Staffy dogs are the same they get jealous of babies getting all the attention, I worked on a Cattle station in Oz, my neighbor had one that was an inside dog, when they had a baby, they sensibly chained it up outside, he took the dog out one evening to go Roo shooting, having just injured the Roo, the dog jumped off the ute, and ripped it apart so viciously, it shocked him so much, that when he got home he shot it.