Gothe R
Berl Munch Tierarztl Wochenschr. 1989 Sep 1;102(9):293-7.
Demodex canis is a normal resident of the intact canine skin, being present in small numbers in virtually every dog. Most animals are only carriers of the mites and do not develop clinical symptoms, therefore, demodectic mange has already to be considered as a factorial disease. The modus operandi of transition of clinically inapparent colonization of the mites into a disease may be explained according to investigations so far published multifactorially and thereby essentially as consequences of primary or secondary immunodepression. A primary immunodepression is initially based most probably on a hereditary defect of T-cells and is subsequently reinforced by substances, which are presumably synthesized and liberated not only by mites but also by secondary bacterial agents. A secondary immunodepression operates as trigger mechanism of a clinical manifestation after corticosteroid or cytostatic therapy or in course of underlying diseases of potentially immunodepressive nature, i.e., malignant neoplasia, hepatopathies, hyperadrenocorticism and lymphosarcoma.
犬蠕形螨是健康犬皮肤的正常寄居者，几乎每只狗身上都有少量存在。大多数动物只是螨的携带者，不会出现临床症状，因此，蠕形螨病已被视为一种多因素疾病。根据目前已发表的研究，螨的临床隐匿性定植转变为疾病的作用方式可从多方面进行解释，其本质上主要是原发性或继发性免疫抑制的结果。原发性免疫抑制最初很可能基于T细胞的遗传性缺陷，随后会被一些物质增强，这些物质可能不仅由螨合成和释放，还由继发性细菌病原体合成和释放。继发性免疫抑制在皮质类固醇或细胞抑制疗法后，或在具有潜在免疫抑制性质的基础疾病（即恶性肿瘤、肝病、肾上腺皮质功能亢进和淋巴肉瘤）过程中，作为临床表现的触发机制发挥作用。
