No other pathogens are known to cause these shoot symptoms. The symptoms can resemble herbicide injury, but Eutypa dieback does not cause shoot bunching, vein clearing or banding. Similar cankers can be caused by other fungi, and canker shape alone is not diagnostic for Eutypa dieback. Cankers have a definite margin between the live and dead wood. The cankers can be traced back to old pruning wounds by scraping the bark from the trunk or cordon.
Spurs bearing stunted shoots usually die the following year.
Cankered wood becomes distorted and twisted after a number of years. Spurs or cordons may be killed without the development of shoot symptoms. In this case, diagnosis depends on the presence of a canker and isolation of the pathogen. In areas of high rainfall or under sprinkler irrigation, vines older than ten years may develop perithecia on the dead xylem tissue of cankers. Perithecia are embedded in stromata of fungal and host tissue.