Unable to answer "Is this place wheelchair accessible?" for https://osm.org/way/31001518 via StreetComplete 51.1:

Not really a dog park.
It's mostly a garden (for humans).

Attached photo(s):
https://westnordost.de/p/137985.jpg
https://westnordost.de/p/137986.jpg
https://westnordost.de/p/137987.jpg