Just wash your hands before touching your face any time you are repotting. Wear gloves if you can, I personally don't wear gloves, because I can't feel what I'm doing.
Poo as fertilizer can be too concentrated for smaller trees and shrubs. Also some animals excrete salty urine, and will urinate as they deficate. The salts can burn your trees. Ideally you should think about engineering your benches to discourage cats, possums and racoons. Benches too close to fences and shrubbery along property lines will encourage creatures to visit. Too close to tree trunks is also a problem. On the ground can be a problem.
If it hasn't killed your trees yet, nitrogen is nitrogen, the trees don't care where it comes from. But for disease control, wear gloves or frequent hand washing are key, and mechanically protecting the trees is a longer term solution.