Good questions, Dr. Sood.  So sorry it took me a bit to get back to you.  Quite often the cysts will just expand the size of the renal capsule, so the kidneys just look "big." They are sometimes irregular but not as often as "big." Dr. Little reported that the sediment was quiet but not whether there was protein present in urine. If there were, I suspect she would have reported that as well. So UPC isn't going to say much. There is still good concentrating ability in this cat particularly if he eats both a moist and dry diet. There is lots of controversy about renal diets and whether protein restriction or the attendant phosphorus restriction is really the benefit since those two characteristics have not been tested separately. In additon, the research done has only been for a duration of feeding of around 4 months. Our renal patients typically live a lot longer than that. There is a genetic test for Persian Autosomal Dominant Polycystic Kidney Disease that is done at University of California Davis and probably elsewhere by now. It doesn't tell you how seriously the cat is affected. It is intended to help diagnose early and remove cats from breeding programs. 

Good thoughts Dr. Sood, though the kitty's indoor lifestyle might put parasites lower on the list. Another form of confirmation of bilateral renomegaly which might either change the differential list or confirm a diagnostic suspicion would be abdominal ultrasound. Naturally, in the Persian breed one must include polycycstic kidney disease on the differential list. A few other causes are often not bilateral, such as pseudocyst, hydronephrosis, abscess or hematoma. Since this kitty has no symptomatic complaints, ethylene glycol is off the list as several symptoms pre-date renal effects. 

Can I play? Let's start with ruleouts for a young Persian cat. Here are some questions? Body condition score? Painful kidneys? PU/PD? HIstory doesn't say. Fever? Rule outs for age and breed: Polycystic kidney disease FIP Lymphoma (virus status?) Lifestyle doesn't really support Ethylene Glycol, not impossible Acute Renal Failure Hydronephrosis Ureterolithiasis Amyloidosis Perinephric pseudocysts Pyogranulomatous inflammation Subcapsular abscess / hematoma Multiple myeloma What did I miss?  Someone chime in on that or work up?

This study was reviewed at the Behavior meeting last summer and is convincing evidence that this pheromone as well as the facial pheromone encourages normal scratching behavior in locations considered acceptable by cat owners. Both can be considered tools in the efforts of veterinarians to help owners create enriched active lives for their house cats.

http://jfm.sagepub.com/content/16/4/291.full.pdf+html   Electrochemotherapy with intravenous bleomycin injection: an observational study in superficial squamous cell carcinoma in cats. Here is a very promising investigation into a therapy for localized SCC that might be interesting as well in this months Journal of Feline Medicine and Surgery. I have successfully used laser for localized SCC but these results appear more promising.