The Dog Mite, Demodex canis: Prevalence, Fungal Co-Infection, Reactions to Light, and Hair Follicle Apoptosis

• Published in: Journal of insect science (Tucson, Ariz.) Ariz.), 2011, Vol.11 (76), p.1-13
• Main Authors: Tsai, Yu-Jen, Chung, Wen-Cheng, Wang, Lian-Chen, Ju, Yu-Ten, Hong, Chin-Lin, Tsai, Yu-Yang, Li, Yi-Hung, Wu, Ying-Ling
• Format: Article
• Language: English
• Subjects: Age; Animals; Apoptosis; Canis; Comorbidity; Demodex canis; Dermatomycoses - epidemiology; Dermatomycoses - microbiology; Dog Diseases - epidemiology; Dog Diseases - microbiology; Dog Diseases - parasitology; Dogs; Eosinophils; Female; Follicles; fungi; Hair; Hair Follicle - pathology; Health aspects; Host-Parasite Interactions; Infection; Landscape; Leukocyte Count; Light; Light effects; Male; map overlay; Microsporum - isolation & purification; Microsporum canis; Mite Infestations - epidemiology; Mite Infestations - microbiology; Mite Infestations - pathology; Mite Infestations - veterinary; Mites; Mites - physiology; Physiological aspects; Prevalence; Prevalence studies (Epidemiology); Prostigmata; Sex; Skin; Taiwan; Taiwan - epidemiology; Trichophyton - isolation & purification; Trichophyton mentagrophytes
• ISSN: 1536-2442; 1536-2442
• DOI: 10.1673/031.011.7601

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.