Retrospective survey of parasitism identified in feces of client-owned cats in North America from 2007 through 2018.

Ownership of domestic cats in North America has been on the increase; however, there are only a few surveys conducted on the prevalence of parasitism in client-owned cats over years. Our study objective was to evaluate parasite prevalence through statistical analysis of fecal examination results for client-owned cats on samples submitted to the veterinary parasitology diagnostic laboratory of Oklahoma State University over a 12-year period. All results of centrifugal flotation, saline direct smear, sedimentation, and Baermann examinations on fecal samples submitted to the Boren Veterinary Medical Hospital and Oklahoma Animal Disease Diagnostic Laboratory of Oklahoma State University from 2007 through 2018 were included. The impacts of sex, age, and seasonality on the prevalence of infection were also analyzed. A total of 2586 client-owned cat cases were included for this study. Parasites, eggs, oocysts, larvae, or cysts were not detected in the majority of cases (75.5%; 1,953/2586). Approximately 18.8% (485/2586) of client-owned cats were infected by one parasite, and 5.7% (148/2586) of cats were infected by multiple parasites. The most common parasite stage observed was Cystoisospora oocysts (9.4%; 243/2586), followed by Toxocara cati eggs (7.8%; 202/2586), Giardia cysts (4.0%; 104/2586), Alaria eggs (3.5%; 91/2586), Ancylostoma eggs (1.2%; 32/2586), taeniid proglottids/eggs (1.2%; 30/2586), Dipylidium caninum proglottids/egg packets (1.1 %; 29/2586), and Eucoleus aerophilus eggs (0.7%; 18/2586). Less commonly, Physalopetra eggs (0.19%; 5/2586), Toxascaris leonina eggs (0.19%; 5/2586), Tritrichomonas blagburni trophozoites (0.15%; 4/2586), Ollulanus tricuspis larvae/adults (0.12%; 3/2586), Platynosomum fastosum eggs (0.12%; 3/2586), Aelurostrongylus abstrusus larvae (0.08%; 2/2323), Sarcocystis sporocysts (0.08%; 2/2586), Spirometra eggs (0.08%; 2/2586), Mesocestoides proglottids/eggs (0.08%; 2/2586), Trichuris felis eggs (0.08%; 2/2586), Cryptosporidium oocysts (0.04%; 1/2586), and Toxoplasma-like small coccidian oocysts (0.04%; 1/2586) were detected. Additionally, fecal examinations revealed some ectoparasites: Demodex mites (0.9%; 24/2586), Cheyletiella mites (0.15%; 4/2586), and Otodectes cynotis mites (0.04%; 1/2586). There was no statistical significance between different sex groups (p = 0.3316). Age affected the prevalence of Cystoisospora, T. cati, Giardia, and Alaria infections with prevalence decreasing as age increased (p < 0.0001). Statistical analyses also revealed significant differences by months; the higher prevalence of infection occurred from summer through fall (p = 0.0004). Overall, as the number of submittals increased, the prevalence of infection increased over the last 12 years (p < 0.0001). This study supports continuing the current practice of routine broad-spectrum anthelmintic and ectoparasitic treatments for client-owned cats as well as annual/biannual fecal examination.