One link leading to another I spent my office morning by getting more information. I found the following PPT presentation very good because it is so structured.

http://www.agri.huji.ac.il/~hylton/r...%20Disease.ppt

Tigris seems to have the so called iFLUTD. I didn't know that 53,8% of the cats with FLUTD have that version of which the cause is not known. Only 1-3% have a bacteria UTI.

Looks as if the vet tried to exclude all the other reasons (for the 46,2% non iFLUTD) which is urethral plug (small stones and tissue in the urethra), urolithiasis (crystals), bacterial UTI, or malformations of the urethra.

The problem is that many recipes like diet food (they say that most foods these days are already formulated in a way that they acidify the urine- plus these foods that prevent struvite crystals can bring oxalate crystals) or even the plumbing surgery Boots and Fister had will not work in a case like that.

He may have to get cortisone to get rid of it (which is what my vet was talking about) and in the future it is checking all the time for pea biscuits and behavior.

Sorry for boring you all with these details but I simply have to understand what's happening- it leaves me feeling a little more in control