How many other unicorns have baby dragons?

[Kiracub 36]

If Twilight hatched Spike from an egg for an exam, how many other ponies are running around with dragons? Are the dragons taken away afterwards for most of them? Maybe Twi was only allowed to keep him because of her talent?

 

I feel like I'm probably repeating a previous question here, but still. Thoughts?

[M'aiq the Liar 5,804]

Twilight is most likely the only one with a pet dragon, as she is the main protagonist of the current series. And she kept him because growing and training him was both in part a magical study, and to give her some training in motherly ideals that would help her lead a nation once she replaced Celestia.

[LZRD WZRD 1,929]

Ah, MLP's greatest flaw: when you think too hard about it, you end up with more questions than answers. My honest guess is that the writers didn't think it through. My canon explanation is yes, there are other ponies with dragons, they either stay clear of Ponyville or they're all invisible

[Kuyon 43]

Celestia might have also let Twilight care for Spike to teach her some responsibility and maybe to give her a life long friend as well. 

[Kiracub 36]

Ah, MLP's greatest flaw: when you think too hard about it, you end up with more questions than answers. My honest guess is that the writers didn't think it through. My canon explanation is yes, there are other ponies with dragons, they either stay clear of Ponyville or they're all invisible

I like the thought of having another pony with a dragon partner, though. It would have been neat if Trixie had one, for example, who was the opposite of spike, maybe even being a bit bigger with greed, but ultimately weaker. I know they have approached Spike's lack of other dragons around him usually a few different times, but there are still plenty of opportunities there. 

[Visual Spectrum 1,932]

It is possible that other unicorns had pet dragons, but the dragons they raised weren't generous and grew up quickly after becoming greedy. 

[Fawkes The Phoenix 737]

The entrance exam to Celestia's academy was to open the egg, so there are more dragons, but it's kinda disturbing the fact that all those dragons are born to serve some pony, so i have a headcanon, Spike is an orphan who was taken under the wing of Celestia in her academy, and it was him the one who chose to be Twilight's assistant, maybe because he needed a job or just wanted something to do, and after some time Twilight became her mother/big sister figure. So Twilight would be the only unicorn with a dragon assistant, but maybe there are more ponies with dragons as pets...