Effects of dietary lysine supplementation on upper respiratory and ocular disease and detection of infectious organisms in cats within an animal shelter.
OBJECTIVE
To determine within a cat shelter effects of dietary lysine supplementation on nasal and ocular disease and detection of nucleic acids of Chlamydophila felis, feline calicivirus (FCV), and feline herpesvirus (FHV-1).


METHODS
261 adult cats.


METHODS
Cats were fed a diet containing 1.7% (basal diet; control cats) or 5.7% (supplemented diet; treated cats) lysine for 4 weeks. Plasma concentrations of lysine and arginine were assessed at the beginning (baseline) and end of the study. Three times a week, cats were assigned a clinical score based on evidence of nasal and ocular disease. Conjunctival and oropharyngeal swab specimens were tested for FHV-1, FCV, and C felis nucleic acids once a week.


RESULTS
Data were collected from 123, 74, 59, and 47 cats during study weeks 1, 2, 3, and 4, respectively. By study end, plasma lysine concentration in treated cats was greater than that in control cats and had increased from baseline. There was no difference between dietary groups in the proportion of cats developing mild disease. However, more treated cats than control cats developed moderate to severe disease during week 4. During week 2, FHV-1 DNA was detected more commonly in swab specimens from treated versus control cats.


CONCLUSIONS
Dietary lysine supplementation in the amount used in our study was not a successful means of controlling infectious upper respiratory disease within a cat shelter. Rather, it led to increases in disease severity and the incidence of detection of FHV-1 DNA in oropharyngeal or conjunctival mucosal swab specimens at certain time points.
Drazenovich
Tracy L
TL
Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
Fascetti
Andrea J
AJ
Westermeyer
Hans D
HD
Sykes
Jane E
JE
Bannasch
Mike J
MJ
Kass
Philip H
PH
Hurley
Kate F
KF
Maggs
David J
DJ
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D017927:Calicivirus, Feline / Q000302:isolation & purification; D002371:Cat Diseases / Q000382:microbiology / Q000517:prevention & control*; D002415:Cats; D023521:Chlamydophila Infections / Q000517:prevention & control / Q000662:veterinary; D019587:Dietary Supplements; D015817:Eye Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D006564:Herpesviridae / Q000145:classification; D006566:Herpesviridae Infections / Q000662:veterinary*; D008239:Lysine / Q000494:pharmacology*; D008297:Male; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*
D008239:Lysine