Feline Herpes Virus: Bad News for a Popular Treatment - petMD

Immune System Support is safe and effective nutritional supplement for cats responsive to Lysine.
There are a lot of different Lysines on the market, but the one I give to Lily (and all of my cats) is called Vetoquinol Viralys Powder. As I said above, I started giving it to her within a month or two of her being diagnosed with stomatitis. It helped, though I admit that it wasn’t enough to “cure” the inflammation in her mouth. But, it did help lessen the pain and redness.
Lysine-Aid For Cats for the management of feline herpes in kittens and cats.
Cat Lysine or L-Lysine for cats is used to treat upper respiratory problems or Not only can it improve their upper respiratory infection (URI) symptoms, but also inflammation of the eyes and caused by feline herpes. Lysine and L-lysine for Cats - Supplement Benefits, Dosage, Side EffectsCat Lysine and cat amino acid health | The Benefits of L-Lysine in Cats from thomas Labs.Vetoquinol Enisyl-F Lysine supplements are specifically developed for cats and kittens
Cat herpes, otherwise known as rhinotracheitis, is an upper respiratory illness that can also potentially affect the eyes. It is an airborne virus, and because of how easily cat herpes spreads, cats that live with other cats in the same household are the most at risk. While L-Lysine supplements are not a direct cure for cat herpes, it has been clinically shown to both decrease a cat's risk of contracting the rhinotracheitis virus, and slow the growth of the infection.Although some antiviral medications developed for humans infected with HSV-1 can be used safely in cats and are effective against FHV-1, no medications or vaccines reduce establishment of latency or frequency of viral reactivation.1 In addition, other human antiviral drugs are ineffective against FHV-1, toxic to cats, expensive, or cannot be administered for protracted periods. This has led to investigation of adjunctive antiviral therapies, such as l-lysine therapy, that are safe, effective, and inexpensive and can be given long term.While lysine is an herbal remedy readily available at natural foodstores, occasionally lysine supplements contain preservatives. Thepreservative "propylene glycol" is a dangerous compound for cats. Catswho have ingested propylene glycol have been shown to experience sideeffects such as blood reactions. Always choose all natural ingredientswhen selecting a brand of l-lysine supplement to treat feline herpesand cat conjunctivitis. In Vivo Research
Results of 2 independent in vivo studies have supported the clinical use of l-lysine in cats. In the first of these studies,4 8 FHV-1-naive cats were administered 500 mg of lysine Q 12 H PO beginning 6 hours before, and continuing for 3 weeks after experimental inoculation with FHV-1. Lysine-treated cats had significantly less severe conjunctivitis than cats that received placebo.Evidence of Efficacy
Originally, lysine was administered to FHV-1-infected cats on the basis of data in humans that supported its efficacy against HSV-1. It was assumed that the agent would be safe in cats. However, excessive lysine administration has been shown to competitively inhibit arginine absorption in some species. This could have devastating effects in cats because arginine is an essential amino acid in this species. In one study,2 a single meal of a complete amino acid diet without arginine produced fatal encephalo­pathy in some near-adult cats. Therefore, careful investigation of lysine's antiviral efficacy against FHV-1 and its safety in cats is warranted.Indications & Course of Treatment
On the basis of the in vitro and in vivo data described, l-lysine is now commercially available in veterinary formulations and is recommended by many veterinarians for cats infected with FHV-1. Unlike the protocol for HSV-1-infected humans, owners of cats receiving l-lysine for FHV-1 are not advised to restrict the cat's arginine intake. There are no published data on dose, frequency of administration, course of therapy, or timing of lysine administration relative to herpetic disease episodes in clinical patients; thus, information on these issues is anecdotal.