Lysine:                   

What is it?

Lysine is an amino acid recommended by veterinarians to combat herpesvirus outbreaks in cats.  The theory is that Lysine works to suppress arginine production, which the herpes virus needs to replicate. Thousands of cat owners believe that lysine keeps their cat healthy and that as soon as they stop using it the herpes symptoms return.  

Why is it used in cats?

The use of lysine in cats was started because it is used to fight the herpes virus in humans.  The human herpes virus is not the exact same virus as the cat herpes virus, but they are similar in structure. However, the symptoms are different between species.  So, is it actually helpful in cats?

Does it work?

While many cat parents swear that lysine keeps their cats healthy, lysine use in our feline friends is now being questioned.  Studies show that lysine has no effect on herpesvirus in cats, and can make symptoms and viral shedding worse. Are those results seen because the study used shelter cats and shelter cats are under chronic stress?  Do cats living happily in homes see a different response and that’s why owners swear by it?  

Information on the use of Lysine in cats is very confusing for pet owners. After reading all the literature, I decided that pet parents who leave reviews stating that they have used Lysine for years with no problems aren’t lying.  If you look at the reviews on Chewy’s website for Viralys (I’ve included a link at the end of the post), there are hundreds of pet owners who use the product and swear by it. 

Personally, after experiencing the joy of snot rockets glued to the wall and a congested kitty, I decided to try using Lysine and went with the Viralys Gel.  Jackson loved it and willingly licked it off my finger.  It is maple-flavored, so I thought that was odd, but whatever.  He likes it! 

At first, it seemed to work, but after a few weeks his symptoms returned. He still had a slightly runny nose even after months on the Viralys, so I stopped using it.  When he had his recent flare, I bought a Lysine powder in capsules and tried that thinking that a more ‘pure’ form of it might be better. He did show improvement almost immediately, so I am assuming that the powder worked. 

UPDATE: After being on the Lysine for about two weeks, I stopped it just to see if his symptoms got worse.  They didn’t.  So, now I have him on Olive Leaf Extract (which I discuss in other posts), and I’ve added a small pinch of Echinacea powder to it 2ce a day. However, if we have another flare, I am going to do exactly the same things that I did this time, including using the Lysine.

So what do pet owners do?

The debate about lysine rages on and we as pet parents must make educated choices about what is best for our pets.  It seems that lysine has been prescribed for years by veterinarians and is generally considered safe despite recent studies, so I felt comfortable trying it with Jackson.  

I will continue to update this page as more studies regarding Lysine in cats are conducted.

Informational articles:

VetInfo article about how Lysine controls herpes in cats. CLICK HERE

National Library of Medicine study:  CLICK HERE

Glowing reviews of Lysine by pet parents on Chewy. CLICK HERE

We have to pay bills. Please understand that as an Amazon Associate we earn from qualifying purchases.