Is urinary pH formulated food bad long term?

[Gizm0]

I have 7 cats who are on a diet which makes their urine a pH of 6.3 or less. Only one needs to be on it as he has crystals, but I rather avoid a blockage before it happens because dealing with it is so more expensive than just buying special food, so they all get fed it, including a 16 year old senior. I read somewhere that a diet like this can cause issues with their kidneys if fed long term, especially with older cats. I can't remember where I read this, and I can't really find any information about if these types of food cause future problems. The food is Purina Pro plan if it matters.

Does anyone know if these types of foods can cause problems? Or had any issues themselves feeding their pets these foods long term?

 

[FeebysOwner]

Hi. I don't use Purina Pro, but have fed Feeby both Hill's C/D and Royal Canin SO for 10 years now (she is 15+ yo) and there has been no issues with her kidneys. She has a full blood panel run twice a year and so far her kidney function is fine. She had bladder stones so bad that she had to have surgery before she started these foods. She's been stone free (knock on wood) since.

A lot of people will tell you that dry is not good at all, and specialized urinary food is unnecessary if the cats are eating wet food and drink adequately. While there may be some truth to that - all I know is what I know with Feeby. And, up until about 3 years ago, she was eating only the dry version - although she is an avid water drinker. Since I added the canned versions of these foods, she has pretty much strayed away from the dry. I do give her some Fancy Feast pate as well, just for flavor variety.

 

[mrsgreenjeens]

With ll that's going on inthe world right now, you may not get specific answers here, but I think this is something your Vet could answer. Long term for the cat that needs it should be no problem, however, for the cats who don't need it, I would think that it might actually lower their PH too much, but really am just guessing. Does your Vet know you feed it to all your cats? Our Vet always asks us what we are feeding our cats whenever we go in for their regular exams, so if you have told them and they don't have a problem with it, then I guess you're good to go.

 

[CatGuyAZ]

I've gone through a bunch of stuff with my now late kitty, Onyx, related to uroliths (stones in the urinary tract, usually the bladder) and cystitis. Onyx's uroliths ended up being calcium oxalate, the worse of the two common types, with the other being struvite. Oxalate uroliths cannot be dissolved by means of diet or drugs, while struvite sometimes can be. Any cat can get either kind of crystal, but males tend to get oxalate, while females tend to get struvite. Males have a much narrower urethra, and are much more easily blocked by uroliths (a medical emergency if it happens).

I still have a couple of Onyx's uroliths (the vet saved them for me at my request). I'm weird that way, I guess. They are really nasty, jagged, sharp things. I don't think struvite uroliths are usually sharp like that.

The problem my vet had with a lot of over-the-counter urinary foods is that they're formulated to deal with struvite by lowering the urinary pH, but that just makes the calcium oxalate uroliths more likely.

I found this article that explains it (and mirrors what my vet told me, though with more specifics):

"Dietary & Metabolic Factors. As with struvite uroliths, diet can also influence the development of calcium oxalate uroliths. Cats fed low-sodium or low-potassium diets or diets formulated to maximize urine acidity are at increased risk."​

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and

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"...diets that produce a urine pH between 6 and 6.2 are 3 times more likely to produce calcium oxalate uroliths when compared with acidifying diets designed to produce a urine pH between 6.5 and 6.9."​

The article also mentions that metabolic acidosis can leach calcium from the bones and contribute to hypercalciuria and decreased urinary citrate excretion. It does not mention the relationship between metabolic acidosis and feeding of the type of diet in question.

The Royal Canin SO, which was prescribed for Onyx, was supposed to be formulated to prevent both types of uroliths, not just one. One way it does this is to stimulate thirst, which makes the cat drink more, which in turn reduces the specific gravity (concentration) of the urine. The lower the SG, the less the odds of formation of any kind of crystal. Onyx did increase his drinking a good bit while on the SO.

Cats have kidneys capable of really concentrating the urine, and I read once that their kidneys are so good at this that cats could survive drinking sea water (of course, it goes without saying, but never test this! Being able to live through something isn't the same as being healthy or good), but over the long term, concentrated urine has negative potential health effects, like uroliths and kidney disease. I've had several vets tell me that cats don't drink enough, and anything we can do to encourage more water intake is a good idea.

The cat I have now, Dakota, a 11-month old torbie+white DLH, apparently does not drink at all. I keep her water fresh, replacing it several times a day, but in the two months I have had her, I have yet to see her drink even once. She will check out what's in the bowl when I set it down, but when she sees it's water, she walks away. Her diet is wet food, so it's already better in moisture terms than dry (with which I am sure she would drink), but I keep thinking of those vets telling me that cats should drink more.