Most pumps are water cooled, if it is a strictly submersible pump and is left plugged in and running, outside of water, it will burn out.
If in the stats, it says it can be run in-line, as long as it is primed and water is flowing thru it, it will be OK, if running dry it will burn up.
If you could be more specific, and give more info, it would help. ie what kind of pump? submersible? etc
There are many kinds of pond pumps.