I would make tha change gradually, unless she is on one of the foods that is on the recall list. If that's the case, I'd switch her over to plain boiled rice and start mixing the Canidae in ,switch the food gradually, over a period of a week or so. Start with a mixture of 15% new and 85% old and feed that for a few days, then change it to 25% new and 75% old and feed that for two days or so then step it up to 50-50, and finally end up with a combo of 75% new, 25% old.  If your pup seems to be having digestive problems, i.e diarahea, take it back a step and do the transition even more slowly,  take your time, the key is to get his/her body used to this new food and help it to adjust gradually. If your pup is used to having wet food as well, Canidae also makes a great canned food that is available at some local pet supply stores.
Hope this helps, PM me if you have any questions!