The animals that SPANA treats are owned working animals and we have no legal authority to take animals from their owners.
SPANA works hard to encourage owners to take the welfare of their animals seriously, to bring them for regular check-ups, farriery and dentistry. If we were to refuse to return animals to their owners we would very soon find that the number of animals we treat would drop massively, as owners would stay away from us. Animal welfare would suffer as a result.
A working animal is often the only means some people have of earning a livelihood and taking animals away from their owners doesn’t teach them about taking responsibility for them, so the likeliness is that they would soon replace the donkey with another and the problem would simply continue.