Hello....

I would build Crayola up to the 10 miles over a period of time. It will take at least one month. You don't want him to have heat exhaustion. Running with him that much is actually not recommended. I have a Lab who is incredibly athletic. We were advised that jogging constantly and running is not really good for her in the warm months. Dogs do not function like we do, it is much harder for them to breathe properly in these warm months....especially in CALI. Also, water breaks are needed MUCH more than 5 miles each. Every 15 minutes is best.

Sorry if I sound so mean :-) I wish the best for you both - have a great summer :-)