I'm honestly not certain myself, so I've submitted a ticket to find out from one of the admins.

In the future I would suggest doing the same before making a post if you are uncertain. :)

Got word from a UA that this is okay as there are no rules against it.

Personally, I would just like to warn you and make you aware that giving your pet to another user could compromise it if they decide to keep it, leave subeta suddenly or are iced/frozen.

Good luck!