Density measurement of Demodex canis by qPCR and analysis of serum cytokine levels in dogs with different clinical forms of demodicosis.
OBJECTIVES To quantify (by qPCR) the density of Demodex canis mites in the skin of dogs with demodicosis and in healthy dogs, as well as measuring the serum concentrations of interleukin (IL) 1b, IL 6, IL 8, IL 10, IL 12, and tumour necrosis factor alfa (TNF a) METHODS Fifty four dogs were divided into three groups: localized demodicosis (LD, n 16) generalized demodicosis (GD, n 22) and control group (CG, n 16) All dogs were subjected to skin scraping, blood collection, and skin biopsy. DNA extraction was performed and the parasite density was established by qPCR. Serum cytokine concentrations were obtained by flow cytometry. RESULTS The median number of mites in the skin of the GD (6.2 x 104 copies/mL) and LD dogs (1.2 x 104 copies/mL) was statistically higher than that in the CG dogs (8.7 x 102 copies/mL) Whereas there were no significant differences in median IL 1b, IL 8, IL 10, IL 12, and TNF a levels among the study groups, there was a statistically higher IL 6 concentration in the LD dogs than in the healthy dogs. CONCLUSIONS According to our results, qPCR is an effective method for measuring the density of D. canis in the canine integument. In addition, the activation of the acute phase immune response in localized demodicosis can be induced by IL 6 activity.
Veterinary parasitology