Prevalence of Demodex infection in pet dogs in Southern China

Canine demodicosis caused by ectoparasitic mites in the genus Demodex is a major and common ectoparasitic disease of dogs. However, little is known of the prevalence of Demodex infection in pet dogs in China. The present study was conducted to determine the prevalence of Demodex infection in pet dogs in Guangzhou, Southern China. A total of 3977 pet dogs admitted to several animal hospitals in Guangzhou City were investigated for Demodex infection from January to December 2009. The result showed that 977 (24.57%) dogs were positive for dermatosis and 130 (13.31%) of the dermopathic dogs were positive for Demodex infection. No significant association was found between Demodex prevalence and season, age, and gender of pet dogs. Seasonal prevalence showed that the highest and lowest were in March (4.15%) and December (1.39%), respectively. The prevalence in male dogs (3.67%) was higher than that in female dogs (2.74%). Dogs of 1 to 5 year old were more commonly infected than other age groups. The present investigation revealed the prevalence of Demodex infection in pet dogs in China’s subtropical Guangzhou City, which accounts for 13.31% of canine dermatosis cases. These results have important implications for conducting control strategies and measures against canine demodicosis in this region.