According to the sheriff's office, the hunter was shot in the passenger seat on a country road about 74 km (46 miles) south of Wichita.
The dog was seated in the backseat with all the hunting gear and next to the rifle.
Fortunately, the other person, who was driving the truck, was not hurt in the incident.
Within minutes, emergency services arrived and performed CPR, but the 30-year-old later died at the scene.
"A canine belonging to the owner of the pickup stepped on the rifle, causing the weapon to discharge," deputies said, as per UPI.
"The fire round struck the passenger, who died of his injuries on scene."
Jimmy White, claiming to be a friend of Smith’s wrote in the comments on KAKE News’ Facebook post: “To all the comedians and weapons experts here: This boy was my friend, having been best friends for over 20+ years with his dad.
“These comments are hateful. I know this family very well and cannot tell you how much their hearts hurt right now. Shame on you.”
Similarly, in Turkey last year, a man was fatally injured after his pooch stepped on the trigger of his gun.
Ozgur Gevrekoglu, 32, was killed while hunting with his friend in the Kızlan Plateau in the Samsun Province of Turkey in November, the newspaper Turkiye reported, as per the New York Post.
The incident occurred as Gevrekoglu was organising his hunting kit in the back of the vehicle.
The dog then touched the loaded weapon, which fired at his owner from a near distance.
Gevrekoglu suffered a gunshot wound to the stomach and was then transported to Alaçam State Hospital, but he was pronounced dead upon arrival.
According to the outlet, the man became a father two weeks before and was a dog lover and an avid hunter.
He frequently posted pictures of hounds and dead birds on his social media.