Bail was set at $500,000 each for Sebastiano Quagliata, 45, and Valbona Lucaj, 44. The couple were arrested Thursday.
Quagliata, whose lawyer said he is a union painter, was still wearing his work clothes.
The couple live in Metamora in a rural area about 60 miles north of Detroit. On July 23, Craig Sytsma, 46, died after he was mauled by two Cane Corsos, large Italian dogs bred to hunt boar.
Prosecutors charged Quagliata and Lucaj with murder, which could mean life sentences if they are convicted, and harboring an animal that caused death.
During the hearing, Lapeer County Prosecutor Michael Hodges said the couple might be living in the United States illegally. Quagliata's lawyer denied that.
"He has been a union painter for 20 years," Jason Malkiewicz said. "He has numerous ties to the community. He was arrested at 4:30 at his work; his wife turned herself in voluntarily last night."
The couple have three children, all born in the United States. Hodges said they are being cared for by relatives.
The Cane Corsos that killed Sytsma have reportedly been involved in other attacks. A hearing on putting the dogs down, scheduled for Friday afternoon, was canceled.