Corneal ulcers are frequently encountered in dogs. The purpose of this article is to describe the different types of ulcers by providing the data relating to etiology, pathogenis and physiology, so that the development of this disease may be understood. Subsequently, different therapies are suggested by specifying first of all the medical treatment, with a possible complementary surgical treatment. The surgical treatment implemented may invoice microsurgical techniques, if the practitioner is suitably equipped.