L-Lysine For Cats And What It Does

Cats get sick from time to time.

But what can you do against it? How should you treat your kitty when she is walking around coughing, sneezing and simply not feeling well?

In the past, L-Lysine has been considered a valid supplement for kitties to strengthen their immune system. Today we’ll take a closer look at L-Lysine and tell you what you need for when your cat gets sick.

Let’s jump right in.

What Is L-Lysine?

L-Lysine is an essential amino acid, an organic compound that neither cats nor humans can naturally synthesize. If administered through food, the compound supposedly helps with the biosynthesis of proteins and other crucial body functions.

Why Is L-Lysine Relevant For Cat Owners?

Upon getting sick, cats often suffer a respiratory infection or even worse, get infected with the feline herpesvirus type-1 (FHV-1).

When initially researched, L-Lysine studies suggested that the compound is a valid treatment for FHV-1 in cats. In conclusion, L-Lysine seemed to suppress the virus, reduce the intensity of the symptoms and overall help the cat deal with the disease. Results weren’t clear though and further studies needed to be conducted to be sure about the effect of the compound on cats.

However, combined with the lack of other treatment options, veterinarians started to prescribe it as a treatment for cats infected with FHV-1 and other infections.

Although the results weren’t backed up by studies consistently, it seemed like the compound was helping the infected cats. Owners reportedly stated that the treatment was successful and that they couldn’t identify any downside.

Naturally, veterinarians kept prescribing the product.

For a long time, it was therefore believed that L-Lysine can, in fact, help your sweetheart get back to health faster. When asked in 2015, over 90% of veterinarians stated that they recommended the use of L-Lysine as a treatment for FHV-1.

Not anymore though.

Does L-Lysine Help Your Cat?

Published in 2015, a comprehensive study researching the behavior of FHV-1 when exposed to L-Lysine found no evidence of the substance’s positive influence on the virus whatsoever. The effect on other infections was equally non-existent.

But there is more…

One study even shows that Lysine therapy led to a worsening of the symptoms of FHV-1, causing the cat to suffer even more from the disease!

The authors and scientists of the study were shocked at the results and urged all veterinarians to stop using the compound as treatment.

In addition to those findings, other researchers were able to identify the side effects of L-Lysine clearly. While these are not fatal, they surely are uncomfortable for the cat and have a negative impact on health and well-being. These side effects include:

  • Vomiting
  • Seizures
  • Diarrhea
  • Nausea
  • Swellings
  • And more

Combined with the negative side effects the amino acid can cause, Lysine does not seem to help cats with infections.

Is L-Lysine Bad For Your Cat?

While newer studies suggest the opposite, there is anecdotal evidence that the substance helps in curing respiratory infection and FHV-1. The positive reports of cat owners do exist, and there are still people today that swear L-Lysine helped their cat get healthy again.

Supporters of the substance also claim that although the side effects aren’t pleasant for the cat, they are still more bearable than the virus itself.

The bottom line is, however: L-Lysine isn’t scientifically proven to do any good for your cat’s health.

While user testimonials can be helpful in determining whether something is good or not, it is not advisable to depend on them, especially when it is about something as serious as your cat’s health!

Because of that, we advise you to lay it off and switch to an alternative.

Alternatives Feline Herpes Treatments To L-Lysine

As with humans, once cats get infected with the herpes virus, it will remain in their system for a lifetime. Therefore, if your kitty gets diagnosed with feline herpes, you will most likely be fighting the virus forever.

But how?

It is important to know that although you can barely fight the virus itself, you can effectively fight its symptoms! To do that, there are a few things you need to consider.

First, make sure to feed and nourish your kitty sufficiently. Cats’ immune systems are crazy strong and can withstand a lot; so make sure to supplement it with enough food and water! Mix in some healthy cat treats to make sure your cat is getting all the minerals and vitamins it needs.

Second, create a calm, loving and relaxing environment for your cat. Make your cat feel good, groom it regularly and let it rest. Since stress encourages virus growth by weakening the immune system, a stress-free environment will help prevent the disease’s symptoms from showing.

Pro tip: Mix in some catnip into your cat’s food bowl to get your kitty in a relaxed and playful mood.

Additionally, there are medications that are proven to help some cats with FHV-1. Anti-viral drugs like AZT have shown to decrease the blood concentration of the virus; as well as reducing the symptoms to a minimum. Study results do vary in this case as well though; so it is best to consult your veterinarian about these medications.

Conclusion And Further Reading

Although there are a number of studies surrounding L-Lysine and its use for cats; it’s still not 100% clear as to whether it is beneficial in treating FHV-1 or other diseases. However, the majority of new and comprehensive studies strongly suggest that the compound is not helping cats with infections.

Looking back, it is crazy to think that over 90% of veterinarians prescribed L-Lysine even though it did not show scientific proof of helping kitties with FHV. After all, we want to make sure our cats live a strong, happy and healthy life!

As time passes, more studies will surely be conducted to find out the absolute truth about L-Lysine. For now, based on the research that has been done so far, it is not advisable to supplement your cat’s diet with L-Lysine. There are other, better options available to get your kitty back to health.

If you would like to expand your knowledge regarding your kitty’s health, stick around! There are plenty of informative articles in this blog that inform you about keeping your cat strong, happy and healthy.

Author Bio:

Maria is a proud cat mom for 5 years now and loves to write about anything related to cats. She is currently working for KittySensations, a company that designs and sells handmade cat jewelry to cat moms across the globe. The company is dedicated to bringing cat lovers across the globe joy and happiness with their unique feline bracelets, earrings, necklaces and more.

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3 replies
  1. Nancy Moisan
    Nancy Moisan says:

    My Persian has respiratory problems and can be triggered by stress. He has an extremely “smushed” nose, he is a rescue so dont know history. He required antibiotic and L-lysine which i stopped when he seemed back to normal, now after more antibiotic, recommended he be on the L-lysine for life! He’s getting it twice a day, HCI oral paste formula, called Enisyl-F. He does improve considerably and to date, antibiotic maybe once a year, i was told some cats require it at least once a month which to me defeats the purpose when immune system is low. I will look into catnip, he has totally gone off canned food which i was giving him twice a day along with his dry food that is constant. Maybe mixing a bit in canned food will entice him, adds more moisture to his diet. Thanks, will forward this article to my veterarian, Nancy Moisan

  2. Jodie Novello
    Jodie Novello says:

    Hi. My cat had runny eyes for months when we first rescued her. Vet said prob herpes virus. At the time I researched it and lysine was recommended. At that time you couldn’t give human lysine from chemist because it had preservative in it toxic to cats and only one company was making for cat. Viralys. I bought it from overseas( I’m in Australia) and I swear, after about a week her eye stopped running. A year later she got a cold/ cat flu and couldn’t breathe well, I supplemented with the lysine and she got better and had never had another episode even when she was a bit run down with a bladder infection last year. Now my other cat has flu , first time for her and I’m doing everything I did with other cat except the lysine because I’m waiting for it to arrive. It’s been nearly two weeks, been to vet, on antibiotics, not getting any better. So I’m going to give her the lysine. I don’t think it can hurt them if it’s just when they are sick. I know this is only personal experience and not scientific but I believe it does work. It can’t be placebo in a cat. Just sayin 😊

  3. Ray
    Ray says:

    Thanks Jodie. It’s too bad that purchasing lysine is somewhat restricted in Australia. Luckily you were able to procure it and give to your cat!


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