Donkey in Minecraft saddle?

Is it possible to place an item in a horse saddle slot in Minecraft with e.g. A hack client or other unauthorized client modifications of the game Minecraft?

I strongly assume that this is prevented on the server side. But I don't know for sure - probably none here. Because you have to come up with something like that first.

Why don't you use a donkey?

It's about a dupe bug

Small addition, it may help:

You can use the Hacked Client to put boxes (and probably other items) in the inventory of Lamas 🦙. But I don't think about horses, at least I've never seen it.

With which hack clients