Dog skin diseases can be roughly divided into 5 types according to their causes. One is fungal skin diseases, which are mainly characterized by round patches of hair loss, itching, etc.; the other is bacterial skin diseases, which mostly cause skin ulcers and Purulence, and the cortex is significantly increased; the third is parasitic skin diseases, usually redness, itching and dandruff caused by flea and mite bites; the fourth is allergic skin diseases, which usually occur more frequently in spring, mainly due to special allergen dust , pollen, etc., the most obvious one is persistent itching. The fifth is endocrine dermatoses, most of which are caused by other internal diseases such as adrenal insufficiency.