How often do you supplement L-Lysine and for how long--and for what? And other questions. :)

Tolly , as I said earlier, took l-lysine all his life. For four years he took a therapeutic dose of 500 mg a day, and then I dropped him to a maintenance of 500 mg every other day.

He had up and down liver issues that started in January 2010. We attributed it to 10 years on phenobarbital. He was put on denosyl, and the numbers went down slightly. He went on a two week course of Baytril and everything went back to normal and stayed that way until early spring 2011. (He had blood work every 3 months) Again we put him on a course of Baytril and his ALT went back to normal.

All this time he was still taking his maintenance dose of l-lysine 500 mg every other day.. Kidney function was always normal.

On the day he was diagnosed with an untreatable fast spreading carcinoma, still, all organ function was normal.

I won't ever know, of course, if the life time taking l-lysine caused any of his other issues. His "hairball sicknesses" which became more frequent as he got older, I often still wonder about those. I still think it was a motility issue. But, if he didn't take the l-lysine, he would have lost his eyes. And who is to say, once his eyes were taken out, if the virus would manifest in some other way. Constant URI for example. When I took him off the l-lysine once, in a week his eyes became red and inflamed and full of discharge again. So I would not have changed a thing, even after reading all this.

We have to remember, that for our cats, quality of life is the most important thing. They don't think about longevity. If a cat has a severe herpes infection, and l-lysine is the only thing that can keep him healthy, in my opinion, it is worth any risk.

If there is something else that can be used....that's a good thing. But don't know if there is, herpes being a viral infection, with no cure.

WhollyCat, thank you, very much, for that information!  

So now, that I have a better understanding, a few thoughts come up.  The general consensus is, the normal dosage, goes by the weight of the cat. Under 9 lbs, 250 mgs once a day. Over 9 lbs, its 250 mgs twice a day, or 500 mgs once a day. For right now, we will leave kittens out of the discussion. My vet has even said this.

So I am wondering, if given a dosage, higher than that, is what is causing the issues in kitties? Or giving L-Lysine, when its really not needed, as in, the kitty is not sick, or stressed.  Or maybe it makes a difference, weather its given twice a day, or once a day?  Maybe, in Feralv's case,  1000 mgs is too much?

I can see why show people, who run heavily, give it all the time, the constant traveling, different show halls, stuff floating around the show halls, handled all day by judges, when their normal routine, is to take nappys all day, tires and stresses the kitty, and thus lowers their immune system.  Kinda like when we get stressed, it lowers our immune system, and thus, makes us more prone to catching illness's.

Most supplements, do their intended job, if given in the correct dosage. Yes there are occassions, when a vet will advise a higher dose of meds or a supplement, depending on the medical issue.  

Forgive me, while I digress to the horse world, lol, have shown horses, since I was a little kid, which is about a hundred years ago, lol.  In the horse world, there are about a zillion supplements, some of them work, most, do not. You also have to look at the ingredients. In most cases, the lower the dosage, the more pure, it is, and not full of fillers and junk, as in, higher dose, run out quicker, buy more, more money for the companies.

Most horse people, tend to over supplement, they believe the ad, when in most cases, just feeding a good quality grain and hay, is all one needs. We in the horse world, stress, know why you are supplementing, what, exactly, are you trying to accomplish?  This part gets fuzzy, its been awhile, but with horses, you have to be extremly careful, you are not upsetting the balance, similiar to what you just described, you can cause more harm, than if you did nothing.

So, would it not be the same with cats?

One needs to understand, the nutritional balance, what they are feeding. They need to know, why, they are giving a cat a supplement, what are they exactly, trying to accomplish?

In most cases, unless the cat has a medical issue, or is a show cat, just feeding a good quality grain free, gluten free, by product free feed, is enough.  

OK, getting tired, lol, rambling more than normal, lol.  Again, thank you for the information. Now I can have an intelligent conversation, with my vet on Friday, lol.   

One more thing, about horses, then I will shut up about it, lol.  If your cat or dog, gets sick, ya put them in the car, and take them to the vet. With a horse, ya can't just throw them in the backseat, lol.  Horses also can't throw up, like cats or dogs. They colic, in alot of cases, they die.  Having a sick horse at home, is bad enough, having a sick horse, at a show, is, your major sca-rood. So horse show people, have to be very knowledgeable about horse feed and supplements.  They have to know about proper balance in nutrition, they have to know, what they are supplementing for, and how it affects the balance.

So, wouldn't it follow the same, with cats?        

Sugarcatmom said:

Just on my way out the door but I recall finding this study in some previous research I did on this topic: http://jn.nutrition.org/content/134/8/2042S.full
 

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I saw that study, and towards the end of it it says:

"The mean body weights of the cats did not differ significantly among or change within the dietary treatment groups throughout the study. However, there was a reduction in food-intake amount in the cats that consumed 111 or 131 g of lysine/kg of diet, and by d 14, this difference approached significance. A longer study period may have yielded a statistically significant difference. Two likely causes for this reduction in food-intake amount are the increased quantities of water needed to incorporate the higher amounts of lysine into solution in the 111 and 131 g of lysine/kg of diet concentrations, or toxic effects of high concentrations of lysine in these two diets. There was no change in dietary dry-matter intake when equivalent amounts of water only were added to the basal diet. Therefore, the reduction in food-intake level in the cats that consumed 111 or 131 g of lysine/kg of diet was most likely the result of the excess dietary lysine and not the water used to incorporate it into solution.

It is hypothesized that the reduction in food intake in this study was the result of an amino acid toxicity. A reduction in food intake can be the result of amino acid imbalance, toxicity, or antagonism (12). Excess dietary lysine was shown to antagonize arginine in chicks (13), rats (14), guinea pigs (15), and growing dogs (9). An amino acid imbalance resulting in a reduction in both food-intake and weight gain was reported for young pigs that consumed diets that contained 34.5 or 46.5 g of lysine/kg of diet and 5.3 g of arginine/kg of diet (11). A reduction in food intake coupled with the absence of reduced plasma amino acid concentrations and clinical signs of arginine deficiency support an amino acid toxicity at the two highest dietary lysine concentrations fed in this study."

So perhaps that leans towards the high amount of lysine supplemented being a problem with appetite? If it would have been a longer trial, maybe weight loss would have been observed? Maybe other issues would have been observed?

This is the only study that I've seen that says that excess dietary lysine does not cause lysine/arginine antagonism. It was such a short study that it does concern me that kitties weren't eating as much in the end. Wish they would have done a longer time-span, then I would be more confident in their findings. JMO, but maybe it does show that short-term use may be appropriate? This is kind of inline with what the author in the link said:

"Determination of the safety of lysine supplementation is imperative due to cats' exquisite sensitivity to arginine deficiency (6). Although previous studies demonstrated that exogenous supplementation with lysine increases plasma lysine without antagonizing plasma arginine concentrations (3,4), the effect was short lived (3 h) in the one study where it was evaluated (3). It is hypothesized that if the lysine content of a commercial diet was increased, cats consuming that diet ad libitum would have and maintain elevated plasma lysine concentrations throughout the day and forgo the variable concentrations observed with exogenous supplementation. This consistent elevation in plasma lysine concentrations may be beneficial in controlling FHV-1. However, to the authors' knowledge, the safety of lysine administration >19 g/kg of diet (7) has never been evaluated. The objective of this study was to determine the safety of excess lysine supplementation to a commercial-type, expanded diet fed to healthy adult cats."

What I haven't spent the time to figure out yet is how much lysine was being given on a daily basis in that study? The numbers referenced were GRAMS, not milligrams.

I have given 500 mg a day starting about a week  before a show to certain cats who have had in the past a tendency toward herpes flare ups then continue for a week..   but  I don't usually show more than about once a month so that would end up 2 wks on, 2 wks off. 

 During a  herpes flare up I have given 1000 mg a day,  or even  2000 a day in a bad outbreak.   All this was on advice of my vet. who on the one hand said that during an outbreak I could give  those high amounts. but shouldn't continue those amounts as maintenance forever .

&  I thought that was a lot --  but WOW !  The 131 g per kg they used in that study would be a seriously huge amount!   Not to state the arithmetical obvious, but  I would be giving my 4 kg cat 524,000 mg  a day!   I don't wonder it might cause some kinda toxicity or imbalance! 

LDG said:

What I haven't spent the time to figure out yet is how much lysine was being given on a daily basis in that study? The numbers referenced were GRAMS, not milligrams.

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:lol3: Good.... I was hoping someone with a brain would figure that out for me

Nope, your brain is just fine, Lauren. That's why I said the high amounts in the foods causing the lack of appetite, because that is awfully dang high re grams per kilogram (2.2lbs) of kitty.

maewkaew said:

... &  I thought that was a lot --  but WOW !  The 131 g per kg they used in that study would be a seriously huge amount!   Not to state the arithmetical obvious, but  I would be giving my 4 kg cat 524,000 mg  a day!   I don't wonder it might cause some kinda toxicity or imbalance! 

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Right? Was that how much was given daily?

LDG said:

Right? Was that how much was given daily?

Click to expand...

131 grams = 131,000 mg per kg of kitty equals 59,545 g per pound. I think. My brain is fried. Way high, but that is the only study I'm finding/I've found on lysine not being an antagonistic to arginine when arginine is in the diet. Not sure what is up with that.

Logically thinking of the whole process that goes on with amino acids interacting and converting to enzymes, etc., how can lysine in high amounts (but not as high as that study) not throw off the balance of things? Know what I mean?

I found this information at vetinfo.com, which explains in layman's terms how l-lysine works and in part its affect on arginine. It makes sense to me.

"How Do L-Lysine Supplements Work?

Viral infections grow when an individual virus takes control of a host cell and makes it use its resources to manufacture more viruses. The virus does this by injecting its DNA into the nucleus of the host cell. This strip of genetic material contains instructions that the cell's chemical machinery can use to build more viruses. The host cell, unable to distinguish between the viral DNA and its own, will continue to make more viruses until it bursts, releasing the viruses into the body to infect more cells.

An uninfected cell usually does not use much of a particular amino acid called arginine, while cells that are infected use a lot of it to make more copies of the virus. The cell's natural chemical process that uses arginine is limited by the quantity of L-Lysine (another amino acid) that's available. By giving daily L-Lysine supplements to your cat, you increase the quantity of L-Lysine available for the cat's cells to use, which means that the cell uses more arginine for its natural functions. This leaves less arginine available for the production of the cat herpes virus, thereby slowing the growth of the infection."

It doesn't say what dose of l-lysine is acceptable, or how much arginine must be in a kitty's diet so as not to deplete arginine. But, this does make sense because so many kitties are on l-lysine long-term without seeing signs of arginine depletion. Just me, but if I had a kitty with FHV, I would give a higher dose during times of initial onset and then taper the dose to a maintenance dose for a week after improvement. Me, I'm a cautious sort of gal, so this I would be comfortable with.

I'm still digging information up, but I found this to in a sense support using l-lysine--with my own self-limiting dosing schedule because I still question how much and for how long, plus my questions about kitties with kidney and liver issues.

That's VERY interesting! And yes, that addresses the lysine-arginine agonist issue - and why it appears to not be a problem with long term lysine use in kitties with the herpes virus. Thanks for all the digging!

I think the study that was linked to earlier (I also linked to it in my earlier reply) was giving the amounts of lysine in grams per kg of food. Obviously the cats are not eating a kg+ of food daily, so they were not getting the full amount given per kg daily. To find out how much lysine those cats were getting you would have to look up how much food it says they were eating each day and use the info given to calculate the amount of lysine in the food.

To find out if the amount of lysine in a supplement could really be enough to deplete the arginine available in the diet, you would have to know how much arginine (and lysine) is in the cat's diet, how much food they are eating each day, and then you would have to know the rate or amount at which lysine competes with arginine in the cats' system. I haven't been able to find a lot of info on that last point so I am not sure if the amount of lysine that is given in supplements is actually enough that it could totally out-compete the arginine in the diet to the point where it would cause health issues.

The other thing to note is that in order for lysine to completely out-compete arginine in the diet, it must be present in ALL meals the cat eats, so if the lysine is not given in every single meal then it is not going to be causing the type of problems seen in a diet where arginine is totally absent or in a cat that is unable to process arginine, because the cat has meals where the arginine has no 'competition' with the supplement.

Possibly it would take a larger amount of lysine to actually completely out-compete the arginine to the point of causing health issues, and this is why vets are not worried about over supplementation and recommend it for a lot of cats?

WhollyCat said:

I found this information at vetinfo.com, which explains in layman's terms how l-lysine works and in part its affect on arginine. It makes sense to me.

"How Do L-Lysine Supplements Work?

Viral infections grow when an individual virus takes control of a host cell and makes it use its resources to manufacture more viruses. The virus does this by injecting its DNA into the nucleus of the host cell. This strip of genetic material contains instructions that the cell's chemical machinery can use to build more viruses. The host cell, unable to distinguish between the viral DNA and its own, will continue to make more viruses until it bursts, releasing the viruses into the body to infect more cells.

An uninfected cell usually does not use much of a particular amino
acid
called arginine, while cells that are infected use a lot of it to make more copies of the virus. The cell's natural chemical process that uses arginine is limited by the quantity of L-Lysine (another amino acid) that's available. By giving daily L-Lysine supplements to your cat, you increase the quantity of L-Lysine available for the cat's cells to use, which means that the cell uses more arginine for its natural functions. This leaves less arginine available for the production of the cat herpes virus, thereby slowing the growth of the infection."

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:lol3: Thank you for the above AND I just got off the phone with Dr. Denise Lindley - Animal Eye Specialist in Elgin, IL (and three other chicagoland locations) who has been treating Perla for months. She basically explained to me the above but a shortened version. She also demanded that I keep Perla on 1000 mg. per day - divided into two doses of 500 mg. twice daily. This IS a maintenance dose and is in accordance with all of the literature and studies she has done and researched for a very long time. She said that you can give UP TO 25 times that amount and it will still not be toxic. She also said LONG TERM use for any Herpes kitties is a must. Very, very important and she reiterated this to me. I will also be bumping up Pipsqueak as I have only had him on 500 mg. It is best in a household of cats when one or two is shedding the herpes virus to keep ALL kitties on the Lysine daily.

She had to laugh at me... she asked right off the bat "SO, you have been doing your own internet searching " I told her about the cat site and that her information might help others with herpes kitties to know that that dose of Lysine is the correct dose. Not less - as most vets tell their clients. Anything under 500 mg. twice daily will not be enough to ward off the herpes virus either optic or respiratory. At that dosage, there will be no ill effects on any kitty with kidney or liver disease either. Perfectly safe and GOOD to use for all kitties.

SO I am very, very much relieved and feel very confident in keeping up with my Lysine regime.

So then I should double the amount they are getting now (500 mg daily each) since Silly has the virus? 

Nekochan said:

The other thing to note is that in order for lysine to completely out-compete arginine in the diet, it must be present in ALL meals the cat eats, so if the lysine is not given in every single meal then it is not going to be causing the type of problems seen in a diet where arginine is totally absent or in a cat that is unable to process arginine, because the cat has meals where the arginine has no 'competition' with the supplement.

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Good point.

As to the math....

131g of L-lysine per kg of food.

So if my brain is working correctly (and I'm not sure it is), that's 131,000mg of lysine per 1,000g of food. With 28.35 grams to an ounce, and 35.27337 ounces per kg, that works out to 3,713mg of lysine per ounce of food? Most of my cats eat 4.5 ounces of food a day.

Clearly (if my math is right) they were were testing upper limits of safety. :lol3:

Feralvr said:

WhollyCat said:

I found this information at vetinfo.com, which explains in layman's terms how l-lysine works and in part its affect on arginine. It makes sense to me.

"How Do L-Lysine Supplements Work?

Viral infections grow when an individual virus takes control of a host cell and makes it use its resources to manufacture more viruses. The virus does this by injecting its DNA into the nucleus of the host cell. This strip of genetic material contains instructions that the cell's chemical machinery can use to build more viruses. The host cell, unable to distinguish between the viral DNA and its own, will continue to make more viruses until it bursts, releasing the viruses into the body to infect more cells.

An uninfected cell usually does not use much of a particular amino
acid
called arginine, while cells that are infected use a lot of it to make more copies of the virus. The cell's natural chemical process that uses arginine is limited by the quantity of L-Lysine (another amino acid) that's available. By giving daily L-Lysine supplements to your cat, you increase the quantity of L-Lysine available for the cat's cells to use, which means that the cell uses more arginine for its natural functions. This leaves less arginine available for the production of the cat herpes virus, thereby slowing the growth of the infection."

Click to expand...

:lol3: Thank you for the above AND I just got off the phone with Dr. Denise Lindley - Animal Eye Specialist in Elgin, IL (and three other chicagoland locations) who has been treating Perla for months. She basically explained to me the above but a shortened version. She also demanded that I keep Perla on 1000 mg. per day - divided into two doses of 500 mg. twice daily. This IS a maintenance dose and is in accordance with all of the literature and studies she has done and researched for a very long time. She said that you can give UP TO 25 times that amount and it will still not be toxic. She also said LONG TERM use for any Herpes kitties is a must. Very, very important and she reiterated this to me. I will also be bumping up Pipsqueak as I have only had him on 500 mg. It is best in a household of cats when one or two is shedding the herpes virus to keep ALL kitties on the Lysine daily.

She had to laugh at me... she asked right off the bat "SO, you have been doing your own internet searching " I told her about the cat site and that her information might help others with herpes kitties to know that that dose of Lysine is the correct dose. Not less - as most vets tell their clients. Anything under 500 mg. twice daily will not be enough to ward off the herpes virus either optic or respiratory. At that dosage, there will be no ill effects on any kitty with kidney or liver disease either. Perfectly safe and GOOD to use for all kitties.

SO I am very, very much relieved and feel very confident in keeping up with my Lysine regime.

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Lauren, thank you so much for talking to Dr. Lindley about this!

So it seems Billy is still a sneezle because his dose of lysine isn't high enough! :lol3:

And Jules? I'm really glad you brought this all up. It's important we're aware of the issues. I know you're still researching, but I think the answer about the lysine-arginine agonist action lies in the diet and amounts of each.... and apparently cat food contains enough arginine for long term use of lysine to not be a problem (other than in some rare cases? ).

catspaw66 said:

So then I should double the amount they are getting now (500 mg daily each) since Silly has the virus? 

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Yes - according to this specialist - and you can probably even call for a consult :lol3: I do know that people drive for many hours from other states to see her. Lysine for herpes control should be 500 mg. am and 500 mg. pm. I was surprised as well when she told me this back in April when I first brought Perla to her for her herpetic eye. My poor rincess: I thought I was being SOOOO smart by telling Dr. Lindley that Perla was getting 500 mg. per day of Lysine and said that was the maintenance dose. She said NOPE...... 1000 mg. is. This coming from a brilliant specialist who treats herpetic eyes all day long. I doubt she would recommend this to her clients if it were not true, unsafe or toxic long term. She if very, very specific and detailed about her instructions.

LDG said:

Lauren, thank you so much for talking to Dr. Lindley about this!
So it seems Billy is still a sneezle because his dose of lysine isn't high enough! :lol3:
And Jules? I'm really glad you brought this all up. It's important we're aware of the issues. I know you're still researching, but I think the answer about the lysine-arginine agonist action lies in the diet and amounts of each.... and apparently cat food contains enough arginine for long term use of lysine to not be a problem (other than in some rare cases? ).

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Sure, I enjoyed talking with her. :happy3: Yep - bump up Billy. Perkins was sneezing last week REAL bad and I have not been giving him the Lysine. Bad momma..... Anyway, started him up on 500 am and pm. and his sniffles are all gone. I am certain that Perkins is also a herpes kitty and was very, very sick as a kitten at three weeks. Almost died. :sobbing: Even Presley from time to time will get a very weepy right eye. So I think those three siblings all have the herpes virus and unfortunately Perla's virus is attacking her eye. BUT she IS doing better since seeing Dr. Lindley. My little angel :heart3: :rub:

Jules - I do so appreciate you bringing this to light. I did get a bit worked up and concerned :lol3: and frustrated only because it seems that whenever we try to treat our babies with whatever, there is always some sort of side effect or negative effect. Now we know, though, that the Lysine dose we are giving our babies is safe.

p.s. Dr. Lindley did say we should all be worried more about how vaccines effect the kidney and liver. She also told me to never, ever vaccinate any herpes kitty, ever. The sad thing is.... and I have a thread on Perla in Health somewhere - was that back in December, Perla received her distemper vaccine. Two weeks later she was in the hospital with a full blown herpes viral infection. She had a weepy eye the day she received her vaccine :sobbing: and the vet (not my Dr. Mark) my TNR vet - said "oh no problem, she can still receive the vaccine" THAT is why I am now dealing with a more serious eye issue with my baby. Lysine will save her eye in the long run. :cross: Perla.....

Feralvr said:

Anything under 500 mg. twice daily will not be enough to ward off the herpes virus either optic or respiratory. At that dosage, there will be no ill effects on any kitty with kidney or liver disease either. Perfectly safe and GOOD to use for all kitties.
SO I am very, very much relieved and feel very confident in keeping up with my Lysine regime.

Click to expand...

But Lauren..Shouldn't these dosages be taken on a cat to cat basis?

Tolly was on a maintenance dose of 500 mg every other day for 6 years. And a therapeutic dose of 500 mg a day for the first four years. He had a very dramatic improvement when I first started him on it. His eyes were like worst case scenario pictures you see in feline herpes articles. By the fourth day on the 500 mg a day, his eyes were clear and dry and..perfect. It was incredible! I remember it as if it was yesterday, but even if my memory was poor, I have the cat journal to look back at. It's all there, I recorded every day "eyes swollen red, goopy", "eyes swollen red goopy" "eyes red..right eye looks better?" and on the fourth day "Eyes clear!"

This was 11 years ago, and I think l-lysine was a relatively new treatment for feline herpes in cats. Tolly saw an ophthalmology specialist at Cornell after I'd had him to every vet in the area almost. I don't think they had all those pastes and gels they have now. I used Source Naturals pure powder right from the start.

It's good to know, if a cat needs a higher dose, it is safe for the cat to have it. But perhaps not every cat needs 1000 a day to offset flare ups, and 500 a day in maintenance.

However I hope that more vets will update themselves to know that a higher dose may be more effective. I've seen more than a few threads where people said "the l-lysine hasn't helped at all" I always wonder about compliance when I see that, I have to admit. And I wonder how effective those gels and pastes and treats, with all the other junk added, really are. But now I wonder if those cats just need a higher dose.

Unless, perhaps..is it possible for this virus to build up a resistance? Is it possible that after 11 years or however many years this treatment has been in use, the dosage has had to be increased to control the herpes virus?

Incidentally, Ootay and Bibbs never caught the herpes virus from Tolly, even though they slept face to face most of the time. They were vaccinated of course, and I see by my notes that I asked the vet I was using then if I should give them the L-lysine too. She said I should, but it was short lived as neither would tolerate it. (I was dissolving it and syringing it in those days) Whew. Reading over those old notes is not easy. It's not just his herpes trouble, but when his seizures started. Awful awful time.

I'm sure, that as with any supplement, it's best to start with the lower dose, and if kitty doesn't respond, then increase the dose. And now we know, the dose can safely be increased to 1000mg (or twice that during a flare-up) daily.

Hmmm...  I have read this entire thread and done some research on my own.  Now I am more confused than ever.  Is 500mg too much as a maintenance dose?  I give my 500mg daily.  I wonder if I should reduce that to 250 and see what happens.