I don't know if this will help you, but our dog's yard is 3/4 of the way around our coop. I take the dogs to a different yard and use that yard for the run on days that I am home. The moisture is no different with or without the dogs. As far as mites ect. go... I dust the coop, yard and dog house with Food Grade Diatamateous Earth. (I think that is how it is spelled.) It is safe for the chickens, dogs and cats if they consume it, and it is even good for their digestion if they happen to consume it, but it kills the bugs. Also, if the bugs are killed by it, and your chickens consume those bugs, your chickens are still completely safe. There are many pesticides that can do harm to your birds. I also use the Food Grade D.E. for my garden when I have one. The first year I had a garden, I used Sevin dust, and it was fine on the veggies, but if you use it on herbs and other tender edibles, it changes the taste of the plant, no matter how many times you wash it. My cilantro tasted HORRIBLE!!! I started to think, if it changes the taste of the herb that much, what are the chances that I am actually consuming Sevin dust that has seeped into the plant?! Another reason I now only use Food Grade DE. It is safe for humans if some is accidentally consumed as well. Just make sure it is Food Grade. The other DE has chemicals that could be harmful to your animals.