MOSFET circuit question
My guess is that there is a short somewhere else. I don't know of any design where you want to short Vdd to gnd. Something else is going bad and shorting your power supply to ground. Try tracing the short all the way to where it's produced.

If when you remove the mosfet from the circuit, the short in the circuit disappears, then the mosfet is bad. But if the short stays in the circuit after you remove the mosfet, then something else is causing the short to gnd.

Once you prove that the mosfets are good, I would isolate the different voltage rails (1V8, 3V3, 5V or whatever voltages you have) to find when the short disappears, that'll give a clue of which circuits to look at. That way you can narrow down your search.