Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus.
OBJECTIVE
To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats.


METHODS
14 young adult, FHV-1-naive cats.


METHODS
Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30.


RESULTS
Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroid-induced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered.


CONCLUSIONS
Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects.
Maggs
David J
DJ
Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
Nasisse
Mark P
MP
Kass
Philip H
PH
D000284:Administration, Oral; D000818:Animals; D001120:Arginine / Q000097:blood; D002371:Cat Diseases / Q000378:metabolism / Q000821:virology*; D002415:Cats; D003231:Conjunctivitis / Q000188:drug therapy / Q000662:veterinary / Q000821:virology; D019587:Dietary Supplements / Q000592:standards; D005938:Glucocorticoids / Q000494:pharmacology; D006564:Herpesviridae / Q000502:physiology*; D006566:Herpesviridae Infections / Q000188:drug therapy / Q000662:veterinary* / Q000821:virology; D008239:Lysine / Q000097:blood / Q000494:pharmacology*; D008775:Methylprednisolone / Q000494:pharmacology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012367:RNA, Viral / Q000032:analysis; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D014775:Virus Activation; D017201:Virus Shedding / Q000187:drug effects
D005938:Glucocorticoids; D012367:RNA, Viral; D001120:Arginine; D008239:Lysine; D008775:Methylprednisolone