Meth-laced hot dogs have twice sickened a family's pups. Police don't know who's responsible or why.

Police in Colorado are investigating after, they say, a family's pooches were sickened by methamphetamine-laced hot dogs placed in their backyard going back months

Police in Colorado are investigating after, they say, a family's pooches were sickened by methamphetamine-laced hot dogs placed in their backyard going back months.

Investigators believe someone is targeting the pets in the incidents dating to November, Broomfield police said on Facebook. On two of those occasions, the dogs ingested the meth and became sick, police said.

Jillian Frank told NBC affiliate KUSA of Denver that the strange ordeal began when her mother, a vegetarian, found a hot dog on her patio in Broomfield, a city about 18 miles northwest of Denver, and "cracked it open." It contained a crystal-like substance that police said later tested positive for meth.

Frank said the family at the time chalked it up to a random case of animal cruelty.

“She has no enemies or conflict. She doesn’t have any neighbor conflicts," Frank said of her mother. "We just kind of assumed this was a random, malicious act of animal cruelty.”