N-Acetylcarnosine Eyedrops for Cataracts in Dogs and Cats (Can-C, Bright Eyes NAC, etc)

A client recently asked for my opinion about the value of some over-the-counter eye drops purported to treat cataracts in dogs and cats. Not having read much about this product, I did a little research.

What Is It?
There are a number of eye drops marketed for prevention or treatment of cataracts in humans and pets. Most commonly, they contain a chemical called n-acetylcarnosine, which is made up of a couple amino acids and an acetyl group. In vitro research suggests this chemical has anti-oxidant effects, so it has been hypothesized to prevent or reduce the gradual opacification of the lens of the eye through this mechansism. As I have pointed out before, the role of oxidative damage in disease, and the value of anti-oxidant therapies, is a developing area of research. Many of the exuberant and enthusiastic hopes in this area have proven false, so while it is an area deserving further investigation, claiming something is an anti-oxidant is not automatic validation of its safety or benefits (e.g. 1, 2, 3).

Does It Work?
There have been a number of studies of n-acetylcarnosine, both in vitro studies and clinical trials in humans. Interestingly, almost all of these appear to have been published by the same researcher and his team, Dr. Mark Babizhayev. A clinical trial was published in 2001 (and it appears the same data was published again in a different journal in 2002, which if true is quite a significant science no-no). The trial was randomized and controlled in a small number of patients, and it appeared to show significant changes in a number of objective measures of cataract severity.

I am not familiar with the specific techniques used to measure the disease or response to treatment, so I will presume they are standard and appropriate measures for this kind of study. One thing that is not clear from the published report is whether the individuals making these measurements were blinded to the treatment status. This obviously has a significant bearing on the reliability of the results, especially when they stem from only one researcher, as such debacles as the Benveniste affair show.

A number of subsequent papers have been published by Dr Babizhayev and his team, mostly in vitro or lab studies investigating properties of n-acetylcarnosine, not clinical trials. Dr. Babizhayev has also become the leader of a commercial firm marketing n-acetylcarnosine for cataract treatment, and many other uses (including skin care, wound care, respiratory disease, and neurologic disease).

This commercial effort, and the spreading of claims for n-acetylcarnosine to a wide range of apparently unrelated applications, does raise some questions about the reliability of Dr. Babizhayev as the sole source of scientific validation for this compound. Overall, the status of the evidence for use of n-acetycarnosine for cataracts in humans is best summarized by the Royal College of Opthalmology:

 

The evidence for the effectiveness of N-acetyl carnosine eye drops is based on experience on a small number of cases carried out by a Russian researcher team. To date, the research has not been corroborated and the results replicated by others. The long-term effect is unknown.

Unfortunately, the evidence to date does not support the ‘promising potential’ of this drug in cataract reversal. More robust data from well conducted clinical trials on adequate sample sizes will be required to support these claims of efficacy.

Furthermore, we do not feel the evidence base for the safety is in any way sufficient

Unusually, there is actually some clinical trial evidence in veterinary species as well. An uncontrolled, unblended pilot trial has been published on an n-acetylcarnosine product (not the one Dr. Babizhayev sells) in dogs with cataracts.

David L Williams, Patricia Munday. The effect of a topical antioxidant formulation including N-acetyl carnosine on canine cataract: a preliminary study. Vet Ophthalmol. 2006 Sep-Oct;9(5):311-6. The results showed marginal improvement in all groups, though it was only significant in patients with 2 out of 5 types of cataract treated. However, subjectively owners reported improvement in 80% of the subjects.

Dr. Williams ย has apparently performed a blinded, placebo-controlled follow-up trial on this product which did not show any benefits (in fact improvements were greater in the placebo group than in the treatment group), showing once again the importance of proper controls for bias, confounding, and other sources of error in clinical trials. Unfortunately, it appears unlikely this trial will be published for reasons which are not completely clear, though one implied issue is that journals are often reluctant to accept papers that show negative results, which are less exciting for readers than positive studies. All of this is, of course, through word-of-mouth among veterinarians, so I cannot confirm it is true.ย ย 

Is It Safe?
I have not found any reports of adverse effects from ophthalmic application of N-acetylcarnosine itself, and given its chemical makeup it seems unlikely to be hazardous. As usual, products containing this agent are not regulated as licensed medicines are, and there is no way to ensure label accuracy, proper manufacturing quality standards, or the safety of other ingredients that may be included with the N-acetylcarnosine.ย 

Bottom Line
The theoretical arguments for why this drug might be useful I the treatment of canine cataracts are plausible but largely unproven. There is limited clinical trial evidence in humans suggesting a benefit, but this has not been replicated and is at high risk of bias. The limited clinical trial evidence available in dogs does not suggest a benefit. There are minimal safety concerns with products containing N-acetylcarnosine.

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172 Responses to N-Acetylcarnosine Eyedrops for Cataracts in Dogs and Cats (Can-C, Bright Eyes NAC, etc)

  1. Rita says:

    Double-blind tests for a catarect product! Ouch!, the punning!

  2. Rita says:

    The blog disappeared for a few days there………

  3. skeptvet says:

    Yes. Arrgggg! My host migrated the site to a new server and somehow set it up so that the doman registration didn’t renew automatically when it was supposed to. All better now. ๐Ÿ™‚

  4. Rita says:

    I thought perhaps you hadn’t got your chakras lined up….. ๐Ÿ™‚

  5. Jimmy's mom says:

    Thank you for your excellent summary of using OTC drops to treat cataracts in dogs. I was looking for alternatives to surgery and found many articles about the benefits of using the drops but you have effectively debunked the claims. Keep up the good work!!

  6. Averil says:

    Yes, but it might be worth trying. Eye surgery for dogs is very expensive.

  7. skeptvet says:

    Separate issues. Sure, surgery is expensive, and not everyone can afford it. That’s not really a reason to pay for something useless to put in the dog’s eye, though.

  8. Gabrielle says:

    I have an older dog with severe cataracts. I have contacted many of dog opthamologist to remove the cataracts and found that canine cataract surgery is thousands of dollars more then cataract surgery for people. I do not understand why that is the case. Is there an explanation?

  9. skeptvet says:

    Obviously, I don’t have any ifnormation about which opthalmologists charge what for this surgery, and I am not an opthalmologist so I don’t do the procedure myself or know anything about the costs.

    I will point out that people often make the mistake of thinking a particular therapy for their pet is more expensive than the same therapy for humans. This is usually a misconception arising from the fact that you have to pay your vet directly whereas insurance often covers most of the cost for a procedure on a person and you pay only a co-payment or deductible. It is also the case that medicare and other reimbursement schedules for insurance payments artifically set the cost of procedures when these organizations are paying the cost, so the charge on the bill may not reflect the actual cost. Finally, procedures in animals aren’t always the same as in humans. Eye surgery and dentistry, for example, require general anesthesia in animals, whereas they are usually done awake in humans, and this increases the cost significantly.

  10. Satn says:

    I am trying this drops, I will find out in 2 months if there’s any difference. I don’t have the money to get my dog to surgery, BUT CERTAINLY I will try other alternatives. Anything could happen, and the last thing to lose is hope when you really CARE about your pet. In case they don’t work, at least I tried and I will never regret it. I don’t encourage just accepting a negative outcome regardless. Don’t be conformist people! Experiment alternatives (as long as there’s a degree of safety, or innocuity) when it comes to care for your beloved ones. Don’t just accept and do nothing.

  11. skeptvet says:

    Sure, do something, anything, even if it doesn’t work or makes things worse. That’s how you show your really CARE. Sheesh!

  12. Bob Gordon says:

    Our vet has prescibed Diclofenac Sodium Ophthalmic solution to ease possible discomfort associated with cataracts in our 16 year old poodle. Don’t know if cataracts cause discomfort and if so is this the right eye drop medication or would a simple lubricant be more appropriate.

  13. skeptvet says:

    I’m afraid I can’t offer specific advice for your pet. That should come from a doctor whoc knows you and your dog directly and is involved in his care. If you have questions about your vet’s recommendations, a second opinion, ideally from a board-certified veterinary opthalmologist, would be a good idea.

    Good luck!

  14. v.t. says:

    Bob Gordon, cataracts can indeed cause pain, inflammation and light sensitivity, depending on degree of seriousness or corneal/retinal damage. The drops your vet has given you might help with any pain aspect, but as skeptvet advises, any questions you have about the medication should be addressed to your vet and a veterinary opthalmologist would be an expert in diagnosis and treatment options.

  15. mrsd says:

    i took my 4 yr. old dog to a canine ophthalmologist and was told that cataracts are not painful, however, cause inflammation; which in turn causes problems that can be painful. to keep the inflammation in check she gave me Diclofenac Sodium Ophthalmic solution to apply 1 drop twice a day. this solution is an anti-inflammatory like Advil. she said he’d be on these drops for the rest of his life.
    when i asked about N-acetylcarnosine the vet said there’s no proof that these drops help and because she doesn’t prescribe them she wouldn’t be able to say whether or not they would harm my dog when used with the diclofenac she gave me.
    needless to say, i’m pretty upset about the entire thing. i don’t want to put my dog through the surgery. forget the $4,000 price tag – there’s a chance of serious complications post-op that i just couldn’t bear for him.
    if anyone here has had any success with n-acetylcarnosine i hope you’ll post. i’m trying to read everything i can find about it so i can make an educated decision.

  16. v.t. says:

    mrsd, please read the article above again. So far, it suggests that studies on n-acetylcarnosine are lacking in safety and efficacy. Until more research is done (and who knows when that will happen), you should probably follow your vet’s direction and recommendations on your dog’s current therapy, including regular eye exams to monitor progress.

  17. Patricia pepper says:

    I know an excellent doctor who says that the N- acetylcarnosine drops work.

  18. skeptvet says:

    And I know several who say it doesn’t. So? Uncontrolled individual experiences or opinions aren’t a very useful or reliable way to decide if a therapy works or not. High quality scientific research is a lot better.

  19. Yoshi says:

    Hi Skeptvet, thank you very much for this helpful information and for your efforts on this research. However, I hope you will be a little more open-minded and a little more empathetic to the people who posts here that are searching for alternatives aside from the expensive surgery. We all love our pets so much but not everyone can afford to give the best of treatments that our pets deserve and we want to find second best options/alternatives for our beloved pets because this is the only option we have. Since this research on NAC is not proven safe and effective, on the other hand there is no proof of it that it is uneffective and unsafe to use right? If you think this medicine is harmful to even try. I hope you can help us understand more on the harmful effects it could cause our pets or pls kindly suggest some other alternatives that you know of that we could try aside from surgery. Thank u very much and i hope you dont take this negatively, i just wanted people to understand the pressure of pwt owners like us who loves our pets to death but just cant afford expensive treatments but will still do everything we can to help our pets in a non-harmful way.

  20. skeptvet says:

    I’m sorry if you think I am being critical of pet owners seeking alternatives, but I truly am not. The whole reason I write this blog is so pet owners will have the facts and information they need to make an informed decision when almost everything else available to them is propoganda or advertising from people selling these unproven therapies. It is not pet owners desperate for help who are to blame, but companies and individuals takinga dvantage of that desperation by selling untested or outright ineffective remedies.

    As for har, the usual assumption, which you seem to be making, is that if there is no evidence showing something works it at least can’t do any harm. But that is an error. If there is no evidence showing a treatment is effective, it can be harmful in two ways. first, the lack of evidence regarding effectiveness is ften accompanied by a lack of evdience it is safe. When we haven’t properly tested something, we don’t really know if it works OR if it is safe. I have a long list of studies showing direct harm done by therapies assumed to be safe before they were properly tested.

    The second way these things can be harmful is by delaying or subtituting for therapies that really are effective. If peopel try these things and they don’t work, they have often lost the chance to truly make the problem better.

    The best answer I can give people who are unable to afford therapies known to work is that when you try things not properly tested, you roll the dice and take your chances. The need to try something, anything is udnerstandable, but it can make things worse, and that’s the risk you have to decide whether or not to take.

  21. v.t. says:

    Yoshi,

    Understand that being open-minded does not mean dismissing evidence and the science behind medicine, in favor of unproven and potentially harmful alternative treatments.

    Yes, costs of treatment can sometimes be prohibitive. But, when considering alternatives, at least those in the CAVM sense, you will often pay far more for those alternatives because CAVM is largely based on faith and belief (not science), claims that have not been proven by scientific standards, and sometimes outright fraud to sell you something over and over again because it was never proven to work in the first place. When alternative medicine is proven to work, it ceases to become alternative and becomes medicine. At what cost are you willing to help your pets? If your pet could speak, what do you think they would choose to stop hurting, to cure disease, to alleviate pain, etc?

  22. mrsd says:

    @patricia pepper – you know an excellent vet that uses NAC drops? can you tell us who that is and where he/she is located?
    right now the only treatment i have is the anti-inflammatory rx, which incidentally, made my dog’s eye red and irritated – go figure. the other alternative (surgery) isn’t a option. i’m trying my hardest to find an actual vet that has experience with these drops. i won’t put anything into my dog’s eye that isn’t proven safe. it’s one thing to try something and find it didn’t work; it’s a total other thing to try something and find it hurt my dog – i’m not going to let that happen.
    so again, if anyone out there has any real experience with NAC drops, please post and give me contact information. thanks.

  23. Yoshi says:

    Hi Skeptvet and also to V.t., thank you for your positive explanation. I understand what you mean now and thank you again for doing this research. I am currently very confused and sad for my dog’s condition and i am eagerly hoping that there are ways to treat her cataracts non-invasively. But I agree with you that there is a larger chance that this NAC eyedrops would do harm than good. Thank you for pointing that out this made me realize how big the risk was for this alternative that I was considering to take for my dog. I have seen some people saying flaxseed oils and MSM is a natural way to treat cataracts, what is your take on this one? I really hope you could shed some light on this too.. And can I ask you one more thing? Is it really necessary for my dog to have a surgery? And how soon should she have the surgery? I think she got her cataracts from an eye trauma some couple of months ago, the doctor gave her an oral medicine and tobramycin.. I used tobra for a month or so for both eyes and it started to turn whitish.. Then had her checked by a pet opthalmologist, that’s the time she was diagnosed with cataract on one eye. The doctor gave her diclofenac sodium and VT Phak on the other a week ago.. But now the better eye turned whitish too.. And she seems to be blind now or can see just a little.. :(…..

  24. v.t. says:

    Yoshi, those are questions best answered by your veterinary opthalmologist – he’s the only one who has examined your dog, and can determine the extent of the problem or if surgery offers a better outcome.

    While surgery is not without some risks, leaving cataracts untreated could also carry some significant risks – depending on the severity. Not every dog will have these risks, but only the opthalmologist can determine what is best for your dog based on the extent of injury, or if further damage is likely without surgery. The purpose of surgery is to attempt to restore vision (even if only partial), and to decrease the risks for retinal detachment, lens luxation and glaucoma, any of which can cause further damage to an untreated eye (and all of which can cause significant and debilitating pain). Some dogs with cataracts can be managed with medication or opthalmic drops, without surgery, it depends on the individual and the extent of damage.

    If some or all of the drops you’ve been given are not producing favorable results, then you know you have to have further discussion with your veterinary opthalmologist – it could be that another medicated eye drop may be all that is needed, or it could be that surgery is indicated to prevent a more serious problem from developing. The opthalmologist is the only one who can determine that and help you make appropriate treatment decisions. I would at least suggest that your veterinary opthalmologist is board-certified.

  25. Yoshi says:

    Hi V.t.,

    Thank you very much for your extensive explanation and information. I greatly appreciate your concern. Btw, I am now definite that she is blind and it took just about a week or less for each from being whitish to becoming blind. I was so surprised for this rapid development and not really sure why it developed that fast. Anyway, as what you have suggested we will visit the vet opthalmologist again this saturday to let her get checked again. Thank you very much again for your help and God bless you! ๐Ÿ™‚

  26. Angeline says:

    I am totally confused. Some say it works, some say it doesn’t. I have a 9 yr old Brittany Spaniel who was diagnosed as being diabetic in April 2013. Her cataracts began to be noticeable about 5 weeks ago. She is a hunting dog, loves being outside and stalking everything she saw that was different. Was so funny to watch her point and stalk a rabbit. She can’t do that any more. My heart breaks every time I give her 2 insulin shots a day and take her blood every evening. Without coaching she goes to her bed in the kitchen, lies down, and puts her head in my lap. So at this point I am willing to try anything to even help her marginally. My point of view is that she really doesn’t have a lot to lose cause she is going blind anyways. What would be a good timeframe to evaluate the effect on her eyes – 2 month. 3 months?
    I also came across an article from Barcelona where apparently there is a product that when injected into an animal[s back legs will have the dog’s eyesight restored.

  27. skeptvet says:

    Your confusions stems from the fact that trying to use anecdotes and individual experiences to decide if a therpay works simply isn’t reliable. You will always find conflicting stories both for and against anything. That is why scientific research is needed, because it can get us to the real answer despite all the errors and biases that make anecdotes untrustworthy. In the case of this product, there is little research, and that which has been done appears to show it doesn’t work. Not perfect, but a lot more believable than “He said/She said” arguments about individual cases.

  28. Angeline says:

    Satn posted on Aug 23/13 that he was trying drops for his dog. I was wondering how things worked.

  29. Caria says:

    NIH Study: This study demonstrates some marginal reduction in lens opacification in a substantial number of cases of canine cataract with the use of a topical nutritional antioxidant formulation including N-acetyl carnosine. Lens opacification was improved with treatment in eyes with immature cataract or nuclear sclerosis while in eyes with mature cataract or cataract with associated intraocular inflammatory pathology less reduction was seen.
    http://www.ncbi.nlm.nih.gov/pubmed/16939459

  30. skeptvet says:

    This is the same study discussed in the post, and if you read that discussion you would see that the author followed it up with another which clearly showed it did not work. Unfortunately, the results of that study have not been published, and I can only speculate that the wishes of the funder may have had something to do with that.

  31. lazarlin says:

    Hi folks.3 weeks now there is a definite improvement to her eyes she,s 9yr old collie with cataracts has been on cansee eye drops there are no more white gakky stuff to deal with in her eyes and a sugary residue is present around the eyes,no great improvement to vision yet ,the scientist says 6 months is usual but a sort of chrystaline formation has formed in the centre of the cloudiness of her eyes,a good sign and she plays ball again!

  32. mrsd803 says:

    @lazarlin
    does the product you’re using have the exact ingredients as mentioned in the study you posted? what is the exact name of the product you’re using and where did you buy it?

  33. mrsd803 says:

    sorry, caria posted the study

    but, lazarlin, did you happen to read that study and then decide to try the drops?

  34. Natalia15 says:

    I adopted female dog on October 2013.She is 10-12 years old and was diagnosed with cataract from trauma.She is on the 3 bottle of Can C eye drops from December 2013.I like to wait couple more weeks and have her eye check .For now I can only say that it did not get visibly worst .Will let you guys know if it improves or not.

  35. GIGI says:

    Surgery, must be the LAST resource for any one, unless it’s life a threatening emergency. The way this country profits from human and animal health is beyond over rated.

    That being said, I obviously always look for the alternatives. I have a 4 year old Schnauzer, that got cataracts a year ago, and his ophthalmologist said that in a few months he would be completely blind but that he would adjust. Obviously his perspective is only limited to surgery and money ($6,000), bottom line to what he was taught in school. The advantage to me was that he is from another country and he completely understands the system here. In his own way, to avoid getting in trouble with his employer, he let me know that surgery was NOT worth it, although my dog was a candidate for it. He didn’t push it.

    A few months before going to my dogs ophthalmologist I began using CAN-C. All I can tell you is that IT DOES WORK! You just have to be very persistent, and follow the instructions thoroughly. Both eyes on my dog were completely white, he was blind! Now one of them has gone back to normal, it’s healthy black again. His other eye, still has about 75% of the cataract, but I also stopped the treatment for a while.

    So far, we are both very happy. I saw a change on his behavior. I can definitely see the difference of the quality of his life now.

  36. skeptvet says:

    Surgery, must be the LAST resource for any one, unless itโ€™s life a threatening emergency.

    Why? It seems that the choosing the right therapy for the right disease is more important than blindly avoiding surgery at all costs as you suggest. In any case, despite your personal experience, the evidence is stronger that this product doesn’t work. A miraculous resolution of cataracts such as you describe should be easy to prove, yet the studies done didn’t find any such response. What is more likely: youre experience was misleading or the clinical research is wrong?

  37. Ophalguy says:

    I have an 8 year old Yorkie with cataracts in both eyes. Vet recommended OcluVet drops intended to “dissolve” the cataracts. I have been in the human eyecare R&D and manufacturing industry for over 20 years with the world leader in cataract care. The only way to have any confidence in a topical therapy is through well controlled clinical studies. None are evident. No one has explained the mode of action for the canine topical drops or how the medication passes through the cornea, passes through the capsular bag holding the lens in place, and then how it “dissolves” the cataract “in situ”. Also, what damage is done to the lens during the “dissolving” of the cataract that is clouding the lens? Human visual examination of an animal’s eye is superficial and does not indicate any level of visual acuity. I am very skeptical of these eye drops. If these drops were proven to be effective, we would have clinical studies in humans already. The only effective treatment in humans is lens replacement. If these drops make pet owners feel better, then the psychological peace may be worth the price and practice of giving the drops to their pets. I pray for peace and comfort for you all and your beloved pets.

  38. mrsd803 says:

    my vet just told me about “ocuglo” drops. she said there’s documented trial information available and that it sounds promising; at least in arresting the progression of cataract. i will be looking it up and reading as much as i can.

  39. karl says:

    Thank you, Gigi.

    My 11 year old Tibetan Terrier has bilateral cataracts, and became functionally blind, a situation that progressed surprisingly fast. Considering his age, surgery did not seem to be a viable option, especially when you consider that surgical cataract repair is never a guarantee, and may actually worsen the animal’s vision.

    On the recommendation of one of our breed rescue contacts, we tried Can-C for two months; the dog is now able to see well enough to catch tossed treats, and the blue haze has almost completely dissipated in one eye–the other eye remains occluded, but to a lesser degree than before treatment. The animal hasn’t said that he can see any better, but his behavior indicates that he can.

    It does make sense to try non-invasive remedies first, providing they don’t do any harm.

  40. dora says:

    I have a male chihuahua I rescued a couple years ago ,age then was around 12 years,I took Chico to the Vet, found out he was heart worm positive said he wasn’t a candidate for a heart worm treatment. I called the rescue and they told me to buy Ivomec and give by mouth instead of injections ,which I did and he seems fine from that ,then they told me they had a tumor removed from his ear,my problem now is that he is getting cataracts and I saw him scratching at his ear ,when I looked at it I saw the tumor has grown back and it was bleeding from where he scratched it with his nails.I’m afraid if I take the chance of putting him to sleep to have the tumor removed he might not wake up.Would there be any alternative to help him other than trying to put him through surgery?

  41. skeptvet says:

    Unfortunately, it really is not appropriate for me to give specific advice about particular patients via the internet. I would suggest you have an open, frank discussion with your veterinarian about your concerns and your options.

    Good luck!

  42. Joelyne Bandorio says:

    My dog is using this for three months there’s a great difference in his vision.. Thanks

  43. Katie says:

    One day I was coming home and saw in the street a beautiful little Papilion..She was so scared because she couldn’t see..I found the owners but they said I could have her..She is 12 yrs old..I read articles on the product Can-C and read many posts from owners of dogs who were using the Can-C in their pets eyes…Every single one had success in getting rid of the cataracts or improving the vision in their dogs..I have been putting one drop three times a day in the eyes of my Papilion for almost three months now..They say it may take as long as nine months before her vision improves..I already have noticed a difference..She was actually staring up at the ceiling fan and can go around objects in her way..She plays outside now for longer periods..I notice the cataract in her one eye looks smaller but the other eye doesn’t look much different..Just breaks my heart..Hey, one good eye is good enough..Have to wait for a few more months to see how she is doing..I will let you know..Thanks

  44. skeptvet says:

    Of course every owner you read reported an improvement. Do you think they would advertise failures? And how many of these dogs had cataracts rather than the far more common lenticular sclerosis that clients frequently bring to me thinking is a cataract? Anecdotes are simply misleading.

  45. Katie says:

    May I ask why you want the Can-C to fail? Maybe it would help the lenticular sclerosis also..Looks like I’m not the only one who has seen a difference as I see from the posts here..Why do you have such a closed mind on this? Reminds me of the doctors years ago who said Vit. E was a waste of money..

  46. skeptvet says:

    Sorry, you’re missing the point. You want this to work, so you overlook the fact that the scientific evidence indicates it doesn’t. That’s how we keep things like astrology alive too, by believing what we want instead of what the evidence shows. It is your mind that is closed to the possibility that things may not be as they seem to you.

    I don’t know what you are referring to as far as Vitamin E. It is useless, and even harmful, when used for some purposes (see this summary, for example) and useful for some other purposes. I don’t see how it has anything to do with your certainty that your experience and belief is correct and anyone who disagrees is somehow closed-minded or misguided.

  47. Katie says:

    You say Vit. E is useless..Excuse me while I have a good laugh..O.K. that is over with..You are relying on the research that was done on the N-Acetylcarnosine..Have you ever tried it on a dog that has cataracts? Why don’t you do your own study on it..?How are you so sure it won’t work? Is it because you believe the research that was done on it..Research also said that silicone was harmless..Let’s see, how many women died because they believed the studies..I know, silicone isn’t the subject here but just wanted to let you know you can’t always rely on studies..

  48. dogowner says:

    So it’s Skeptvet’s responsibility to conduct a study (which takes time, expertise, money, and energy) on each of the dozens of things they have reviewed the evidence for here, but not the responsibility of those who make money off it, or claim it works? The null hypothesis is that most these things which make great claims without putting up better evidence is that they don’t work- any treatment, no matter how ineffective, could have some very convincing anecdotes.

    Trying it on one dog with cataracts is not doing a study, and true believers like yourself would claim ‘ah well it doesn’t work on everyone’, if it was a hundred dogs with cataracts and it worked on none the claim would now be that ‘studies can’t prove everything’ or that the researcher was lying.

    Studies can’t pick up every side effect, because if you only look at, say, 1,000 people you’ll miss a side-effect that happens in one in 10,000.

    Elaborate on the deaths from silicone, cite the studies that ‘said silicone was harmless’ (used in the way women used it who died?) and show that the silicone was used the same way it was done in those studies. The only deaths from silicone I’ve heard of are either freak accidents or people who went to dodgy clinics and had industrial silicone injected. But then how on earth am I supposed to know what you’re talking about when you provide such vague and unsupported arguments?

    http://www.nytimes.com/2014/03/12/nyregion/woman-charged-in-death-caused-by-silicone-injection.html?_r=0

  49. Itai Zoaretz says:

    My almost 15 years old dog is a diabetic dog! and got blind!!! slamming walls …
    The vet said he has cataract and need a surgery (very expensive, and will work for sure),
    After 1 month of drops Can-C, the dog can see!!!
    It works, with well controlled sugar levels, and change in the food diet,
    less dog food, more raw meet!!! That help control the sugar levels!!!

    Say what you want, it works for us!

  50. skeptvet says:

    Well, considering tje clinical trials show it doesn’t work, and testimonials can’t be trusted, we’ll have to agree to disagree.

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