Xiaojuan Zhu

Objective To survey the prevalence of pathogens in shelter‐housed cats with active ocular surface disease (OSD). Animals Studied A total of 255 shelter‐housed domestic cats with evidence of active OSD. No normal, unaffected cats were sampled. Procedure(s) OSD scoring was performed on cats with active OSD. Combined oropharyngeal/conjunctival swabs were submitted for rt‐PCR/PCR for feline herpesvirus (FHV‐1), feline calicivirus (FCV), Chlamydia spp. (CHL), Bordetella bronchiseptica (BORD), and Mycoplasma spp. (MYC). Results Pathogens were detected as follows: 76.4% (195/255) MYC, 57.6% (147/255) FHV‐1, 42.7% (109/255) FCV, 26.7% (68/255) CHL, and 5.5% (14/255) BORD. Monoinfections affected 21.1% (54/255) animals, with MYC being the most common monoinfection (12.5%, 32/255), followed by FHV‐1 (4.7%, 12/255), followed by CHL (2.4%, 6/255), followed by FCV (1.6%, 4/255), with no animals having a BORD monoinfection. Dual infections affected 36.4% of animals (93/255), with MYC detected in 30.1% (77/255) dual infections and FCV detected in 12.9% (33/255) dual infections. Dual infections with MYC and FCV together were detected in 9.8% (25/255) animals. Many animals (35.3%, 90/255) were found to be affected by 3 or more pathogens, and 7.1% (18/255) animals had no pathogens detected. OSD scores were not influenced by any variable assessed, including the number and type of pathogens detected. Conclusion MYC, FHV‐1, FCV, and CHL were commonly detected in this group of animals with OSD. Both MYC and FCV (alone or in combination with each other) were detected in multiple animals with active OSD, supporting prior evidence that either may independently act as a primary ocular surface pathogen.