FYI - in case you decide to get another cat sometime. Cats are masters at hiding pain. They have had to learn how to do that over the years in order to defend themselves. If you notice something like a cat losing weight or the third eyelid or blood in urine/feces or anything that is "off" then it's time to round up some extra cash and take the cat to the vet.
Assumptions do nothing but make an ass out of u and me.
We can stick our heads in the sand for only so long before it starts choking us. Face it folks. The pet population is bad ALL OVER THE WORLD!