Evaluation of Lysine and Lysine-Lactoferrin Association in Cats Infected by Feline Herpesvirus-1

Feline Herpesvirus type 1 (FHV-1), the causative agent of feline infectious rhinotracheitis is a high widespread virus. At the present, treatment is aspecific and symptomatic, often based on collateral antibiotic treatment. The antiviral effect of lysine, an essential basic amino acid has been widely investigated and is related to a competitive inhibition against arginine. Lactoferrin is a glycoprotein of the transferrin family that seems able to prevent the internalization process and to inhibit viruses replication within the host cells. The aim of the present study was to verify the efficacy of lysine alone and of the association lysine-lactoferrin against FHV-1 in cats. For this purpose, four groups of five FHV-1 infected cats each were treated with different products and monitored at different time points clinically and virologically. In particular, patients received the association lysine-lactoferrin per os (group 1), the association lysine-lactoferrin via aerosol (group 2), only lysine per os (group 3) and the association amoxicillin-clavulanic acid (group 4). Four patients of group 1 (80%), 3 of group 2 (60%), 3 of group 3 (60%) and 5 of group 4 (100%), clinically improved till a complete remission of systemic condition and respiratory symptoms. Viral shedding in oculo-conjunctival samples gradually decreased in almost all cats. These data suggest that the association lysine-lactoferrin could be a first choice in FHV-1 infected cats for reducing clinical signs and viral shedding. Antibiotics should be used only when non-antibiotic products are not sufficient in limiting the secondary bacterial infections.