At least 13 dogs have died and several others have fallen ill in west Phoenix this month, most of them poisoned, according to Phoenix police and the dogs' owners.
The dogs were at three separate residences, on different streets, near 85th Avenue and Indian School Road.
Police said 10 dogs were found dead at one home Thursday.
"My mom hasn't stopped crying," 13-year-old Vanessa Ruiz, holding one of the surviving Chihuahuas, said.
There were no signs of obvious trauma to the Ruiz' dogs, said police.
At nearby Sharlene Becktell's home, three dogs have died since early May.
Cocoa the Chihuahua was stabbed with an ice pick in a burglary, Becktell said.
Two other dogs died after Becktell found "green pellets" in their water dish in the back yard.
"We're thinking rat poison," Becktell said. Becktell said her veterinarian confirmed that her dogs had been poisoned.
Phoenix police officers will be canvassing the area this weekend in a hunt for information, said Officer James Holmes.
"We need to get this stopped," Holmes said.
Authorities are asking for the public's help. If anyone has any information connected to the case to call Silent Witness at 480-WITNESS.