You can buy interactive feeders from nearly any pet store in your area. If you need to keep your dog busy and your schedule is too full, you can fill it with food and let them play to their heart's content. Let them work for their food and have fun while doing it.
Summers are brutal when you are covered in fur. A nice swim might be all your dog needs to have a better than average day. Take them to the local swimming pool or buy a kiddie pool. If you have a pool in your yard, you can buy a bunch of toys to make things fun for them.
Sometimes you need to get away from everything. Maybe you decide to go to the beach or take a hike. Remember that your dog needs a break too. Take them with you and enjoy the outing together. Remember to take treats and toys to keep them busy when things get a little boring for them.