Burden of Common Respiratory Pathogens Among Cats in China

Feline respiratory disease complex (FRDC) is a set of illnesses which are primarily associated with different types of viruses and bacteria. There is scarcity of data on pathogens associated with FRDC in China.

The primary objective of this study was to investigate the prevalence and dynamics of FRDC pathogens in China.

A total of 458 samples were retrieved from veterinary clinics during 2021-2024 from cats suffering from respiratory infections. Four viruses and three bacteria associated with FRDC were targeted for molecular detection with real time qPCR/RT-qPCR assays.

At least 1 targeted respiratory pathogen was detected in 423 samples (92.3%), whereas no pathogens were detected in 7.7% of samples. Bacteria were detected in 32.1% of samples, and viruses were detected in 60.2% of samples. The prevalence of viruses detected were feline calicivirus (31.2%), feline herpesvirus-1 (24.6%), influenza A virus (2.8%) and severe acute respiratory syndrome coronavirus-2 (1.5%), whereas the detection rate for bacteria was Mycoplasma felis (15.5%), Chlamydia felis (10.2%) and Bordetella bronchiseptica (6.3%). Significantly higher cases were reported from kittens (57.4%). Pathogen detection was more common during the cold season. Mono-infections involving one bacteria or virus were detected in 44.7% of samples, whereas coinfections were detected in 47.5% of samples. No quadruple coinfections were recorded in this study.

The frequency of detection of feline respiratory pathogens alone or in combinations among diseased cats was high, indicating a heavy burden of respiratory infections among cats in Kunshan, China. Continued surveillance is desired, and newly emerged respiratory pathogens should also be monitored in routine diagnostic testing.