Army Spc. Kevin Shumaker, 24, died from rabies last month. His death came eight months after he was bit by a dog at a remote Afghanistan military base.
His parents spoke to the Bay Area News Group and say they want to know why their son died of a preventable disease. His mother Elaine Taylor told the paper, "I would not be without my son if the proper treatment was given to Kevin."
Shumaker told his parents he was only given three in the series of shots because the rest had expired.
Following his death, the Army says it has formed a rabies response team to protect other troops.