"Mindy really loved her dog and that would not have been an act of malice at all," Fox News quoted the unidentified friend as saying. "It would have been more of a case where she just didn't want to leave the dog alone."
McCready, 37, fatally shot her dog, then herself Sunday afternoon.
The faded country music star had battled addictions to drugs and alcohol for years. Her two young sons were placed in foster care this month because, her family said, she wasn't taking care of them after her fiance's January death.
A memorial is being planned for McCready in Nashville, Fox News said.
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