We’ve got one for our Dachshund. He’s got IVDD (basically back issues) so he can’t walk too far but he’s young, fit and healthy otherwise. When he has a flare up we take him out in the stroller so he doesn’t go mad inside and to still sniff. It also lets us get outside too. If we go for long walks then we take it so we can all go out.
This is a bit of a sore topic for me as I get fed up of sneering, whispered comments when we’re out with him. It’s his equivalent of a wheelchair – see also various discussions about people parking in disabled spaces and walking into the supermarket.
And yes, I’ll likely also get a rucksack to out him in for walks where strollers aren’t appropriate.