NAVLE（北美执业兽医考题）Day 721

A middle-aged dog was recently diagnosed with hyperadrenocortism. The owner has questions regarding skin lesions on this animal. There are erythematous papules and raised firm lesions. A single skin scraping is negative for mites, but there is gritty material in the scraping. Which one of the following choices is the most likely diagnosis?
一只中年犬最近被诊断患有肾上腺皮质机能亢进。主人就这只动物的皮肤情况有些疑问。他的皮肤上出现了发红并且突起，摸上去较硬的斑疹。单次的皮肤刮片检查没看到螨虫，但是刮片中有沙砾。最可能的诊断是什么？