How to crush dog food?

My vet has prescribed the Royal Canin Early Cardiac Veterinary Diet dry dog food, but the pieces are too large for my 11-year-old Maltese to manage. Aside from chopping it up piece by piece with a knife, what's the best way to crush the food into smaller pieces, without making a big powdery, crumbly mess? (I have a juice blender but not a food processor.)