its awesome that you give your doggies so much exercise and attention! For most dogs, its the lack of exercise thats the problem.

The things to worry about when you're running your dogs a lot (especially since they're getting older) are worn pads, dehydration/heat exhaustion, bloat, and arthritis. Check their pads after each run, they should feel rough, if they're smooth that means they are worn out and need to see the vet and stay off their feet. This can be prevented by putting booties on them, with good traction, similar to sled dog booties.. I've seen a lot of runners use these on their dogs! they also help with hot pavement. Make sure you do keep them hydrated and don't run them when its too hot out. However, you shouldn't let them down a large bowl of water after running hard, because it could lead to bloat (especially in large, deep-chested breeds). Also wait at least an hour before/after running to feed them. Some older dogs can begin to develop arthritis, so just keep an eye on how they look and if they seem to be in any pain while running or afterwards.

I am so not an expert on this, but my sister runs 5 miles with my dog 3 or 4 days a week, so I've already asked my vet/other runners about everything to look for. It sounds like your dogs are very loved and well cared for I wish everyone would run 10 miles with their dogs - it would solve a lot of destructive behaviors, barking, and loneliness that also causes so many pups to end up in shelters.