Histopathology and Intensity of Demodex Mite Invasion in an Immunosuppressed Dog Using a Clinical Case Example

Introduction. Demodicosis in adult dogs often develops against a background of immunosuppression, and diagnosis can be challenging when scrapings yield negative results. The literature lacks sufficient data on morphometric assessment of invasion intensity.

Clinical Case Description. Histological analysis of two skin biopsies from a Central Asian Shepherd dog, taken 24 days apart, was performed with morphometry and mite counting per unit area. The first biopsy revealed single Demodex mites (3 individuals per 5±0.2 mm²), moderate dermatitis and folliculitis. Twenty-four days later, during glucocorticoid therapy, the second biopsy showed a sharp increase in mite numbers to 339–452 individuals per the same area, along with ulcerative dermatitis and granulomatous inflammation.

Discussion. The use of systemic and topical glucocorticosteroids in a dog with initially low invasion intensity led to a dramatic increase in mite population and aggravation of histopathological skin changes. This case confirms that generalized demodicosis in adult dogs is a marker of an immunosuppressive state, and prescribing glucocorticoids without antiparasitic therapy is strictly inadmissible. Negative results from superficial scrapings do not rule out demodicosis, especially in dogs with thickened skin or chronic lesions.

Conclusion. Histological examination of the skin is mandatory when scrapings are negative and clinical signs of demodicosis in adult dogs are pronounced. Glucocorticoids should not be prescribed before biopsy results are available.

1. Petrova OY, Bardakhchieva LV. Diagnostics and treatment of generalized demodicosis in dogs. Journal of Agriculture and Environment. 2025;(1)53:1–8. https://doi.org/10.60797/JAE.2025.53.5

2. Sousa VRF, Gasparetto ND, Almeida ABPF. Clinical and immuno-pathology aspects of canine demodicosis. In: Veterinary Medicine and Science. London: IntechOpen; 2019. https://doi.org/10.5772/intechopen.88763

3. Акбаев Р.М., Богданова А.В., Колпаков И.Д. Клещи–паразиты домашних плотоядных животных. Дневник науки. 2022;(5(65)).

4. Putra MAR, Sajuthi CK. Hyperadrenocorticism Induces Demodicosis in Shih Tzu Dog. ARSHI Veterinary Letters. 2017;1(1):7–8. https://doi.org/10.29244/avl.1.1.7-8

5. Piter RL. Randomized, blind clinical trial of the efficacy and safety of oclacitinib and cyclosporine for the treatment of atopic dermatitis in domestic dogs. VetPharma. 2016;32 (4):28–38.

6. Sood NK, Mekkib B, Singla LD, Gupta K. Cytopathology of parasitic dermatitis in dogs. Journal of Parasitic Diseases. 2011;35(2):73–77. https://doi.org/10.1007/s12639-011-0083-y

7. Fouda A, Clinical, haemato-biochemical, and histopathological studies on some dermopathies in dogs. Advances in Animaland and Veterinary Sciences. 2021;9(1):94–102. https://doi.org/10.17582/journal.aavs/2021/9.1.94.102

8. Thakur M. Hriyadesh Prasad, Arya RS, Singh YD., Jayappa Kiran, Abhijit Deka, Kalyan Sarma, et al. Histopathological changes in canine demodicosis. International Journal of Current Microbiology and Applied Sciences. 2019;8(3):2176–2179.