Alice Cooper has revealed Joe Perry hadn't eaten for two days before his collapse on stage in Brooklyn last month.

The Hollywood Vampires

The Hollywood Vampires

The 'Poison' hitmaker has said he thinks the Hollywood Vampires heavy tour schedule "caught up" with the 65-year-old guitarist and lack of sleep and not having regular meals all contributed to him passing out due to dehydration and exhaustion at the Ford Amphitheater on July 10.

The 68-year-old rocker said: "We were doing 25 to 30 songs with no break," he continues. You're in fourth gear, and there's no 24-hour resting period. I think it just caught up with him. He finally got up there onstage, dehydrated. And I think he was exhausted. He told me the night before he hadn't eaten in two days."

Asked why he didn't eat, he added: "I said, 'Man, you've got to know when to sleep. You've got to know when to eat on a tour.'

"I think it just finally got to him. It was not a heart attack; it was pure exhaustion. They checked his heart and said his heart was actually very strong."

Meanwhile, Cooper - who is also joined by Johnny Depp, Matt Sorum from Guns N' Roses and Robert DeLeo from Stone Temple Pilots in the group - said seeing his bandmate collapse "scared the hell of [him]" because they didn't realise what had happened until they finished the show.

Referring to their track 'Raise the Dead', he told Rolling Stone magazine: "It scared the hell out of me. The lyrics to ['Raise the Dead'], the first song we played that night, go, 'Cardiac, heart attack ... they never feared the reaper,' and I look around the stage and he's gone. He was lying behind an amp on his back, and I went, 'Oh, my God.' We didn't know what happened until after the show."

Meanwhile, Perry's Aerosmith bandmate Steven Tyler expressed his concern that the group had been over-booked, leading to the six string strummer's health issues.

He previously said: "I think he's out there and someone's over-booking him. Even though one could say the band booked themselves; well, that's righteous of 'em, but they're doing like eight or nine shows in a row - or five in a row. And I think they're all a little burnt. I think they need to look at that, Y'know, not young anymore, right?"