After over a year of the same behavior from my cat, lethargic, constipation, just not his old self... I discovered what his problem was. Impacted anal glands.
Took him to Flamingo pet hospital for 8.00 they extracted them, my boy is finally back to his old self.
Thanks, but no thanks, sorry, but not sorry.
Sometimes it's a simple problem. Doesn't require 500.00 worth of labs, just a simple thorough examination
Old Veteranirian used to be so much more intuitive.