Vetoquinol Enisyl-F Lysine Bites Chicken & Liver Flavored Soft Chews Immune Supplement for Cats, 6.35-oz bag

By Vetoquinol
Rated 3.726 out of 5 stars
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Vetoquinol Enisyl-F Lysine Bites Chicken & Liver Flavored Soft Chews Immune Supplement for Cats, 6.35-oz bag slide 1 of 4
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Vetoquinol Enisyl-F Lysine Bites Chicken & Liver Flavored Soft Chews Immune Supplement for Cats, 6.35-oz bag slide 1 of 4
$25.99Chewy Price
$24.69Autoship Price
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About This Item

  • A highly palatable poultry flavored L-Lysine supplement to support a healthy immune system
  • These small bite sized treats are specifically developed for cats and kittens in mind to treat conditions responsive to Lysine such as upper respiratory problems
  • A nutritional supplement which reduces the severity and duration of symptoms caused by the feline herpes virus
  • Routine administration of these treats will help to reduce herpes flare-ups as well as inflammation of the eyes, conjunctivitis (eye discharge), squinting sneezing, sinus congestion, and so much more
  • Made in the USA and manufactured according to rigorous pharmaceutical standards, L-Lysine powder can be safely administered with no known side effects for as long as required
Play Video: Learn More About Vetoquinol From Our Team of Experts
Learn More About Vetoquinol From Our Team of Experts

Trusted Immune System Support

Adding L-lysine as a supplement to your cat's diet is an easy way to help support her long-term health. As a market leader with a wide range of L-lysine products, Vetoquinol puts this active ingredient in tasty chews and bite-size morsels, plus paste, gel and powder form so you can find the best way to offer it to your kitty. These supplements are specifically designed for felines to support the immune system, and maintain respiratory an

Seal of Quality

Out of thousands of animal supplement companies, only a hundred are audited NASC members, including Vetoquinol. That means they've undergone a comprehensive quality audit to earn the NASC Quality Seal. Displaying this seal on their products means that you can rest assured that they are committed to following the highest current standards of quality in the industry.

Enisyl-F & Viralys Products

Specially formulated Enisyl-F was the first lysine-based nutritional supplement developed for veterinary use for kitties. Supplementing with L-lysine is helpful for managing the symptoms of upper respiratory infections in kittens and cats that were strays, and those in shelters.


Veterinarian formulated to deliver just the right dose in a treat with cheese, chicken, liver and hickory smoke flavors.


Tiny mouthfuls of L-lysine disguised as a delicious snack with savory chicken fat and chicken liver.

Oral Paste

Highly palatable paste that can be given by mouth, mixed with food, or even applied to paws for your cat to lick off.

Oral Powder

Delivers L-lysine HCl in a powder with fish and poultry liver flavors that cats crave—just sprinkle it on top of food.

Oral Gel

Cats only need a small amount of this extremely palatable gel to get the benefits of L-lysine HCl.

About Vetoquinol

Vetoquinol is a family-owned company devoted exclusively to finding innovative solutions for animal health issues. They've shown more than 80 years of dedication, researching everything from oral hygiene to urinary and kidney health to create products that are effective and safe for the pets you love and care about. Founded in 1933 with an expertise in pet pain management and veterinary resources, Vetoquinol has gained the continued trust of pet parents and vets worldwide.
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Top IngredientsArabic Gum, Brewers Yeast, Calcium Propionate...Active Ingredients: L-Lysine, N, N-Dimethylglycine HCl (D mg)....Moisture (max) 11.1% L-Lysine 250 mg Ingredients: l-lysine, natural chicken liver flavor, oat flour...Active: L-Lysine Hydrochloride: 250mg per 1.25 mL., Inactive: Citric Acid, Edetate Disodium...Active Ingredients: L-Lysine Hydrochloride., Inactive Ingredients: Citric Acid, Edetate Disodium...
LifestageAdult, Senior, KittenAdult, Senior, KittenAdult, Senior, KittenAdult, Kitten, SeniorAdult
Health FeatureImmune Support, Respiratory Care, Eye CareImmune SupportImmune SupportImmune Support, Respiratory Care, Eye CareImmune Support
Food FlavorChicken, Liver, Poultry, MeatChicken, Liver, Poultry, MeatFruits & Vegetables, ChickenN/AN/A
Special DietN/AN/AN/AN/AN/A
Food FormSupplement, TreatsSupplementSupplementSupplementSupplement

Questions & Answers

9 Customer Questions

How many chews are there per bag?
Answer by ChewyJan 24, 2018
As this bag is measured by weight, there is no approximate number per bag.

Can the bites and the powder be used together? We've begun feeding wet food only once a day for weight management and our herpes-positive cat is now only getting one dose of Lysine.
Answer by ChewyJun 12, 2018
Before combining any supplements, vitamins, or medications, it's always recommended to consult your vet for the healthiest and most accurate use.

how big are the bites?
Answer by ChewyJan 09, 2019
The treats are approximately the size of a green pea.

I am looking for a crunchy lysine treat for my cat. I purchased soft chews and she refuses to eat it. are these crunchy?
Answer by ChewyOct 11, 2017
These treats are soft chews.

ReviewsWrite a Review

Rated 3.726 out of 5 stars
292 Reviews
Would recommend to a friend

292 Customer Reviews

Rated 1 out of 5 stars
By Kayt on Jun 7, 2022

Too hard to chew

Got this for my cat with chronic respiratory issues to make it easier to give him his lysine. Complete opposite. He LOVES treats but these are so hard to chew I can barely bite through them using all of my jaw strength. He tries to eat them but can’t chew them so he spits them back out. Shame. I’ll try looking for new ones elsewhere. Odin doesn’t approve

Rated 3 out of 5 stars
By Zoomama on Jun 7, 2022

Cat does not like

Vet recommended for rescued cat with suspected Feline Herpes virus. He does not like these and only way he will eat them is if hidden in soft food and then often leaves them. Seem very hard. Not sure if help him or not but hopeful.

Rated 2 out of 5 stars
By SeanR on Apr 9, 2022

Our Cats Would Not Touch Them

We have used the Lysine Gel in our cats wet food so decided to try them on the Lysine bites. We thought since they love their normal treats they would like these. We were sooooo wrong. As soon as I put them out, our cats just sniffed them and backed away. They did try to eat them, but spit them right back out because they are just too hard to chew. I think this could be a great product to help cats, but they need to make the bites a bit more of a softer morsel. Plus, I think having more flavors than just chicken liver wouldn’t hurt either.

Rated 1 out of 5 stars
By Mdorm on Apr 8, 2022

Cat doesn’t like it

1) Doctor recommend to help cat gain weight, but won’t eat it. My mom has to crumble it up and mix with the wet cat food 2) I didn’t put it on AutoShip, but the second one got shipped and I never ordered it!!! That’s not good. It doesn’t show as an autoship, I’m hoping they allow me to return it as my mom still has an almost full bag

Rated 4 out of 5 stars
By LizW on May 12, 2022

Cat likes them, but dosage is extravagant

She's pretty picky, so I'm glad she eats them, but this bag isn't going to last very long if I have to give her *TWENTY FOUR* every day!?!? I dunno if they're gonna help her snots, but i hope so!

Rated 2 out of 5 stars
By Beth on May 17, 2022

Not Helpful

The Cat who is sick & needs it, will not eat it! However, the other 2 cats do like them! But they ARE NOT Soft Chews like the package says! They are hard and crunchy! Money wasted!

Rated 1 out of 5 stars
By crazycatmom on Mar 1, 2022

My cat hated them

I have a cat who was recently diagnosed with chronic respiratory herpes. Vet recommended lysine. He’ll take the liquid but doesn’t like it. Thought I’d try these treats. He hates them. Smells them, tries to cover them up and walks away. And this baby normally loves treats, hard and soft. But not these. Wasted my money and they’re not cheap.Also required to give 12 twice a day. That would be okay but he won’t even take one. I did find a different brand and so far he eats those. They only require 2 twice a day. I mix them in with his regular soft treats. So far so good. But I’ll never buy this brand again except in the liquid.

Rated 1 out of 5 stars
By loopy on Jun 24, 2022

My cats did not like

The Lysine bites for cats we're not liked by two of three of my cats. Would not buy again for the price of them.

Rated 1 out of 5 stars
By Innkeeper on Mar 18, 2022

good product when fresh

This is a very good product for cats. However, this is so hard instead of being soft and chewy my cat won't eat it. It's hard to cut up even with a butcher knife. I tried to cut it in tiny pieces and mixing it with his food. When it is soft and chewy he eats it fine. I feel like I've wasted my money on its expensive price.

Rated 4 out of 5 stars
By RayR on May 24, 2022

My Cat is Not a Fan

These are not a hit with my cat. She will eat one every other week but only grudgingly.