Center, Pike, and Winona all have fishing with sandy beach areas and parks. Walking trails at Winona and Pike. (Both are beautiful trails!) Dog swimming would probably be best at Chapman or Tippe or one of the more residential or fishing lakes in the area, not the ones affiliated with the parks. We have a boat on Tippe and I have seen dogs swimming there off of boats and the shore. (Tippe is my fave!) You might want to try the link to
Uniquely Kosciusko for more info on the area and all of the lakes. Hope this helps and enjoy our area!