence and the reliability of the claims made by the manufacturer based on that evidence. If you believe that relying on anecdotes instead of science doesn’t hurt anyone, you don’t know much about the history of medicine.

  10. Irene de Villiers says:

    Dear Gocat and others.

    A lits of active ingredient items is not a list of ingredients and does not show whether those items come from an ingredient that is toxic to cats and may cause liver or other damage for example.
    Nineteen cats for a short while to test a CHRONIC disease is worse than a sad joke.

    However, magnesium stearate as an excipient DOES cause thymus damage and that means susceptibility to chronic disease, including FIP. (This common toxin is used to make drugs go through machinery more easily, but which can be done with less toxic options that cost a bit more – tells you where the ethics really is here).

    In my book – no ingredients list – means no use of the product.

    It’s not like there are no better options.
    Kidneys are easily repaired by feeding high ANIMAL protein and ZERO plant protein or plant oils, no fruit or vegetables, and a supplement of fish oil and Vit E.

    And THOSE ARE INGREDIENTS YOU CAN KNOW ABOUT AND TRUST.

    Namaste,
    Irene
    (Owner of Catwell yahoo group)

  11. Mark says:

    My vet have me some of this for my 21 year old cat who has ckd but excellent health than that ( and some teeth, sight, and a little stiff in her legs).

    She wasn’t eating so it was hard to give her, but now she us eating and I plan on giving it a try. I have had numerous cats, most ended dying of kidney failure. So, I know her symptoms now and I knew exactly what is to come.

    If this improves her, I will believe that it has merit. If it doesn’t, then it probably doesn’t help.

    I will let you know.

  12. v.t. says:

    Mark,

    And what if it harms her?

    That’s the crux of this issue. No one knows the “proprietary” ingredients, amounts, formulations, whether or not there are harmful substances added, etc. Above all, the manufacturer has done nothing to convince anyone whether this product is safe or effective. Key word, nothing. Sloppy study that would never make a peer-reviewed publication, refusal to divulge formulation of ingredients and/or additional ingredients, and marketing gimmicks galore (dubious claims), without one shred of evidence it does what they say. Your kitty deserves better than that.

  13. Mark says:

    Harms her? You mean like the inevitable pain and death of kidney failure? It is marketed as a nutritional supplement. I don’t think amino acids are going to harm her more than what I know for a fact is going to come…and come soon. My kitty deserves a chance. Plus, I have an excellent vet so if he is convinced, I will give it a try. She is 21 and her life will be ending soon. I feel very comfortable giving it a try bc I know the alternative. We take chemo (literal poison to our bodies) to extend human lives all the time. Chemo is a gamble and it impacts everyone differently. My mother in law had extended her life. My friend was killed by the chemo. These are choices we all make everyday. I am trying it.

  14. Mark says:

    Irene, kidneys are not easily repaired through diet. I know! Been there done that.

  15. Mark says:

    Also, I will post my findings, good or bad, right or wrong on my part. I have a full blood panel of organ function before the supplement so it should be easy to discern.

  16. DMG says:

    My vet suggested this supplement when my 15 year old cat had to go on Meticam for arthritis in his back. At the time his BUN numbers were just slightly high but Meticam is known for causing kidney problems. She said she had heard of this product and put 2 of her own old cats on it before she would suggest it to her clients. He has now been on it for about 6 months (along with weekly Meticam doses)and his kidney function has improved. I’m personally sold on it. Most supplements don’t have big clinical trials as there isn’t enough money to be made on them unlike prescription drugs. Then most people wouldn’t be able to afford them for their pets.

  17. Holly says:

    My dog was diagnosed with CRF in March. I have been trying many things to help her to no avail. A week ago she took a turn for the worse and I was preparing for the worst. My Vet very honesty said I don’t know if this will work some people say it is hocus pocus but she has seen it help cats. I said I will try anything. Well it has been amazing RevAvast along with SC fluids and she is eating, not vomiting and putting on weight. She is never going to be 100% but her quality of life has improved dramatically. If they are dying anyway why not try it especially since it works. Someone should invest in a real Study maybe the person who wrote the review should out your money where your mouth is and pay to do a study.

    IMO…

  18. skeptvet says:

    So the company that sells the product and makes money from it is free to make claims based only on anecdotes, but if I criticize this then I ought to pay for studies to see if the product works? That is a pretty bizarre way to look at testing medical treatments.

    I’m glad your cat is doing well, but it doesn’t prove anything about this product any more than all the similar anecdotes for every other therapy ever tried proved they worked. If we relied only on anecdote, we’d still be practicing bloodletting and ritual sacrifice to treat illness. And if we let anyone market whatever they want with whatever claims they want and expect only skeptics to pay to generate real scientific evidence, then we are returning to the days of snake oils that killed millions of people.

  19. Mark says:

    mini follow up. My cat is responding to this supplement. She was needing fluids every other day and the food stimulant bc she wouldn’t eat. Now she has more energy and her appetite is up. She doesn’t seem to need the fluids as fast. I went 4 days and she still was eating and having energy when I took her in for fluids last. It is definitely helping the kidneys but I want to wait a little longer before getting her full blood panel again ( fit comparison).

    I actually agree that they are super secretive about the formula and study and this is cause for suspicion, but it didn’t change the fact that my cat was near dying and now is walkng around, jumping, hitting the cat box, eating, energetic, etc and all in her own. I will let you know in few weeks of her status. Hope this is a positive trend for this 21y/o girl.

  20. Mark says:

    “The study is currently being peer reviewed and we expect publication in a respected journal by the end of the year.” -this was from an email I got asking them for the study info. This is odd that they won’t share it. Even though it seems to be helping my cat, I have noted my calendar to contact them again in 6 months for the info.

  21. Andie says:

    ” Studies show veterinarians report a treatment helps 50% of the time when only a placebo is given.”

    Since a placebo effect is mainly psychological, how does an animal qualify for a placebo effect?

  22. skeptvet says:

    The point of this is that studies how people, vets and owners, report a benefit when a fake treatment is given. A huge chunk of the placebo effect in animals is due to the fact that animals can’t report their own symptoms. People decide whether an animal is responding to a therapy, and we are wrong 30-50% of the time when the therapy doesn’t actually work and we think it does. That’s just a reminder of why anecdotes like “I gave Treatment X to my dog and he felt better so X works” are not reliable.

    There are some other ways in which placebo effects operate besides beliefs and expectations, and these apply to dogs and cats as well, but most of the effect is on the people caring for the pets which think something is happening when it isn’t.

  23. Mark says:

    You say fake, but in doing so you show your bias. It isn’t fake just because it hasn’t been studied to the level of your liking. It may work, but had not yet been studied to the level of your liking. It would be like saying that a tomato had no nutritional value before they studied it.

  24. Donna says:

    I can attest to the study as well as the effectiveness of Renavast. It saved both of my kitties lives. Two of my cats were part of the study for Renavast. One kitty named Ruby, died of a heart attack 3 years ago at age 18 and was on Renavast for 2 years before she passed.
    And my other cat Charlie is 18 and is currently doing very well andhe has been on it for 5 years now.
    Both cats were given blood work every 6 months and all symptoms, blood work etc. were were followed very closely by Mr. Archer. Both cats were diagnosed with kidney disease at the high end of normal.
    I had a cat die of kidney disease in 1993 and vowed to never put a kitty through such
    a painful death again, so I know how devastating it can be to watch your companion rapidly die after a few short months.
    Little did I know at the time, but do now that when a Vet finally tells you that your cat has kidney disease and or renal failure, your cat probably only has about 40% of its kidney function left. And this is if they are at the high end of normal. Most people don’t realize that when this is said to you, your cat is basically only going to live a few more months as kidney disease progresses rapidly. Sure you can do the fluids, the expensive unhealthy food from Hills or Royal Canin, or the expensive Azodyl treatment at 100 dollars a bottle form your vet all simultaneously to keep your cat going from day to day. Or you can do what I did. I changed both my cats diet to Wellness, high protein grain free diet and started giving them Renavast. No fluids, no expensive foods etc.
    I can only share my experience and say that my happy, healthy kitty Charlie, is all
    the proof I need. Renavast did not cure him, but it stopped the disease in its tracks
    and he has not gotten worse.

  25. skeptvet says:

    Not that you’re going to care, but for the record anecdotes like this prove nothing (see below), the rate of progression of kidney disease is variable, unpredictable, and often not nearly as rapid as you suggest would have happened without the Renavast, and the renal diets you call “unhealthy” are proven to improve quality and length of life, which Renavast is not. If this sort of uncontrolled personal observation were really reliable, we wouldn’t need science. But if we still relied on anecdotes instead of science, we’d still be relying on bloodletting and prayer and half of us wouldn’t live to adulthood. No thanks.

    Testimonials Lie

    Medical Miracles-Should We Believe?

  26. Donna says:

    This is not an uncontrolled personal observation. Charlie has NOT been on any other supplement other than Renavast since he was diagnosed with kidney disease 5 years ago and I have the Vet records to prove it.
    He is 18 years old and was diagnosed with kidney disease at the high end of normal in 2009. He should have died years ago.
    His latest blood work as of about 3 weeks ago show levels of BUN (blood urea nitrogen), creatinine, and phosphorus to all be about the same as they were 6 months before and before that. His levels have stopped getting worse and he is ALIVE and healthy. The proof is in the pudding dear doctor. And as far prescribed diets to treat renal failure made by Hills and Royal Canin, please read any and all literature on the subject by Dr. Lisa Pierson and stick it in your pipe and smoke it.

    Excerpt form Dr. Lisa Pierson DVM in reference to prescription diets for cats:

    “Many of these very expensive products contain corn, wheat, and soy which have no logical place in your cat’s diet. These diets are often very high in carbohydrates and, of course, all of the dry versions are water-depleted. Many of them also contain by-products as the main – and often only – source of protein.

    It is important to note that most of these diets do not have robust clinical feeding studies supporting their safety for long-term feeding or even for use in treating the various diseases they target.

    On the contrary, we have plenty of evidence to show that feeding water-depleted, high carbohydrate, plant-based diets to carnivores does not honor their carnivorous make-up but, instead, promotes disease in this species.

    It is also critical to understand that there is no independent agency overseeing these diets’ medical claims. None. Zero. Including the FDA.

    The fox is definitely guarding the henhouse and the FDA shows no interest in remedying the situation.

    The FDA has ‘punted’ the responsibility of scrutinizing these diets for efficacy, safety, and suitability to the veterinarian but most veterinarians are very poorly educated in the area of nutrition. This field of study is not emphasized in veterinary schools and the minimal course work that is required, is often taught by people who have strong ties to the pet food industry.

    These are also usually the same people who are advising general practitioners on all matters of nutrition. After recognizing this situation, you will see an obvious and very significant conflict of interest. In the end, the members of my profession allow Hill’s, Purina, Iams, and Royal Canin to dictate what ends up in our patients’ food bowls”.

  27. v.t. says:

    Donna, just so you know, “high end of normal” does not necessarily mean renal “failure”. Many cats can live with chronic renal disease for several years with proper care. Thankfully, your Charlie is a great example and may he have more happy years ahead!

    Quoting Lisa Pierson doesn’t help your argument. Some of her comments make sense, some of her other comments are complete nonsense.

    Lastly, most of the prescription diets are not usually intended to be fed long-term, as both you and Lisa Pierson are fully aware. That said, no other pet food manufacturer has ever formulated an equal to or better than formulation for a specific health issue, and one that actually has addressed such issue with results. Well, save for Fancy Feast, the diabetic cats’ and the finicky cats’ dream 🙂

  28. Donna says:

    I never described Charlie’s condition as renal failure, I described it as renal disease. We both know that when a kitty presents with kidney levels at the high end of normal, they only have 30% kidney function left. Without treatment of any kind, they may die within a year.
    The “proper care” that you refer to is very vague.
    Charlie has been given Renavst ONLY for the last 5 years and NO other supplements or prescription diets. His diet has been Wellness wet food Beef & Chicken. One half can twice daily. To anyone reading this besides, the dear doctor here, try it, it works.
    The proof is in the pudding.

  29. skeptvet says:

    “Renal failure” is just a term for chronic kidney disease, not a suggestion that clinical symptoms are imminent, so we are talking about the same thing. Ideally, Charlie’s disease should be staged according to the IRIS staging system, but the point is that “may die within a year” is not different from saying “may live for several years.” The precise prognosis is unpredictable, and so whether he would have lived just as long without Renavast is something no one can know.

    As for “proper care,” again I refer you to the IRIS guidelines for treatment, which are not at all vague.

    The “proof” is not in an anecdote like this but in proper controlled scientific research. If anecdotes are sufficient proof alone, than bloodletting, Lourdes water, and a thousand other treatments work just as well as Renavast, and it becomes difficult to explain why we still have any disease at all since every therapy out there can produce anecdotes showing miraculous results.

  30. Cam says:

    I heard about RenAvast from a chat room. Our cat is 17 and eight years ago it was discovered through Xrays for something else that she had half of one kidney still functional and it didn’t look too good. She’s always vomited a lot, but two weeks ago she was throwing up everything, even water. She also has an inoperable abdominal tumor, so we were thinking the tumor had gotten in the way and we’d have to put her down right after Thanksgiving or maybe before. We decided to take a chance in case it was kidney issues, $23 is cheaper than a vet visit, and it has been amazing! She is hungry (very) and super-frisky, her poops are normal, she is drinking less and peeing less too. (Normally, not huge amounts like before.) So for what it’s worth, RenAvast is working. It’s better than a dead cat, it’s bought her some time, and she feels good. We know she’ll die from either the tumor or the kidney situation, and she’s old so there’s not much we can do but keep her comfortable. We are not vets, we only have the one elderly cat, but we are delighted with the results.

  31. skeptvet says:

    it was discovered through Xrays for something else that she had half of one kidney still functional and it didn’t look too good

    This cannot be determined by x-rays, so clearly something is wrong with either the diagnosis or your understanding of what was found. One of the biggest weaknesses of testimonials like this is that there is no way to be sure the problem someone thinks they are treating is actually the real problem. In this case, your cat may have kidney disease, though the explanation you give for how that was determined doesn’t make sense, but even if she does this may have nothing to do with the symptoms, and the improvement may have nothing to do with the Renavast. Likewise, if she has a tumor, this is more likely to be the cause of the symptoms, and no one claims Renavast treats abdominal tumors, so there’s no reason to think the Renavast is responsible for the change.

    As for being cheaper than seeing a doctor, is this really the best way to choose a medical treatment? If you had an abdominal tumor and kidney failure, would you go to the drug store and by some untested over-the-counter remedy or see a doctor?

  32. Cam says:

    Our cat was crushed from the middle back by the drug dealers who lived next door to us. We had her at the emergency vet and then to two others. They all took X-rays of her spine and pelvis in various views, and the kidneys did indeed show up. One is tiny and shriveled and the other is only partly there. Her kidney values were slightly abnormal, this was eight years ago and we were warned to watch for excessive thirst and urination, as well as vomiting, because all of the vets who treated her were of the same opinion that she would eventually show the classic symptoms of CRF. (And we are aware of them too as we have had a couple of other elderly cats who eventually died from kidney problems.) These symptoms have developed, she is 17 and we are not going to put her through too much in the way of testing and treatment due to her age, frailty (even though the eight pelvic fractures, broken leg and hip too have healed), and general debility. We just want her comfortable. I have no idea why RenAvast worked but it did. We went from four to six barfs a day to one a week. It was like flipping a switch. So snake oil or not, it’s working. I don’t understand it either.

  33. Cam says:

    I fully agree about the placebo effect, but…the cat feels better. We don’t know for how long and there is no other treatment other than SubQ fluids for her at this point in her disease. And, I repeat, it was cheaper than a vet visit and euthanasia. Her tumor is small and inoperable due to her general state of health. Either that will get her or the kidney stuff will, likely sooner rather than later, so we’re all about quality of life. Hers, obviously–and a side benefit is ours, since we aren’t scrubbing the floors, rugs, and furniture quite so often.

  34. SirWired says:

    I know this is an old article, but thought I would throw in my comments…

    Our cat Jessie passed away in the fall seven YEARS after being diagnosed with CRF (bloodwork, and confirmed by an ultrasound). She didn’t receive any mysterious supplement, just Hill’s k/d and sub-Q fluids. (eventually 200ml every other day.) That was enough to keep her bloodwork steady and just hovering around the high end of normal. If she had received this supplement, we can fully expect that that would be counted as “evidence” of the supplement’s success if I was the credulous type. (As a side-note, why on earth would one ever suggest a diet high in protein (animal or otherwise) to a kidney cat? The mind boggles; they don’t consider high nitrogen levels in the blood a bad thing for no reason…)

    Over that seven years, her kidney issues consisted of a few kidney, ureter, and bladder stones (including a stone in one ureter so large a human could never pass it, yet it mysteriously disappeared!) and a couple bladder infections. (One of those put her in the hospital for five days, but she pulled through.) In the end, it wasn’t even her kidneys that killed her, it was lymphoma that got her colon (it was spotted on ultrasound when we had that infection treated, and we elected not to biopsy or treat because we did not believe she would survive chemo with her compromised kidneys.)

    We are grateful for all the wonderful care she received over the years, and are also grateful that our vet did not push all sorts of dubious quackery on us during all that time.

  35. Raegen salais says:

    If it’s only amino acids and wouldn’t harm a cat even if it didn’t help why wouldn’t it be worth trying ? Since no harm done if it didn’t help ?

  36. skeptvet says:

    The problem with that approach is that not having evidence means not just that we don’t know if it’s effective, it also means we don’t know if it’s safe. Only amino acids are listed on the bottle, but there are no regulations governing content, so who knows what else is in it? A recent investigation of GNC, Target, and Walmart found that many of their purported herbal products didn’t actually contain what was on the label, because unlike pharmaceuticals nobody is watching. The same lack of oversight applies to supplements for animals.

    My own guess is that the risk is low, but it’s just a guess, and given there’s no reason to think it would help it’s just one more thing to force your sick cat to take. As I mentioned earlier, anyone who does try it should at least be very careful that it doesn’t reduce their cats appetite, because cats with renal disease can be very picky about food and easily put off their diet.

  37. Pam says:

    This supplement has been the changing factor in my dog’s health. My 13 year old Pomeranian has been in congestive heart failure since before adopted her. Seven months after adopting, her kidneys began failing, she was in so much kidney/body pain and was being blinded by Uriec ulcers.
    The ONLY changes I made was giving her RenAvast 2x/day and an eye ointment.
    Within a few weeks her pain was gone completely. She started acting and functioning like her old self. I’m only meant was administered 3-4 months and whether that is what he told the authors or whether the urea in her system was lowered by the supplement I do not know. However, I do know the ulcers are gone as well.
    A dog given likey less than six months to live has now been taking the supplement for a year and a half and is acting younger More energetic than ever before!
    Too much coincidence for me to not believe RenAvast (now called AminAvast) works and has made the difference between life and death.

  38. skeptvet says:

    I’m glad your dog is doing well, but unfortunately the lesson of the history of medicine is clear that coincidence is often just that, and that relying on such anecdotes leads to far more harm than good in the long run. Scientific evidence is not just a picky academic way of confirming what we already know, but a way of getting at the real truth under all the misconceptions we are easily led into by such observations. I understand why it is hard to accept, but here are some very clear and detailed explanations for why we can’t trust such stories no matter how obvious the moral of them may seem to be:

    Why We’re Often Wrong

    The Role of Anecdotes in Science-Based Medicine

    Why We Need Science: “I saw it with my own eyes” Is Not Enough

    Don’t Believe your Eyes (or Your Brain)

    Medical Miracles: Should We Believe?

    Testimonials Lie

    Alternative medicine and placebo effects in pets

    Medical Practices Once Widely Accepted that Proved Ineffective or Harmful when Studied Scientifically

  39. We are a rescue. I have used this product extensively on cats. It works well if your cat is not too far into kidney failure. As long as you have a senior blood panel run and your cat is just starting to show increased BUN and Creatnine levels, it works like a charm. It will also work to eliminate the vomiting in cats well into kidney failure and make their final time more comfortable. I have also used it on our senior dogs, so far so good.
    I am very satisfied with the product and am about to reorder, and I recommend it to everyone.

  40. TONI says:

    Renavast definitely works! You can call it coincidence but my 18 yr old cat was diagnosed with kidney issues – increased BUN levels several years ago. She had lost weight and was wobbly. After less than a month on Renavast she made a turnaround and is still going strong. You can say whatever you want to about the scientific studies but I did nothing other than put her on Renavast. One and 1/2 years after her first diagnosis she had maintained her weight. The vet asked me what I was doing. No other changes in her living circumstances or diet except Renavast . The ingredients are listed so that is a mistake on your part. I understand your perspective but for me the bottom line is that she is alive and well.

  41. Deborah T says:

    My 5 year-old cat Dane has been on RenAvast for 3 or so years. He was diagnosed with chronic kidney disease within a year after we got him at 7 months. Our vet says she was involved in a clinical trial of RenAvast and recommended it. I am skeptical and still am. Nevertheless, we are using it as we have believed the claim that it is not harmful to cats. Although this is purely anecdotal, Dane’s creatinine has remained a steady 2.6 for 3 years. He is fed grain-free wet food (canned) mixed with a little water and the RenAvast. We know that there is nothing that can IMPROVE his kidney function but we hope it will remain steady without deteriorating for years to come. We believed RenAvast is either helping or it isn’t helping, but either way, wasn’t harming him. Last week, he developed diarrhea which our other cat Sophie had, and we thought it was a “bug.” Sophie got better in a couple of days but Dane became lethargic and wouldn’t eat. We thought he was dehydrated so we took him to ACCESS/City of Angels (I mention the name because they are very reputable) expecting he would simply need fluid resuscitation. Ultrasound revealed significant thickening of the small bowel and prominent mesenteric lymph nodes. The diagnosis is one of 2 things: irritable bowel disease or intestinal lymphoma. It’s possible that the two cats had the same “bug” and the findings on ultrasound were incidental to the diarrhea although obviously far more serious. (These two diseases do not always produce symptoms, at least in the beginning.) Now I’m wondering if the RenAvast didn’t cause the thickening of the intestine. This probably sounds crazy but everyone on this blog knows what happens to our brains when our darling cats become ill. Skeptvet, any thoughts about any harm that can result from the known ingredients in RenAvast? Anyway, I thought it was interesting that RenAvast recently changed its name to AminoVast. I wonder if it has anything to do with the FDA inquiry.

  42. Debbie McNelly says:

    All I can say is that my cat was diagnosed with early kidney disease in 2008.She is now 17 years old and going strong…. Her numbers stabilized after her first year taking it.Whatever it is or does…IT WORKS FOR MY BABY GIRL.

  43. skeptvet says:

    Or she did well despite, rather than because, of this treatment. I can point you to many patients of mine who have done just as well without this treatment. The problem is in assuming that the outcome s due to the particular action you choose to identify as the cause rather than to any of the hundreds of other important sources of variation in individual patient outcomes. Here is another way of looking at that problem:

    Why Anecdotes Can’t Be Trusted

  44. Gwynethnotpaltrow says:

    Thanks for your clear explanations, skeptvet. My vet recommended this product (now called AminAvast*, after being banned by the FDA), but I wondered why I had to buy it on the internet. I tried searching Web of Science and PubMed for any peer-reviewed publications on the critical ingredient “AB070597” and came up with nada.

    Not to question those whose animals have improved, but there doesn’t seem to be any objective evidence that it’s the RenAvast (or AminAvast) that’s doing the fixing. I’ve not been that happy with this vet, and this may be the last straw…

    *https://www.avma.org/News/JAVMANews/Pages/151015n.aspx

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