Royal Canin Urinary SO vs. Hills Prescription X/D

My cat had a problem two years ago with Calcium Oxalate stones. She had surgery to remove them from her bladder and now she is supposed to eat Hills X/D. She prefers can food but will not eat the X/D. She will nibble on the X/D dry food so I have been mixing some dry with some Fancy Feast and hoping that it is doing some good. She has been OK for two years but I really would like to get her on something that will be better for preventing the Calcium Oxalate stones that she will eat.

I hear a lot of people say that their cats LIKE the Royal Canin food so I was thinking about switching. I was just wondering if anyone here used that food to prevent Calcium Oxalate stones. My vet refuses to discuss anything but Hills so he is no help with this. I want to try to get her onto something that will help her and that she will actually eat. So I would be very interested in hearing of anyone's experience with Royal Canin and treating Calcium Oxalate stones and/or crystals.

Thank you.

Karen

It is suppose to treat BOTH types of stones. And prevent futer stones of BOTH kinds from redeveloping!

Originally Posted by ladybass0711

It is suppose to treat BOTH types of stones. And prevent futer stones of BOTH kinds from redeveloping!

Click to expand...

How since both types need slightly different therepies??

Originally Posted by sharky

How since both types need slightly different therepies??

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I'm not sure, but this PDF has some detailed info. It says "URINARY SO 30TM/MC (dry) and URINARY SOTM/MC IN GEL (canned) are the first and only diets which have been clinically
proven to reduce the risk of both struvite and calcium oxalate urolithiasis."

,....so I'm not sure it's a treatment for oxalate (haven't read it fully), but it claims to "reduce the risk of both".

Thank you

Originally Posted by sharky

How since both types need slightly different therepies??

Click to expand...

Although it sounds counter-intuitive that a food could prevent both types of crystals, i.e., one that develops in pH basic conditions (struvite/magnesium ammonium phosphate) and one that develops in pH acidic conditions (calcium oxalate), one of the main reasons Royal Canin Urinary S/O is formulated to prevent the occurrence of both types of crystals is because of RSS methodology. To make a long complicated story short, RSS methodology predicts the crystallization of urine. Under conditions where the RSS < 1 (undersaturated), stuvite crystals will not form, and under conditions where RSS < 12 (metastable) calcium oxalate crystals will not form. Royal Canin Urinary SO is formulated to produce urine in cats that meet these requirements and therefore, this food can be labelled for management of cats with struvite or calcium oxalate urolithasis. RSS methodology sounds pretty theoretical at first glance, however, published feeding trials have shown that these principles hold true in vivo. The presence of DL-methionine (as an acidifier) and sodium chloride (salt) in the dry food also contributes to increased water uptake and urine dilution. From what I've read in the literature, RSS methodology is only one of many factors that contribute to urinary pH.

Right from the Waltham's website (the PDF in one of my other posts):
http://www.walthamusa.com/Learning Center/SO30.html

"RATIONALE:
Ten years ago, the majority of uroliths removed from cats were struvite (magnesium ammonium phosphate). Since struvite formation is highly dependent on urine pH, diets designed for managing struvite uroliths encouraged the production of severely acidic urine and were highly restricted in magnesium.

In the past ten years, there has been an increase in the incidence of calcium oxalate urolithiasis. The dietary management tools for struvite (acidification and severe magnesium restriction) have been suggested to be risk factors for calcium oxalate urolith formation.

The management of calcium oxalate urolithiasis is far more challenging than struvite urolithiasis. In humans, calcium oxalate uroliths can form in urine across the full range of normal pH values (4.8-7.4). Urine pH manipulation cannot be used to reliably manage calcium oxalate urolithiasis, nor is the restriction of dietary calcium and oxalate effective in preventing oxalate urolith formation.

Diets specifically designed to prevent one type of urolith may greatly increase the risk of the other type of urolith forming. Waltham Science has taken a safer approach and invested years of research in developing a single diet which effectively reduces the risks for both types of uroliths simultaneously.

URINARY SO 30TM/MC (dry) and URINARY SO IN GELTM/MC (canned) are the first and only diets which have been clinically proven to reduce the risk of both struvite and calcium oxalate urolithiasis.

Urine Evaluation Using RSS:
The desire to develop diets which effectively manage both struvite and calcium oxalate urolithiasis in pets led Waltham to explore complex research methods for predicting urolithiasis risk in dogs and cats.

The predominant urolith in humans is calcium oxalate and more than 30 years ago, human urologists began looking at ways of predicting the risk of calcium oxalate formation in human patients.

The result was the development of a research methodology known as RSS or Relative SuperSaturation. This methodology involves the analysis of 12 constituents of a collected urine sample, as well as the determination of its pH. These data are then analyzed using a computer program that calculates the concentrations of the large number of possible interactive complexes between all ions present in this urine.

Finally, the program calculates the activity product of the urine sample for a given urolith and divides this number by the known constant thermodynamic solubility product for that urolith to determine RSS. If the sample’s activity product is less than the constant, then RSS < 1.0 and the urine is said to be "undersaturated" for that urolith.

Using RSS to assess the risk of struvite urolith formation in cats:
If a diet has an RSS for STRUVITE of:
\t
The urine produced by cats fed that diet is said to be:
\t
And the risk for STRUVITE urolith formation is:
Less than 1 (Undersaturated)
New struvite uroliths will not form, existing struvite uroliths will dissolve

Between 1 and 2.5 (Metastable)
New struvite uroliths will not form
Any existing struvite uroliths will not dissolve and may grow

Over 2.5 (Oversaturated)
New struvite uroliths may form
Any existing struvite uroliths will grow

Using RSS to assess the risk of calcium oxalate urolith formation in cats:
If a diet has an RSS for calcium oxalate of:
Less than 1 (undersaturated)
New calcium oxalate uroliths will not form
Existing calcium oxalate uroliths will not grow

Between 1 and 12 (Metastable)
New calcium oxalate uroliths will not form
Any existing calcium oxalate uroliths may grow

Over 12 (Oversaturated)
New calcium oxalate uroliths may form
Any existing calcium oxalate uroliths will grow

URINARY SOTM/MC IN GEL (canned) and URINARY SO 30TM/MC (dry) are the first and only diets which have been clinically proven to aid in the management of both struvite and calcium oxalate urolithiasis in cats.

Idiopathic Cystitis:
A clinical study examined the recurrence of signs of lower urinary tract disease in 54 client-owned cats with idiopathic (or interstitial) cystitis. Recurrence rate for the year prior to the beginning of the study was 96%, with 52 cats having had at least one episode of LUTD signs in the previous year.

Signs did not recur in 89% of cats fed URINARY SOTM/MC IN GEL in canned format, while 61% of cats fed the URINARY SO 30TM/MC in dry format did not have a recurrence of signs over the 12 month trial period.

The proportion of cats in which clinical signs recurred was significantly lower in the canned diet group than in the dry group. Canned URINARY SOTM/MC IN GEL is the only diet proven to be beneficial in the management of feline idiopathic cystitis."

Thank you ... I do like 1+1 to =2

Thank you so much. That PDF is quite interesting and very helpful. I think this might just be the answer to my little girl's problem. Misty had a battle with Calcium Oxalate stones BUT it was AFTER being treated for Struvite stones which she tested positive for at first. So this food might be the answer. Misty's brother Tino also had Struvite stones first and then was treated for Struvite stones and got worse. He had surgery too and they removed a large stone which tested positive for Calcium Oxalate. This leads me to believe that the treatment for struvite only can very well create the opposite problem. Unfortunately, my dear Tino has since passed away, last month from something unrelated but I sure would have loved to see how he would have done on this food too.

Thanks again for the information.

Karen

Carm,

Thanks so much for all of that information. Your time is very much appreciated. I am so glad I came here to ask about this. I actually never heard of Royal Canin and someone mentioned it to me and I asked the vet and he said he didn't know much about it but why not just continue with Hills. I explained that if I can't get Misty to eat it and if mealtime is going to be stressful, she is not going to benefit from it. Someone I was talking to the other day told me her cat is VERY picky and she does like this food so I figure why not at least look into it. Like I said mealtime shouldn't be stressful. That never helps with urinary issues, it tends to bring them on.

Thans again.

Karen

Even my vet wasn't sold on the struvite and calcium oxalate claim, compared to the tried and true Hill's line. After sifting through a few scientific publications and doing my own research, RSS methodology seems like a valid claim and I suspect that some new findings will be coming out in the next couple of years.

Unfortunately, cat nutrition research is lacking and most of the studies are published by the cat food companies themselves! The pet food industry is so huge in terms of profit that the cost-benefit of conducting pet food research is to their advantage. Interestingly, RSS methodology isn't entirely new or limited to our furry friends. Calcium oxalate stones are also common in humans and researchers have been using RSSes to predict crystal formation there too.

Back and forth.... hee hee! Is there a chat room on this forum?

Karen,
You're most welcome for my unofficial advice. I think we can really learn a lot of one another when it comes our pets. Your case with the struvite crystals then calcium oxalate crystals is all too common unfortunately. Calcium oxalate stones are even worse since they do require surgery! I hope to see some long-term feeding studies being published by Walthams in the next couple of years. I'm actually thinking of emailing the lead scientist to ask him some questions.

Pico HATED the Hill's food and refused to eat it....it was a struggle getting him through the 6 weeks of S/D. He was on C/D for about a month when we switched him over and has been gobbling it down ever since. I also like the ingredients better than the Hill's line but again, it's a personal preference for the owner.

Good luck! Hope your kitties stay happy and healthy!