By Laura Zuckerman
SALMON, Idaho, March 21 (Reuters) - The mysterious disappearance of about 30 dogs in southern Idaho has baffled animal control officials and raised concerns among dog lovers after a German shepherd was found with its head crushed in a suspected ritual killing.
The missing canines range widely in size, breed and age.
"The dogs seem to vanish into thin air," said Debbie Blackwood, director of the animal shelter in Twin Falls, Idaho.
Officials say some 30 dogs have gone missing in recent months in Twin Falls and nearby communities in an agricultural region in south-central Idaho known as the Magic Valley.
A man and his young daughter hiking along the north rim of the Snake River Canyon northeast of Twin Falls earlier this month discovered the remains of a German shepherd that had apparently been stoned to death, Blackwood said.
The dog, found in an area known as the Devil's Corral in neighboring Jerome County, appeared to have suffered a "ritualistic execution" in which its head was crushed with rock and its carcass covered with a purple cloth, she said.
The case has prompted the Humane Society of the United States to offer a $5,000 reward for information leading to a conviction in the dog's death.
The incident was under investigation, said Jerome County Sheriff's Deputy Rick Ustick.
No one has stepped forward to claim the dog.
It was unclear if that case was linked to the rash of dog disappearances, authorities said. Dogs have been removed or released from private yards, unleashed from chains or failed to return home after roaming.
"Animals go missing every day. What's disturbing about this trend is that there is absolutely no trace of them," said Lisa Kauffman, Idaho director of the Humane Society of the United States.
John Goodwin, head of animal cruelty policy for the Humane Society, said it was unlikely dogs were stolen by people engaged in dog fighting, which is illegal in Idaho, because it was rare for those involved in the activity to use just any dog.
Twin Falls spokesman Josh Palmer said city officials on Wednesday consulted with the Humane Society and other animal rescue officials about the missing dogs.
Meanwhile, authorities were asking residents to report "any unusual activity, like the stalking or taking of pets," he said. (Editing by Alex Dobuzinskis and Lisa Shumaker)