This video does a really nice job showing the importance of Dew Claws especially for hunting retrievers, they do serve a purpose. See below.
A short but good article written by Chris Zink DVM, PhD, DACVSMR regarding, “Do the Dew(claws)?
None of our dogs have had their Dew claws removed and have only had minor injuries to two of our dogs — Trey and Dieffenbaker. The best way to prevent injuries to the dew claws is to keep then neat and short. Granted for the health of your dogs feet and to prevent arthritis in the future is its always best to keep their nails trimmed. Long nails lead to jammed feet when running on hard and/or frozen ground and on the slats on the contact obstacles in agility.
Dew Claws Do Have a Purpose! from Erica Christensen on Vimeo.