I have chickens and a fox den in the garden. There’s often fox poop outside the chicken run. The chickens are fine and happy, the foxes are now used to them and leave them alone.
I have my rabbits next door to the chickens too and so far, no issues there either (fingers crossed)
My runs are 2.4 x 5, one joins onto the next but the animals are separate. The runs are made from 2.4m fence posts dug in 40cm. No concrete. There are fencing gravel boards top, middle and bottom. Welded wire is used all round and over the top. The joins at the top are sealed with twisted wire. The wire is not dug in.
I’ve then laid paving slabs on top of sand all around the outside.
The chicken coup is the big igloo run. We had the 3m one and soon tired of moving it every couple of days. It trashed the lawn and didn’t give them as much space as I would like (4 birds).
Hth