He was killed in a purge of high-level Tang officials by the warlord Zhu Quanzhong the military governor (Jiedushi) of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan), who was then preparing to seize the throne.
Soon thereafter, in spring 904, the powerful warlord Zhu Quanzhong the military governor of Xuanwu Circuit, whose troops had the imperial Chang'an under control, accused the leading chancellor Cui Yin of crimes and had Cui killed, and then had his troops forcibly move then-reigning Emperor Zhaozong, the imperial officials, and the residents of Chang'an to Luoyang, to make Luoyang the new capital.
At that time, Dugu and the other chancellors Pei Shu and Cui Yuan all were senior officials who came from aristocratic families, and they despised their colleague Liu Can for associating with Zhu.
Zhu thus had all three removed from chancellor positions; in Dugu's case, he was made the military governor of the remote Jinghai Circuit (靜海, headquartered in modern Hanoi, Vietnam).
Soon thereafter, some 30 of these officials—including Dugu, Cui, Pei, fellow former chancellors Lu Yi, Wang Pu, and other officials Zhao Chong (趙崇) and Wang Zan (王贊)—were rounded up at Baima Station (白馬驛, in modern Anyang, Henan) and ordered to commit suicide.