Urine analysis - specific gravity?

My giant baby cat, Avery, (he's 4 years old, I just call him a giant baby because he looks cute but is 10 lbs.) has a history of bladder stones so I've kept him on wet food with added water for a bit over a year since I adopted him. I gave him strictly wet food, Medi-cal Preventive, and I'd add 50-100% water (by volume) on top of the canned food to encourage water consumption. The animal shelter told me it was cheap dry food that caused his struvite stones in the first place.

I took him to the vet for a checkup recently, and blood work and urine analyses were conducted.

Today, the vet called and said his blood work came back fine, but that the specific gravity in his urine analysis was outside of normal ranges. He said a cat should have '10-40' and not below, but Avery has '10-12'.

He indicated that it could be a sign of early kidney failure, or that I'm force-feeding him too much water by mixing into the canned food. The vet suggested that I refrain from feeding him much canned food, and stick to dry only (with water available) to test his 'concentrating ability'. I will then take him back to the vet for another test in a month's time.

Can anybody comment on these specific gravity figures? Is there a 'layman's guide to vet-speak' that I can read up on? Thanks everyone for your help!!!

This article gives a pretty good breakdown of the urinalysis.

http://www.peteducation.com/article....articleid=3136

I think your vet meant that he wanted to see 1.040 or more. The article states that 1.015-1.050 is "normal".

I don't have personal experience with kidney failure, but I don't think I would rely on the urinalysis by itself for even a preliminary diagnosis. The blood work should give more clues. Do you know what the BUN and Creatinine values were?

Here's an article on kidney disease...

http://www.peteducation.com/article....&articleid=350

FWIW, I disagree with his advice to feed him dry food as a test. At the most, I might back off on the added water but I wouldn't feed him dry food.

Thanks for your help, Beandip! I love your name!

BTW, the dry food that the vet suggests I only feed is Waltham's (Royal Canin's) Urinary SO. It's the food that manages the pH such that both struvite and calcium oxalate crystals are minimized.

Since Avery is on antibiotics for his chin acne, I will continue to feed him a small portion of canned food to grind his pill into. Perhaps I'll do half dry and half wet?

I wouldn't do that, personally. I would get a second opinion. I don't have experience with kidney failure, but I do have a lot of experience dealing with bladder crystals, stones and infections. I did a lot of research about my cat's diet, and my conclusion is that dry food's only benefit is for humans (the convenience factor).

My cat was on prescription urinary dry food for a year and a half. During that whole time he was miserable with repeated bladder issues. It wasn't until I eliminated dry food from his diet that he showed improvement. He's a happy and healthy guy, now!

What I'm saying is that you're doing the right thing now. I think the vet is leading you away from the best course of action.

These are a couple of my favorite articles on the subject...

www.catinfo.org (all of the info there is great)

http://www.littlebigcat.com/index.ph...needcannedfood

http://www.littlebigcat.com/index.ph...=show&item=017

http://www.littlebigcat.com/index.ph...=show&item=003

I agree with getting lab values - you need to know your kitties BUN and Creatinine levels.
A sp grav of 1.012 is pretty dilute, you def. need to figure out why. Here is the appropriate page on sp grav on the best site on the net (in my experience) on chronic renal failure (crf):
www.felinecrf.org

http://www.felinecrf.org/diagnosis.htm#USG interesting to read some of the other possible causes of dilute urine. As I said, this is a superb site.