I have not owned a cat in a long time due to allergies. However, I have helped friends with feral and unadoptable cats. They don’t always adjust very well to changes or being kept indoors if they have had their freedom. So, I guess I agree with your vet.
Often the best solution, in my experience, is to find an indoor/outdoor sanctuary that accepts cats, make a donation and try to get them in, unfortunately often these places are filled beyond capacity.
Example, if you could find a place like this in your area: http://www.winslowfarm.com/index.html
http://www.winslowfarm.com/cats.html
Hope this helps
