Question
Pros and cons of landscape rock (Lava vs Granite.. etc).  Have a couple of big dogs that like to dig  ... and tired of tracking in mud.  We have used cypress, and other types of mulch in the past....live in Dallas Texas area

Answer
This question has come up before and unfortunately, there is no easy answer with large or active dogs. You are always going to have some maintenance with dogs like this.

Lava Rock is sharp and course and is a bad idea. Any large or course rock is not a good idea.

Crushed granite, M10, Chirt, mini slate chips, peagravel etc. or any small crushed stone is the best if you want to use stone. Note however, that when crushed stone gets tracked in your house it's a nightmare and can destroy hardwoods.  So only use crushed stone if you have some sort of distance or barrier between the active use area and access to your home.

Large shredded Mulch is the best I have found. Larger pieces take longer to break down and don't track in as easily.

Other than that try a large pen and concrete the floor. I keep my dogs in a pen about 16x16 during the day with heavy layer of hardwood mulch then release them in the am and pm for an hour to run the yard, which is all grass. At night they stay in side.

Good Luck

Sean J Murphy, LA,ISA, LEED AP
Please check out my blogs and articles on landscape topics like this on my websites.
http://www.seanjmurphy.com
http://amenityarchitects.com