I have 2 heelers. I recently have taken on more hours at work and am not home as much as I used to be. I have fenced off a long area of my yard and keep my dogs there when I am at work because they totally destroyed my landscape and yard in a matter of 2 days. I have bermuda grass which gets traumatized if you walk on it a couple of times. Needless to say, the grass in their area has died and now they are in mostly dirt or mud pit whenever it rains even a little bit. I feel this can't be healthy.
Is their a kind of grass that can withstand their stampeding that won't look bad if it spreads to the rest of my yard? Also, should I be treating their area with anything special? I always pick up the poop, but they still urinate in there.

The simple answer is no, there is no grass that can stand up to continual pounding. I always suggest a deep mulch for a dog run. Urine is absorbed immediately and converted into harmless nothing. As for the poop I would probably try burying it in the mulch and see how that goes. I leave my dog's poop in the yard untouched and it disappears in four days.