Man's best friend just became man's biggest mystery.
At least 40 dogs have vanished from Wise County, Texas since November, and authorities say they have few leads for the missing canines.
Wise County Sheriff David Walker could only speculate what's happening to the pooches in his jurisdiction north of Dallas.
"Could they be using them in dog fights? It's possible," he told WFAA. "This is not normal, and it feels like something is wrong. It leads you to believe someone has taken our dogs."
Police say there's currently no physical evidence -- let alone a suspect -- proving that the dogs were stolen, NBC-DFW reports. At this point, there are only heartbreaking stories from worried owners.
Jack, a two-year-old black lab, has been missing from the Lewis family's backyard since Dec. 27. His bright blue collar still hangs above his kennel.
"It makes me think of him," said Robin Lewis.
But it wasn't until Robin turned to Facebook that she realized there may be much more to his disappearance. Two dogs from her neighbor Jana's yard went missing on the same day.
Around the same time, Cassidy McKibben's four-year-old Jack Russell terrier, Lily, disappeared.
Walker appealed to area residents to be on the lookout for suspicious behavior, but it wasn't immediately clear whether the department was putting any extra resources into the case. The sheriff didn't immediately return HuffPost's calls for comment.