Abstract
Background:
Chlamydia are obligate generally Gram-negative intracellular parasites with bacterial characteristics, including a cell wall, DNA, and RNA, the main characteristics of infections are ocular conjunctivitis and upper respiratory disease.

Aim:
The aim of this study was to investigate the prevalence of Chlamydophila infection in a population of shelter cats in Baghdad city.

Methods:
Molecular detection was done using a PCR approach. 50 shelter cats of various ages, sexes, and breeds participated in the study from 1/11/2023 to 1/4/2024. DNA was extracted and amplified using PCR.

Results:
The study's findings revealed the PCR technique showed that 22/44%positive cats from a total of 50 cats was assured for the 23S rRNA gene and yielded a band at 400bp, 41/27.3% these findings are regarded as distinctive for the genus Chlamydophila and positive sample 30/20% from a total of 150 samples was assured for Chlamydophila felis, a band at 680 bp. The findings revealed that the prevalence of Chlamydophila in upper respiratory tract infections in female cats older than one year was between 14/50(28%) and 13/50(26%) conversely, the infections exhibited greater prevalence and a higher rate of detection in male under one year of age. The present investigation highlighted a significant prevalence of Chlamydophila in respiratory swabs obtained from Persian and Himalayan cats, but Scottish and British cats exhibited a comparatively lower rate of positive Chlamydophila.

Conclusion:
In conclusion of this study, that a significant number of cats are infected with Chlamydophila felis, PCR provided rapid and sensitive detection of Chlamydophila species in different samples and detected Chlamydophila that didn't grow in culture. It was considered the first study for the detection of Chlamydophila felis from conjunctivitis in shelter cats in Baghdad city.

Key words: Co-infection, Feline chlamydophilasis, PCR, Shelter cats, URTI