As children’s protectors, yes-- working animals.
As media celebrity pets, also yes-- partly because of the little bit of daring involved in keeping and training one.
I, also, have trained hounds, Ms. Akahoshi. My own knowledge and experience strongly suggested that it’s absolutely necessary for a trainer to obtain the hound’s respect, and to be careful never to lose it. The hound can be a companion, a protector, a status symbol (I hesitate to say “pet”), but doesn’t form the kind of pack attachments you see in canines.
It’s at least partly a matter of how they live and hunt. Canines are pack hunters; they work together as a team. Slaver hounds are ambush predators that use surprise and overwhelming jaw strength to end a fight quickly, and usually more or less alone.
As you say, they’re smart. But they’re not dogs.
Edit:
So, as a bit of background, I did train my own slaver hound, Meogoleh, with a good deal of success, but ended up leaving him with Utari when he and I parted ways. He never got along with the Directrix’s actual literal dog, who correctly sensed something dangerous, and I don’t think the Directrix would have been comfortable with her infant son sharing a living space with him.
Then, also, Meo was trained to be my bodyguard, but, about that time I had resumed my precedessor’s martial training and started treating it as my duty to guard the Directrix. It might have been possible to expand Meo’s training to include such things, but, really, it was easier, and also easier on the Directrix’s nerves, to leave him to watch over someone else I cared about.
… though, I guess that might not have gone so well, in the end. Utari, I do still kind of want to know how all of that worked out. Or not.