Jeffrey once owned a dog, to whom he displayed affection. However, this was a ruse and Jeffrey didn't really care for this pet. Instead, he had planned to use its organs as part of a ritual to summon his demon. The dog wore a cone throughout its entire appearance, and once Jeffery got his hands on a special ingredient - Dean Winchester's blood - he killed the dog mercilessly, much to Dean's disgust.
The dog was obtained from the Idaho regional animal shelter, and at her first appearance, she had gone through quite a couple of surgeries and obtained stitches.