Correlation of Feline Coronavirus Shedding in Feces with Coronavirus Antibody Titer.
Felten SClinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, 80539 Munich, Germany.
Klein-Richers UClinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, 80539 Munich, Germany.
Hofmann-Lehmann RClinical Laboratory, Vetsuisse Faculty, Department of Clinical Diagnostics and Services, and Center for Clinical Studies, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
Bergmann MClinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, 80539 Munich, Germany.
Unterer SClinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, 80539 Munich, Germany.
Leutenegger CMIDEXX Laboratories, Inc., 2825 KOVR Dr., West Sacramento, CA 95605, USA.
Hartmann KClinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, 80539 Munich, Germany.
English
BACKGROUND Feline coronavirus (FCoV) infection is ubiquitous in multi-cat households. Responsible for the continuous presence are cats that are chronically shedding a high load of FCoV. The aim of the study was to determine a possible correlation between FCoV antibody titer and frequency and load of fecal FCoV shedding in cats from catteries.
METHODS Four fecal samples from each of 82 cats originating from 19 German catteries were examined for FCoV viral loads by quantitative reverse transcriptase polymerase chain reaction (RT-qPCR). Additionally, antibody titers were determined by an immunofluorescence assay.
RESULTS Cats with antibodies were more likely to be FCoV shedders than non-shedders, and there was a weak positive correlation between antibody titer and mean fecal virus load (Spearman r = 0.2984; p = 0.0072). Antibody titers were significantly higher if cats shed FCoV more frequently throughout the study period (p = 0.0063). When analyzing only FCoV shedders, cats that were RT-qPCR-positive in all four samples had significantly higher antibody titers (p = 0.0014) and significantly higher mean fecal virus loads (p = 0.0475) than cats that were RT-qPCR-positive in only one, two, or three samples.
CONCLUSIONS The cats' antibody titers correlate with the likelihood and frequency of FCoV shedding and fecal virus load. Chronic shedders have higher antibody titers and shed more virus. This knowledge is important for the management of FCoV infections in multi-cat environments, but the results indicate that antibody measurement cannot replace fecal RT-qPCR.