"We're trying to remain hopeful that she is around, that she's out there somewhere but at this point, we have many unanswered questions," said Ponce.
Lizzie was staying at Country View Kennels in Modesto with her fur-brother, Russell.
On Monday, the kennel told Carmen and her husband that Lizzie was missing.
"We're all very sad. Even my other dog, Russell, he's not acting like himself," said Ponce.
Staff members at the boarding facility told Carmen they're not sure what happened -- saying Lizzie might have escaped.
Country View Kennels also sent Action News this statement:
"Country View Kennels provides clean, safe and convenient care and boarding options for cats and dogs. The Kennel is in close contact with the family and is aiding in the search efforts. Country View Kennels has and will continue to partner with pet owners, the community, and local enforcement agencies regarding operational procedures to ensure standards are met."
Carmen says Lizzie is a friendly dog and likes to be around people.
She is micro-chipped, so if someone finds her and has her scanned at a shelter or veterinarian's office, it could help reunite her with the family.
Carmen can also be reached at 209-676-0394 if Lizzie is found.