It is not a named dog that you ever meet. There is a brief mention of missing pet flyers and finding a collar and bones. That is the extent of what is shared in the story
There is no mention of abuse per se, but one character spends their child separated from family and moving homes a lot because the parent doesn’t want them home after their sibling died.
The story says multiple pets were missing, there were greasy bones on the counter, and in a bonfire, but only a dog collar was found in the fire. However, the author suggests that all types of pets were killed.
In chapter 19, a character has a sewing needle stuck into their eye (paragraph begins "She reached her hand out to swat him off"). Character removes it themself a couple of pages later. The eye is temporarily blinded but recovers vision in the next scene.