Canine Demodecosis

Demodex spp. mites are normally present as commensals in hair follicles and sebaceous glands in animals and humans, which multiply to excessive numbers causing clinical conditions. They have an elongated body with four stumpy legs, can be visualised under a microscope. Three species of demodectic mites are associated with disease in dogs. It is not contagious and is acquired from the dam during nursing. The most common species frequently encountered in dogs, Demodex canis, was first identified in 1859. Another causative agent is Demodex injai which has a longer body while D cornei has a short-body form, most likely to be a morphological variant of D canis (Mueller et al. 2020). There are various immunological, genetic, endocrine and other factors like breed, nutrition, length of hair, oxidative stress, debilitating diseases, that are risk factors and predisposing factors leading to rise in populations of mites associated with skin lesions like demodecosis. Various conditions like neoplasia, chemotherapy, hyperadrenocorticism or hyperthyroidism may lead to immunosuppression, triggering mite proliferation (Shchelkanov et al.,2020). The clinical presentation of demodecosis shows wide variation depending on the age at onset, the extent and severity of the lesions and the presence of secondary infection.