[R] How to store and manipulate survey data like this?

[Walter Anderson]

I have to process a set of survey data with questions that are formatted 
like this;

1) Pick your top three breeds (pick 3)
  1  Rottweiler
  2  Pit Bull
  3  German Shepard
  4  Poodle
  5  Border Collie
  6  Dalmation
  7  Mixed Breed

and the answers are formatted like this:

Respondent, Question1
1, "1,4,7"
2, "2,7,5"
3, "6,3,5"
4, ""
...

Any suggestions on how to preprocess the file to be able to do things 
like frequency analysis for breeds?