The dog mite, Demodex canis: Prevalence, fungal co-infection, reactions to light, and hair follicle apoptosis

Yu-Jen Tsai1, 7a, Wen-Cheng Chung2b, Lian-Chen Wang3c, Yu-Ten Ju4d, Chin-Lin Hong5e, Yu-Yang Tsai6f, Yi-Hung Li7g, and Ying-Ling Wu7h*

1Taipei City Animal Protection Office, No.109, Ln. 600, Wu-Xin Street, Taipei 11048, Taiwan
2Department of Parasitology, Taipei Medical University, No. 250, Wu-Xin Street,Taipei 11042, Taiwan
3Graduate Institute of Biomedical Sciences, Chang Gung University, College of Medicine, 259 Wen-Hwa 1st Road, Kwei-Shan Tao-Yuan 33302, Taiwan
4Department of Animal Science and Technology, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
5Department of Public Health, Taipei Medical University, No. 250, Wu-Xin Street, Taipei 11042, Taiwan
6Land Environmental Information Consulting Association, 20F-1, No.6 Bau Ching St. Hsing-dian, Taipei 23143, Taiwan
7School of Veterinary Medicine National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan

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.

Keywords: fungi, map overlay, Taiwan

Correspondence: a tcapo019@mail.taipei.gov.tw, b wcchung@tmu.edu.tw, c csp@mail.cgu.edu.tw, d ytju@ntu.edu.tw, e hongcl@tmu.edu.tw, f leigis@msn.com, g r91626006@ntu.edu.tw, h* wuyl@ntu.edu.tw, *Corresponding author

Editor: T.X. Liu was editor of this paper

Received: 19 May 2010 | Accepted: 10 October 2010 | Published: 29 June 2011

ISSN: 1536-2442 | Volume 11, Number 76

Tsai Y-J, Chung W-C, Wang L-C, Ju Y-T, Hong C-L, Tsai Y-Y, Li Y-H, Wu Y-L. 2011. The dog mite, Demodex canis: Prevalence, fungal co-infection, reactions to light, and hair follicle apoptosis. Journal of Insect Science 11:76 available online: insectscience.org/11.76


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