Feline Herpesvirus – What Is the Role of Lysine Supplementation?

FELINE HERPESVIRUS Despite the ready availability of vaccines and antiviral drugs effective against feline herpesvirus type 1 (FHV-1), this virus remains a major, common, and frustrating pathogen of cats worldwide. FHV-1 has been associated with acute, chronic, and recurrent conjunctivitis, ulcerative and stromal keratitis, corneal sequestrum, eosinophilic keratitis, anterior uveitis, dermatitis, and rhinosinusitis. Classically, primary infection with FHV-1 in susceptible kittens is associated with acute upper respiratory and ocular disease with approximately 100% morbidity, particularly in multi-cat environments. Following primary exposure, FHV-1 establishes lifelong neural latency with periodic reactivation in approximately 80% of cats. A small but clinically important subset of carrier cats experiences chronic recurrent herpetic disease. Currently, no medications or vaccines have been demonstrated to reduce establishment of latency or frequency of viral reactivation. In addition, some 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 that are safer, effective, less expensive, and can be given more chronically. The amino acid, L-lysine, is such a therapy.