Two years ago I reclaimed my home from renters. The place was a DISASTER! It took THOUSANDS of dollars to make it livable, and I still find little surprises now and then. When they applied to rent from me, 5 years earlier, they indicated it was a mom and dad my age and their 16 year old son. They stated they had one dog.
When I came to renew their lease after 2 years, I brought a camera. The place was still in good shape, but they had moved the son's girlfriend in, as well as their older daughter and her three kids. This is a 2 bedroom home, BTW. I also saw a cat (it is in one of the photos), but somehow didn't think about them having said they had only one dog. I never looked in the rear yard when I was there at that time.
They moved out owing me several thousand dollars in rent and about the same in damages. When I got the house back, I had to remove a lot of flooring that had pet stains on it. I had to patch huge holes in the wall, and when I went out back, the ground was hard, bare dirt. It looked like the dog (neighbors later told me that they had had SEVERAL pit bulls) had killed off the grass, and the topsoil was then free to wash away when it rained. All that was left was REALLY hard and compressed clay. They had also dug a few "pits" and had chewed through the wires to the whole-house air conditioner.
It took me several days with a shovel to loosen it up into BIG chunks, then time with a rake to break those up. It was a very hot, dry summer and I eventually got a presentable lawn, but it was a HUGE effort. This area was only 12'x20'. A professional quoted me $900 to do this work (that was the low bidder).
Side note:
The tenants were insistent that there was never grass in that rear yard, but I have receipts from having it mowed up until the time they moved in. I pulled up Google Street View at one point, hoping to see what size the tree I planted when I moved in was at that time... but Street View took me to the rear of the house instead, looking into the yard from the alley. There were items clearly in view that belonged to my tenants, and there was grass covering most of the yard, aside from a path their grandchildren had made from the rear door to their spring horse. I screen captured it and included it in my collection efforts, which proved futile anyway.
The back yard was just slightly softer than concrete. It would not have shown footprints in dry weather, and probably not even on a wet day, it was THAT hard.