First let me apologize for my greeting that didn't expand. I should have caught that. At this point, I think that increase exercise is necessary for her. They are both relatively young and need to burn off excess energy. One novel device that might help is the automatic ball throwing machine. Many hold 5-10 balls and if you can teach your dog to drop the balls back in the machine, it will continue to throw balls for the dogs. You can see one here:
You should also rotate toys for dogs. Only keep half of the toys out at any given time. This keeps the dog from getting bored. Now my large dogs enjoy huge balls like basketballs and soccer balls. They do "kill" them pretty quick but it keeps them occupied and I usually get ones that won't hold air pretty cheap at local thrift stores. My dogs also love a tether ball connected to a rope on a pole. They will hit the ball and it will spin around the pole and then spin back and they love the ongoing action of the ball.
You might also use an underground fence system to create barriers to certain areas of your yard that you would prefer were not destroyed such as flower beds, or patio sets. You just bury that wire around those areas that you do not want the dog to go in.
As for medication, your vet might prescribe Acepromazine. http://www.petplace.com/drug-library/acepromazine-promace-aceproject/page1.aspx
Another prescription drug would be Xanax but I have to caution you not to give any prescription drug to your dog without consulting your vet first.
Many people get Rescue Remedy to help with behavior problems. Be sure you get the kind that does NOT contain Xylitol. You can read about this here:
Your vet may have his own personal choice, but I do think the behavior will be reduced as the dogs age. I hope this information has answered your question and you found the information helpful. If you have further questions or need clarification, just hit reply so I can address your concerns.