If the only reason that you are considering crating Cash is the recent heartworm treatment, I can tell you from personal experience that I have not found it necessary with three foster dogs that went through heartworm treatment. I just kept them in the house and used baby gates to keep them restricted from my young dogs who like to rough-house and play. My fosters got to mix and mingle with my older adults and did superbly. They got to walk around in my fenced backyard and did fine. I did not find that I needed to subject the three foster dogs to crating after heartworm treatment as long as I used a baby gate to keep my youngsters from playing to roughly.
Shannon
Shannon