I'm not a dog owner, never have been one, don't want the responsibility of owning one.
I understand dogs basically need more exercise than they're ever likely to get from humans taking them out for walks.
So what's this doggie in a pushchair malarkey all about?
On a more serious note I saw one of these things inhabited by a pooch in the space on a bus reserved for parents with children in a pushchair. I can see a thread on Facebook or e-elsewhere where there's a confrontation between the two. It's not going to end well!