Organise a visit from the Guide Dogs for the Beavers to meet a guide dog / puppy and do a few themed games.
Request a visit from your local Guide Dogs Association. You can do this on their website at www.guidedogs.org.uk/supportus/events/request-a-speaker/ - they are very helpful!
Run some themed games like a blindfolded assault course and blindfolded relay
Consider doing some fundraising to sponsor a puppy!
Check out loads of resources at www.guidedogs.org.uk/microsites/guide-dogs-in-school/