Here's skinny on degassing. All wines require degassing, although many do it themselves, naturally. The gas we're talking about is CO2, which given off as a by-product of fermentation. The CO2 more easily releases when the wine is maintained at 68+ degrees, so some wine makers set their temperature at around 72F to help the CO2 release naturally.
When degassing, it's best to use a stirring tool attached to a drill, particularly when the wine is in a carboy. The easiest way to determine if wine is degassed is to taste it. You can also shake some in a closed test tube and see if you get much sudsing. Degassing shouldn't take days but it's best to try it by stirring a few times over 2 days.
One last point, don't try to degas until fermentation is complete. Otherwise it is futile.