The first attack happened Friday evening when a woman was bitten on the face by and Australian cattle dog.
The owner of the dog had adopted it nine days earlier and turned it over to city officials, who were to do an assessment.
On Saturday morning, a woman was walking her poodle along a street when she met another woman walking two "pitbull-type" dogs.
Investigators say they owners let the dogs greet each other and then one of the larger dogs began biting and shaking the poodle.
A neighbour tried to stop the attack, but the poodle died after being taken to the vet.
Investigators want to speak with the owner of the larger dogs, who is described as Caucasian, between 30 and 40, with a petite build, blond hair and is possibly named Sarah.
Also on HuffPost