title: The dog mite, Demodex canis: prevalence, fungal co-infection, reactions to light, and hair follicle apoptosis.
abstract: Infection rate, reaction to light, and hair follicle apoptosis are examined in the dogmite, Demodex canis Leydig (Prostigmata: Demodicidae), in dogs from the northern area of Taiwan. An analysis of relevant samples revealed 7.2% (73/1013) prevalence of D. canis infection. Infection during the investigation peaked each winter, with an average prevalence of 12.5% (32/255). The infection rates significantly varied in accordance with month, sex, age, and breed (p < 0.05). Most of the lesions were discovered on the backs of the infected animals, where the infection rate was 52.1% (38/73) (P < 0.05). The epidemiologic analysis of infection based on landscape area factor, found that employing a map-overlapping method showed a higher infection rate in the eastern distribution of Taiwan's northern area than other areas. Isolation tests for Microsporum canis Bodin (Onygenales: Arthrodermataceae) and Trichophyton mentagrophyte Robin (Blanchard) on the D. canis infected dogs revealed prevalence rates of 4.4% (2/45) and 2.2% (1/45), respectively. Observations demonstrated that D. canis slowly moved from a light area to a dark area. Skin samples were examined for cellular apoptosis by activated caspase3 immunohistochemical staining. Cells that surrounded the infected hair follicles were activated caspase3-positive, revealing cell apoptosis in infected follicles via the activation of caspase3.
authors.affiliation: Taipei City Animal Protection Office, No. 109, Ln. 600, Wu-Xin Street, Taipei 11048, Taiwan. tcapo019@mail.taipei.gov.tw
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Tsai
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Chung
authors.forename: Lian-Chen
authors.initials: LC
authors.lastname: Wang
authors.forename: Yu-Ten
authors.initials: YT
authors.lastname: Ju
authors.forename: Chin-Lin
authors.initials: CL
authors.lastname: Hong
authors.forename: Yu-Yang
authors.initials: YY
authors.lastname: Tsai
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Li
authors.forename: Ying-Ling
authors.initials: YL
authors.lastname: Wu
mesh_terms: D000818:Animals; D017209:Apoptosis; D015897:Comorbidity; D003881:Dermatomycoses / Q000453:epidemiology / Q000382:microbiology*; D004283:Dog Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000469:parasitology; D004285:Dogs; D004804:Eosinophils; D005260:Female; D018859:Hair Follicle / Q000473:pathology; D006790:Host-Parasite Interactions; D007958:Leukocyte Count; D008027:Light; D008297:Male; D008864:Microsporum / Q000302:isolation & purification; D008924:Mite Infestations / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D008925:Mites / Q000502:physiology*; D015995:Prevalence; D013624:Taiwan / Q000453:epidemiology; D014249:Trichophyton / Q000302:isolation & purification