Vetoquinol Viralys Daily L-Lysine Powder for Cats and Kittens, Fish Flavored Lysine Supplement for Cats and Kittens to Support Immune Health, Normal Eye Function and Respiratory Health, 100gm
$31.99





Price: $31.99
(as of Oct 26, 2025 15:27:32 UTC – Details)
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Is Discontinued By Manufacturer : No
Product Dimensions : 4 x 5 x 5 inches; 0.01 ounces
Item model number : 410633
Department : cat-vitamins-supplements
Date First Available : May 25, 2006
Manufacturer : Vetoquinol
ASIN : B000FULBT4
Best Sellers Rank: #1,509 in Pet Supplies (See Top 100 in Pet Supplies) #3 in Cat Multivitamins
Customer Reviews: 4.6 4.6 out of 5 stars 9,250 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
Daily L-Lysine Supplement – Viralys Lysine for cats helps support a strong immune system and can help support eye and respiratory health in cats and kittens of all ages
Supports Feline Health Issues – Vetoquinol Lysine for Cats can help manage common feline health issues and provides support to help a cat’s immune system, ocular health, and respiratory health
L-Lysine for Cats – Viralys L-Lysine for cats and kittens provides specially formulated immune support for as long as needed to help manage conditions responsive to lysine
Vet Recommended – Trusted by veterinarians, Viralys L-Lysine Powder provides a safe and reliable solution for supporting your cat’s immune and respiratory systems.
500mg of Lysine – Viralys Powder delivers the veterinarian-recommended amount of lysine for cats at 500mg 2x daily, and kittens at 250mg
Customers say
Customers find this lysine powder effective for respiratory health, reporting reduced congestion and sneezing, and one customer noting it helps control feline herpes symptoms. The product works well for cats, keeping them healthy and preventing eye issues, with one customer highlighting its outstanding job in maintaining eye clarity. Customers appreciate its palatable taste and consider it cost-effective, noting it saves on vet bills.
13 reviews for Vetoquinol Viralys Daily L-Lysine Powder for Cats and Kittens, Fish Flavored Lysine Supplement for Cats and Kittens to Support Immune Health, Normal Eye Function and Respiratory Health, 100gm
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$31.99


Jenn Reedy –
GREAT FOR FELINE HERPES! LYSINE SUPRESSES THE AMINO ACID ARGININE, RESPONSIBLE FOR FLARE UPS!!!
I work w/ my local VSA ( voluntary services for animals). I took in a few kittens that’s eyes were almost completely shut with crust & their little noses were covered in crust & mucus. A pitiful site 🙁 . I quickly took all 4 to the vet within 24 hrs. WELL, after they said it was “Feline herpes”, (an upper respiratory infection that doesn’t go away but can be controlled) IT ended up costing me close to $800!! With Vet costs, testing costs, & the “Wonderfully expensive” medication they gave me for Each cat, That helped some but not much!! They had liquid meds, meds that had to be put INTO their eyes like 4xs a day, & some other antibiotics. It was awful , & seriously it didn’t help much at all. It lessened it some, but they needed the meds constantly! I looked on the Internet for any info I could find & found out about LYSINE !! I really thought it was a bunch of “bull” but was willing to TRY anything! I 1st bought a paste & a gel- the cats hated it. I then bought this powder. I mixed it into wet food ( not too much or they taste it!) & they ate it! After a week I noticed all their symptoms were really improving! I had STOPPED the Vets meds as the cost was killing me & not really helping them. After a MONTH all the cats were totally better, no crusty gooey eyes, no crusty nose, sneezing, ALL GONE!! I was amazed!! I studied it more, the use of L LYSINE & it’s effects. It surpresses what makes the Herpes virus flare up in the system, so taking it on a Dailey basis means you won’t get the flare up & the full blown symptoms! It also works in humans as well. I kept the kittens & have given them forms of LYSINE for 2 yrs now & they have NOT had another flare up since! If I stopped it for a few months, I noticed some sneezing & gunk in their eyes in the 1st year & quickly put them back on it! With 5 cats ( I had a 3 yr old when I took these in, she caught feline herpes from them as well!) it’s kinda hard to make sure each one gets 250 – 500 mg Ea. When they eat out of each others bowls! So I just put a scoop into 1 3 oz can of wet, feed them 3 cans & it works great. I tried the TREATS, most cats don’t care for them, also many brands you have to give each cat like 10 treats 1-2 x a day! Woa! Or another brand the treats were huge! Only 2 a day because they were the size of a golf ball! Lol. So, the cat powdered LYSINE works good, it’s flavored mixes well in food & good to start on. I had no luck putting this on DRY food, I have heard many ppl do that but my cats wouldn’t eat the food & most just fell to bottom of dish/bowl. I also bought & use HUMAN grade LYSINE 500 mg tablets & crush them up w/ a spoon & mix into wet food. This is VERY cost effective! It taste stronger than this flavored powder, so use a good wet food to mix with & you wont have a problem. My cats got use to it fast. You can also buy LYSINE powder in BULK on here, it’s human grade & already finely crushed up. It works GREAT & cost MUCH less. Plus I like that it’s “human” grade. I now can skip months at a time with no LYSINE & they still get no flare ups. This LYSINE is a God send! I recommend this powder if starting out, it’s flavored and cats will take it well. But cost wise, the pills, tablets, capsule at your store or on here ( cheaper!) are strongest & the best I’ve found( crush up finely) . bitter, but cats really don’t “taste” bitter I’ve heard. Either WAY or BRAND you choose it will all but cure your cats of the virus, you won’t have huge vet bills & expensive meds that are worthless. 5 cats taking LYSINE on & off for 2 yrs and they have NO MORE SYMPTOMS & are very happy healthy spoiled kitty’s… So please do yourself, your wallet, & your cats a favor & put them on a LYSINE regimen of 250 mg a day OR – 500 mg 1-2 x’s a day for a flare up or to start off with. Once symptoms subside, you can stay with 250 mg a day to keep them away for good! Btw, In order to replicate & cause FLARE UPS , in humans & cats the herpes virus needs “ARGININE” another amino acid such as LYSINE . when LISINE is taken at higher doses, it prevents the amino acid ARGININE from over producing & hence preventing outbreaks of the herpes virus. So just check your pets FOODS, TREATS etc for any ARGININE ( L-ARGININE ) in them as this will ADD to your problem!! There ARE foods with this in the ingredient list I’ve found, so just FYI to be safe. Hope this helps someone with the problems I went through & learned from along the way!! 🙂 Jenn ~
Amazon Customer –
Highly Recommend, *Mix* in Wet Food – Vetoquinol Viralys Powder for Cats
I am writing this review after about one month of giving my cats Vetoquinol Viralys Powder daily, and it took about two weeks for their health to start improving. Shipping was on the slow side for Amazon, about a week and a half, but that was posted when I ordered. The Viralys in powder form is very easily *mixed* with wet food, given once daily. I have three cats, all indoor only and over 12 years old. One of the three cats (the one who I’ve only had a year, don’t know her history) was having moderate to bad eye issues, having sneezing fits, and sometimes being even more lazy than usual. Since starting the Viralys her eyes are slowly but surely getting better, she is sneezing a lot less, and she has more energy, being more playful. Every day she seems to be getting healthier. One other cat had developed moderate eye issues recently that was starting to get worse and the Viralys has helped him a whole lot. The third cat isn’t having any health issues, I still give her the supplement. I am very glad I learned about Viralys, and it will always be a part of my cats’ diet from now on. It of course is not a replacement for veterinary care, but it is a great supplement that is helping my pets a lot.Update: I want to clarify, in order for my cats to eat it, it must be mixed in the wet food–keyword mixed. If it is only sprinkled on/in the food, without stirring, they won’t eat it. They have been eating it for a couple months now and all of their health is doing well. Their eyes are better, the sneezing is dramatically reduced, and they have a little more energy than before using Viralys. A little bit went a long ways, the container lasted roughly 10-12 weeks for 3 cats. (Ordering a 2nd container now.)Update 2: Six months later, the cats are doing great. They still have the occasional sneezing or a little bit of sleepy eye, but it is significantly less that before adding Viralys to their diets. I still give it to them in their dinner, most days of the week.
Debbie R. –
Cat magic 🐈
Viralys is magic for boosting your cats immune system amd helping fend off colds. Every cat owner should have this on hand. It has helped my cats get over colds and recover. (Obviously take them to the vet if its severe). For a common cold or malaise, this works fabulously.
Linda Utley –
THIS STUFF IS AMAZING!
Prior to using my cat sneezed all the time, sometimes 15 sneezes in a row! Poor guy! Anywho, he also sneezed big ugly snot balls out of his nose. Not any more!!! It took about a week and he now sneezes maybe once a day, one sneeze, if at all. Snot balls are none existent! Thank you from both of us! 🐈❤️
J Kay –
This stuff is amazing. Fast relief for cat illness.
This stuff is amazing. Sprinkled on dry food and wet food. Our cat colony shared an upper respiratory issue. We were to,d LL-ysine would clear it up, and IT DID! Fast. Got it into 10 cats in two days, thanks to Amazon fast shipping. Just sprinkle it on as directed and the cats lick the plates clean. They love the taste of it.
Chellie Lee –
Still loving this after 20+years!
I’ve used this for over 20 yrs after I got my cat fixed at the pound and it came home with an upper respiratory infection. Now if one of my cats sneeze more than twice in a day, I treat them with a scoop in some wet food where I can be sure they have received a full scoop. I then sprinkle the shared dry food so if anyone else’s immune system is down, this will give them a boost. Cats love the taste so it’s really easy to get them to eat it. It also sticks to dry food so it couldn’t be easier to give. It works great for sick feral cats in your neighborhood especially if going to the vet isn’t an option.
K.Eselin –
Immune system pick up
I have recommend this product in the past to my friends and family who had cats. It works wondersHelp with the cats immune system.I bought this product many times. Helps with colds
Kirsten W. –
A Must Have!!!
Fantastic!!! I know this is a little more expensive than other brands but it literally worked in just a few days to clear up my kittens sneezing! Well worth the money! Product truly worked for my kittens!
Jolyn Ann Wong –
I was recommended to buy this product as my cat had watery eyes and sneezes frequently. After taking this supplement, all is well. I give it to both cats and they liked it maybe because of the chicken and fish flavour.
KATHRYN MOONEY –
Have used product before in jel form and now am trying powder for convenience to add to can food. I think this is a very effective product/supplement. Highly recommend 👌🏻
Angela Conrad –
Awesome. Cats love the taste and I can see an improvement.
Baki –
All my cats are from the shelter, and two of them are from the streets and they all suffer from eye issues, this stuff really helped us keep ontop of their eye health and they look and act so much happier with this powder in their wet food. we will be long time buyers of this product for sure
Baki –
i have a cat with a weak immune system and her eyes are always a problem. This stuff really helped us keep it under control. highly recommend adding this to your cats wet food if they have eye discharge, it makes a great difference