I get asked this question all the time: You got a saddle for that pony? People are, of course, referring to the (always growing) Great Dane, Talos. Ha, ha, very funny, I say. I must hear it once a day (or more).
While Talos and I visited a friend of mine, she said "Hey, I've got a pony saddle I swear would fit Talos."
"Go get it! Let's try it on him" I said.
We just draped it over him (no cinch yet), and he was a-ok with it resting on his back. I'm all for desensitizing him to the saddle, cinching it up, and walking him around with the saddle on. Just for snicks. As long as Talos finds it rewarding (meaning: as long as he gets to eat lots of treats), I'm all for it.
It's great socialization for him – the more things he views as "normal," the more well-adjusted he'll be. The more adjusted he is, the less he'll spook or be scared when he's out working with his person.