Beloved Dog Dead, Another Critical After Being ‘Poisoned’ in Yard

Police are investigating a suspected baiting incident that has killed one Border Collie and left another fighting for life in Melbourne.

CCTV shows a woman loitering in the front yard of a home in Underhill Court, Sunbury, about 11pm on Sunday night.

It’s believed the female captured on video poisoned two dogs, a Border Collie and a Belgian Shepard, while they were in the yard.

Rua, aged seven, (left) and Chance, aged two, were allegedly poisoned. (9NEWS)

CCTV captured the woman loitering in the yard for several minutes. (Victoria Police)

The woman can be seen sneaking away but within an hour she had returned and approaches the house again.

The Border Collie, Rua, died en-route to an animal hospital, while two year-old Chance continues to fight for life.

Homeowner Ian Davies described the incident as “unbelievable.”

Homeowner Ian Davis described the woman's actions as unbelievable. (9NEWS)

Chance remains in a critical condition. (9NEWS)

“When you see (the offender) stalking the fence line for 50 minutes…she’s hiding…I can’t believe someone would be out there doing it.”

Police and the RSPCA are now appealing for the woman or anyone who recognises her to come forward.

Six white tablets were found in the backyard, with police now analysing their contents.

She is described as being Caucasian, aged in her late 30’s to early 40’s, and was wearing white baggy shorts and a dark coloured top.