I have read all the thread about Boots' surgery and it looks as if he had an infection plus crystals. He got antibiotics against the infection from beginning of August until end September.

Fister's urine being sterile means he had no primary UTI (1-3% of the cats with FLUTD have one). But he had crystals (20% of all cats with FLUTD have them). So he needed no antibiotics then.

Tigris has no crystals and a secondary UTI for which he gets the antibiotics.

The bad thing is the chronically inflammated urethra. This can be kept down by the pred.

What I would like to know is:
Did Fister or Boots have any problems like an UTI after the surgery?

Did your vet inform you about the risk of getting more UTIs once the surgery is done.?

Thank you Linda, for the link. That's exactly what it is- and I also hope it is over once we get it sorted out.