N.
We took both our 75 lb labs to MelloDee Middleton at GermelHaus She has trained search and rescue dogs. She is wonderful. Our 'girls' love her. She is in Princeton which is just past Allen, but it only takes 45 mins from Lewisville. She keeps the dogs for training for 2 weeks. When we went 3 years ago it was $600 for the 2 weeks. It sounds like a lot, but it was sooo worth it. If our dogs are across the park from us we can call out down or just give them the hand signal for down and they hit the ground and stay there until we come and get them. You have to see it to believe it. Everyone we meet at the park is always so impressed with the behaviour of our labs. She also boards for half the price of the vets and has a lot of land so the dogs are not stuck in crates the whole time. Our labs come back and sleep for a week after being with MelloDee for just a weekend! Her website is www.germelhaus.com
Good luck