Feral and domestic felines are continuously exposed to meso- (polymer length: 5–25 mm) and microplastics (polymer length < 5 mm) from environmental or household contaminants. Ingestion and inhalation are the primary pathways for internalization of plastic, non-plastic anthropogenic (e.g., rayon, AP), and natural cellulose particles. However, contamination information is limited for companion animals. This study focused on reproductive tissue of felines by obtaining samples from spay (ovary + uterus) and neuter (testes) procedures. The tissue was chemically digested and then analyzed via microscopy and Fourier-Transform Infrared Spectroscopy (FTIR) to detect and identify contamination. Overall, 71% of 100 individuals contained particles (meso- and microplastics, non-plastic anthropogenic particles, cellulose), of which 97.3% were fibers. Foreign particles were present in the uterus and ovaries of 100% of domestic females, while only 36% of feral males had particles in their testes. Overall, 25% of the FTIR-confirmed particles were plastic, 54% were AP, and 21% were cellulose. The most common plastic found was polyethylene terephthalate (PET), a common polymer used in packaging food and beverages, including manufactured cat food and bottled water. This study provides a baseline for understanding plastic and AP concentrations in the reproductive tissues of both feral and domestic felines.