Vetoquinol Viralys Powder Immune Supplement for Cats, 3.5-oz

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At a Glance

  • Immune Support
  • Eye Care
  • All Lifestages

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About This Item

Details

  • A highly palatable L-Lysine HCI Nutritional oral powder for cats that may be sprinkled over dry food or mixed with a small amount of canned food.
  • For cats and kittens as a nutritional supplement for conditions responsive to Lysine such as upper respiratory problems or feline herpes.
  • This powder will also help reduce inflammation of the eyes, conjunctivitis (eye discharge), squinting sneezing, sinus congestion, and so much more.
  • This L-Lysine supplement is specifically developed for cats and kittens and contains naturally occurring amino acids.
  • Manufactured according to rigorous pharmaceutical standards, L-Lysine powder can be safely administered with no known side effects for as long as required.

Ingredient Information

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Questions & Answers

34 Customer Questions

I only feed the neighborhood cats once daily, so can I double the dosage to do this?

Answer by Kymm • Dec 19, 2025
I only give this as a supplement to my cats once per day and it definitely has an impact. Their coats are shiny, their eyes are bright and they are very healthy.

Can I give this to my cat as a supplement if they are healthy?

Is there any difference between L-Lysine and L-Lysine HCL. We have been giving our cat L-Lysince, but I see that Chewy only has L-Lysine HCL.

Answer by Chewy • Jul 29, 2018
The HCl denotes that the lysine is present as the hydrochloride salt. Salts changes the properties of the lysine, making it more soluble.

Towards the end of the Viralys, there is tan/brown powder. Is this safe to use or should I throw it out?

Answer by Chewy • Aug 31, 2021
The tan or brown powder is flavoring. It tends to fall to the bottom of the tub over time. It's recommended to shake the tub before every use to keep it mixed.
Reviews
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4.7
Rated 4.7 out of 5 stars
1886 Ratings
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Customers Mention

Chewy identifies key considerations with the help of artificial intelligence and our veterinarians.

Effectiveness

91% Positive

Form and Administration

88% Positive

Ingredients

91% Positive

Nutritional Value

90% Positive

967 Customer Reviews

Rated 4 out of 5 stars
By Katrina on Dec 28, 2025

Vet Recommended

This was recommended by my vet after a surprise visit due to my cat coming down with the Feline cold (sneezing, coughing, lethargic, etc). I was directed to administer

This was recommended by my vet after a surprise visit due to my cat coming down with the Feline cold (sneezing, coughing, lethargic, etc). I was directed to administer one scoop twice a day in her food. My cat eats wet food so this has been very easy, with no fuss from her. Chewy’s price is significantly cheaper than my vets pricing, which I truly appreciate. I would purchase this product from Chewy if needed agin. My cat has been on this supplement for over two weeks, going on three. Over this time, her symptoms have slowly subsided but have not completely gone away. I will continue the supplement, as they do provide relief, but may ask my vet for something different if her symptoms do not completely clear.

Rated 5 out of 5 stars
By Joyce on Jan 14, 2026

Works Great

It boosts the immune system to help fight against URI etc. It has worked with many of my cats that has slight symptoms - sneezing , runny nose , goopy eyes - just

It boosts the immune system to help fight against URI etc. It has worked with many of my cats that has slight symptoms - sneezing , runny nose , goopy eyes - just sprinkle the advised dosage into the their food . Within 24-48 hours a huge improvement . They like the taste so no problem getting them to eat it in their food. This will not stop URI that has already created issues - that needs vet care . Viralysis helps with prevention

Rated 5 out of 5 stars
By Robert on Dec 27, 2025

Feline AIDS help

I have three outside cats with feline AIDS. This product is great in easing the upper respiratory problems these cats suffer with. I use it every day on top of wet

I have three outside cats with feline AIDS. This product is great in easing the upper respiratory problems these cats suffer with. I use it every day on top of wet cat food. The cats still devour the wet food, but the medication helps cut down on breakouts of respiratory problems. The more it’s part of the daily regimen, they don’t have nearly the problems they have without it.

Rated 5 out of 5 stars
By Denise on Nov 26, 2025

No more sneezes!!

When I adopted my two Maine Coon babies and brought them home, they sneezes all the time! I called the shelter and asked how do you guys stop kitty sneezing? They

When I adopted my two Maine Coon babies and brought them home, they sneezes all the time! I called the shelter and asked how do you guys stop kitty sneezing? They told me they use Viralys powder on all the kittens. I bought the immune powder and put a tiny ( it comes with a tiny spoon) bit on their wet food and I was amazed all the sneezes stopped! They do not notice it in their food. I will use this powder throughout their life. The powder is a little expensive but it lasts nearly a year for 2 cats! To me its a bargain!

Rated 5 out of 5 stars
By Madeline on Jan 14, 2026

Life saver!

This product along with eye drops helped get rid of my cat’s eye irritation. I was given this years ago from a vet when our other cat had conjunctivitis, so I was

This product along with eye drops helped get rid of my cat’s eye irritation. I was given this years ago from a vet when our other cat had conjunctivitis, so I was very happy that I could buy this from Chewy without a trip to the vet. It came super fast!

Rated 3 out of 5 stars
By Kim on Dec 18, 2025

Cats notice I added this to their food

This is the 2nd item with Lysine I have tried for my cats because my vet recommended I add to my cats' diets. My cats normally eat most poultry type products, so

This is the 2nd item with Lysine I have tried for my cats because my vet recommended I add to my cats' diets. My cats normally eat most poultry type products, so I can only assume they are not liking the fish flavors in these products. I think I found one more product with Lysine that is chicken based that I may try before giving up. I was so wanting them to like this product.

Rated 5 out of 5 stars
By JC on Dec 23, 2025

Helpful preventative

As my cat has gotten older, she's gotten a few colds that lingered. My vet recommended giving her this twice a day to boost her immune system and prevent future

As my cat has gotten older, she's gotten a few colds that lingered. My vet recommended giving her this twice a day to boost her immune system and prevent future colds. She eats it easily mixed in her food (she loves most food so this is not normally an issue for her) and so far it has worked at preventing more colds.

Rated 2 out of 5 stars
By Bunnymum on Dec 17, 2025

No results...

I had such high hopes for this! But sadly its been several months and I haven't noticed any positive results in any of my kitties. They still have eye gunkies and

I had such high hopes for this! But sadly its been several months and I haven't noticed any positive results in any of my kitties. They still have eye gunkies and sneeze etc I will have to try something else. I would definitely give it a try thought because every cat is different and atleast this is simple to add to a routine!

Rated 5 out of 5 stars
By Alyssa on Nov 14, 2025

Life Saver for cat with squinty eyes

My cat has always struggled with a puffy and inflamed eye that caused her to constantly have a squinty eye, especially when stressed. After giving the powder consistently,

My cat has always struggled with a puffy and inflamed eye that caused her to constantly have a squinty eye, especially when stressed. After giving the powder consistently, her symptoms have been reduced greatly. It is still slightly enflamed but she no longer squints it, even after an 8 hour move. She also eats it in her wet food no problem, which is surprising as she is picky. No side affects. It does not take away whatever it is that causes the problem (the vets don’t know and no cream ever worked) but it definitely alleviates her pain!

Rated 3 out of 5 stars
By Elisha on Dec 31, 2025

Cat doesn't like it

Vet recommended this product to address my cat's respiratory problems. So far no change but it is hard to tell because he doesn't like to eat it - can't tell if

Vet recommended this product to address my cat's respiratory problems. So far no change but it is hard to tell because he doesn't like to eat it - can't tell if it is the flavor or the texture he doesn't like. I tasted it and it is very bitter.