肉眼检查通常局限于症状比较明显的鱼病和大型寄生虫病，而对一些症状不太明显和小型寄生虫引起的鱼病则需要经显微镜检查，同时由于鱼病发病情况比较复杂，存在多种并发症要正确诊断，单凭肉眼不能确定病症，需要更准确地确定出病原体的种类时，必须用显微镜做详细检查。 镜检 Macroscopic examination is usually confined to the more obvious symptoms of fish disease and large parasitic disease, and some symptoms are not obvious and small parasitic fish disease caused by the need for microscopic examination, and due to the incidence of fish disease is more complicated, there are many Complications to the correct diagnosis, the naked eye can not determine the disease, the need to more accurately determine the type of pathogen, you must use a microscope for detailed examination. Microscopic examination