There are a few dogs out there that listen well enough while hunting that a e collar or shock collar are not necessary but for the majority of serious hunting dog owners sooner or later you are going to need to think about a e-collar.  When it comes to E-Collars there are almost as many choices as guns and shells.  Professional dog breeder Kelly Olson wrote a great article about e-collars and talks about a few different collars she really likes and why.  If you're in the market for a new collar check out Kelly's article:   E-Collars for Gun Dogs