So I have 2 dogs, a 2 year old hound mix named Penny and a 1 year old border collie mix named Zoey. Zoey is very jealous of Penny to the point that I can't even pat Penny without Zoey getting between us and biting her. How do I fix this, without getting rid of a dog? Is there a way I can train her to be nice? Penny was the first dog and I got Zoey a year later. Thanks in advance.