Winona is the Apple Family's new pet sheep dog. However, when she begins acting out of the ordinary, Applejack seeks to find out why. The truth is far from what she expected and breaks her heart. An unofficial origin story.
After Spike and Twilight go through the portal from the human world to the pony world something goes wrong. Spike is still a dog, but he starts to notice a few things. He could now understand the other animals perfectly.
Winona just went into heat. Most of Ponyville's dogs are following Apple Bloom around. The Crusaders see no correlation between those two events. None whatsoever.