Thirty two-year-old Kirsty has links to Leominster and Hereford and was last seen at around 2pm on Friday.
Kirsty is described as white, 5ft 6 inches tall, of medium build with long brown hair.
A spokesman for West Mercia Police said: "It is likely that she’s with her dog, Honey, who is a short-haired black collie cross lurcher with some white and tan on her face and chest.
"Officers, along with Kirsty’s family, are growing increasingly concerned for her welfare."
If you see Kirsty or have any information about her whereabouts please call 999.