My Grand Parents had Barn Cats as Mousers,but they were reasonably well fed as a Full Cat is a better Mouser,as they have more energy.
What kind of a Medical Professional is this Jerk.
One of those arragont Rich People that care more for Mans Creations,than God Creatures.
Spread the word,and see if you can ruin his practice,until he takes better care of his Cats.