How soon do calcium oxalate stones recur?

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Mon, 12 Apr 2021 22:37:32 GMT

[quote userid="10320" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229817#229817"] Cats with a history of urinary problems, especially stones, do better on a tinned diet (or fresh meat, if owners prefer)[/quote]

For sure,with oxalate stones, and certainly! The owners should be persuaded!. [There will be no need to bleed them either,]

But watch out for the cats that ppt struvite . Low Mg++"meats" are worth knowing about.

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Mon, 12 Apr 2021 18:04:00 GMT

[quote userid="5904" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229813#229813"]Am Icorrect in now thinking that the latest solution i[geddit] is to wet the unchanged dried food[/quote]

No, only as a very last resort. Perhaps you could point out where I had suggested that was the "latest solution"

[quote userid="5904" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229813#229813"]somehow this, I suppose by dilution?, will keep the oxalate in solution???[/quote]

But yes, providing sufficient moisture in the diet by feeding a wet food will lead to a cat producing dilute urine, in which minerals are much less likely to precipitate out as crystals (=> stones). One of the most useful ways to reduce re-occurrence. Manipulating overall mineral content/ pH etc still useful, but as you are very aware pushing too hard to prevent one type of crystal can often promote formation of another.

[quote userid="5904" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229813#229813"]if you or the owner insists[/quote]

Again, please can you point out where I have insisted on these cats (or any cat) eating biscuits.

I feed my own cat a dry diet, because it suits him fine. He has no history of urinary problems, not in excessive body condition score/ risk of diabetes (probably because he's never been allowed ad lib biscuits), kidney health is currently fine (not bled him in a while, mind, so touch wood) and he gets some dental biscuits mixed in which help his teeth. I don't particularly promote it to my clients, but the dry food genie is out of the bottle and it would be naive to expect everyone to give up this convenience - and a lot of cats do perfectly fine on a dry diet (especially if provided with the correct type of water bowl in the correct location). Cats with a history of urinary problems, especially stones, do better on a tinned diet (or fresh meat, if owners prefer)

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Mon, 12 Apr 2021 14:42:02 GMT

Well, back-in-the-dday the only thing, in NZ anyway, was the offcuts and trimming from the butcher [6 old Pence.]

of course soon meaty tins appeared and now there is a vast range, sensibly packed and sort of takeaway packaging so very convenient with all sort of strange animal protein and fat from all sorts of animals I'll bet.

] not sure when the first tins appeared but they took over until the Go Cat saga when the RCVS got involved and did a survey which showed only that the DFood cats got fat and lazy and this lead to stones and blockage etc. Nothing what so ever to do with food!

I had been very involved with Oliphant Jackson and a leading cat breeder when he discovered the Mg++ problem with some very pedigree stud cats.

The first 2 cases we had were two cats in one household so, of course, it was the owner's fault that their cats got FUS 'cos they couldn't feed them low Mg++ food whereas, I'm sure, it was Oxalate from Go-cat.....

Am Icorrect in now thinking that the latest solution i[geddit] is to wet the unchanged dried food and somehow this, I suppose by dilution?, will keep the oxalate in solution???

I'm just suggesting any meaty-fatty diet with very minimal, [basically] carbohydratein minimal quantities, if you or the owner insists 'cos dried food is so so convenient and odourless with nice biscuity stools..

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Mon, 12 Apr 2021 12:15:20 GMT

Not a trick question just feels like we are talking at cross purposes, which was why I was curious exactly what you thought I was recommending. From my understanding you're suggesting a home prepared fresh meat diet?

FWIW, I'm pretty happy for these cats to go on a variety of tinned/ pouched (is that a word?) wet diets which are, while you are right to say not completely free of carbohydrate, still mostly meat. If they wanted to feed a commercial fresh meat or raw diet I'd be pretty relaxed about this too, but I don't tend to advise they home prepare diets as I worry (rightly or wrongly) that the diet won't be balanced.

You're nicer than me I tend to advise they not be allowed any biscuits!

It feels like we're not actually suggesting anything very different?

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Mon, 12 Apr 2021 06:55:42 GMT

[quote userid="10320" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229796#229796"]what type of diet so you think I'm suggesting these cats be fed?[/quote]

Obviously, from what I've said, a meaty diet, but you can give them "biscuit" as a snack. Any sign of struvite and you've got to go for low Mg++ meat though.

I have a feeling this is a trick question......... and I hope I have got the answer right??

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Mon, 12 Apr 2021 06:16:53 GMT

Anthony, I'm curious - what type of diet so you think I'm suggesting these cats be fed?

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sun, 11 Apr 2021 23:02:32 GMT

[quote userid="10320" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229792#229792"]Unfortunately increased dietary protein intake also increased excretion of calcium and oxalate in the urine, so not quite that simple. Specifically high-oxalate ingredients aren't that commonly used in cat foods.[/quote]

So I did, but I stopped at both these sentences,, of course the excretion is increased if the diet contains more, [except the portion retained as stones or crystal aggregations]!

You can't excrete it if it wasn't there..........

High oxalate ingredients weren't "that commonly used in cat food" For sure, thankfully. eg meaty foods..

But they are now .

And I'm not sure that one could say that dried foods are so high in protein either compared with the traditional meaty foods.

It is amazing how often a "paper" seems to be able to convince people of anything if they want to be convinced.

Sorry Arlo, but you can see why i continue as it's just common sense.

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Sun, 11 Apr 2021 20:44:55 GMT

Unfortunately increased dietary protein intake also increased excretion of calcium and oxalate in the urine, so not quite that simple. Specifically high-oxalate ingredients aren't that commonly used in cat foods.

You might want to read the ACVIM Consensus Statement:

https://onlinelibrary.wiley.com/doi/full/10.1111/jvim.14559

Or this slightly older document on VIN:

https://www.vin.com/apputil/content/defaultadv1.aspx?id=3847272&pid=11154

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sun, 11 Apr 2021 17:13:51 GMT

[quote userid="10320" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229781#229781"]Struvite will dissolve in acidic urine. However excessive use of urinary acidifiers can predispose to calcium oxalate stones. [/quote]

Even in a low, or no, oxalate diet??

Which is virtually impossible, though, in a cereal based diet.I believe. [ie a diet high in oxalate] but happy to be corrected.

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Sun, 11 Apr 2021 16:06:59 GMT

[quote userid="5904" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229777#229777"]Will a change of diet dissolve existing stones?[/quote]

Not calcium oxalate stones. Struvite can be medically dissolved.

[quote userid="5904" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229777#229777"]So is there a "stone-dissolving diet?[/quote]

Hills s/d, Virbac HPM, Royal Canin s/o, Dechra Specific struvite dissolution...

Struvite will dissolve in acidic urine. However excessive use of urinary acidifiers can predispose to calcium oxalate stones. This is one of the reasons why I tend to aim for dilute urine by feeding a wet diet (ie tinned food, meaty food, whatever you want to call it. If someone wanted to raw feed their cat that had urinary problems, I'd be pretty happy with that. I don't think biscuits are necessarily bad for all cats -mine is fed dry, mainly for my convenience- but it doesn't suit some)

I generally prefer to surgically remove bladder stones rather than attempt to dissolve them, but if you know they are struvite then it's possible.

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sun, 11 Apr 2021 14:15:18 GMT

Will a change of diet dissolve existing stones?

So is there a "stone-dissolving diet? I mean more effective than the sensible "prevention" diet.

Will pre-existing stones ever dissolve?

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Sun, 11 Apr 2021 13:11:00 GMT

[quote userid="3169" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229692#229692"]Maybe I'm lax, but why? I'd change diet and wait and see. The stress of trips to the vets, cost etc seems unnecessary.[/quote]

I would say the benefit would be detecting a ureteral stone at an early stage, before significant renal damage as a result. I'm not a good enough ultrasonographer to confidently identify this, so in my hand would be looking at regular radiographs and then I would tend to agree that cost, stress, plus risks or regular sedation etc does outweigh potential benefits. If owners are very dedicated and would definitely want to refer for surgery etc then may be worth doing. If they wouldn't want to pursue that (and from what I understand a SUB is a complex procedure with quite a bit of ongoing aftercare) then I would also tend to lean towards leaving them well alone after changing the diet (I'd check urine SG a few times but the cat doesn't need to come in for that)

Just one situation where there is no one right way, just the best plan for that individual patient

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sat, 10 Apr 2021 19:55:31 GMT

Quite happy to be proved wrong, or questioned, but usually I never am, just ignored, and it seems, either it is just against dogma and the current beliefs, or some just don't accept what is against what they are told or believe.

The dried food thread is a good example. I do wonder how many cats have "not done well" because of this fixated view that dried food can be Ok, always.

Sad really 'cos I thought vets were always supposed to do what's best for animals.

RE: How soon do calcium oxalate stones recur?

Sara Ramsey — Sat, 10 Apr 2021 16:14:07 GMT

And I have thanked people for all their input. I value these forums for tips, advice, experiences and sometimes re-assurance. I use what I read in conjunction with my own clinical judgement and knowledge, patient, owners factors to treat my patients. The plan for this patient is not finalised

It feels like this thread is loosing its way due your frustrations in people not doing what you tell them.

It's a shame and it taints the enjoyment of learning from others.

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sat, 10 Apr 2021 15:43:04 GMT

I think I've told you the way??

RE: How soon do calcium oxalate stones recur?

Sara Ramsey — Sat, 10 Apr 2021 13:02:26 GMT

The why for me would be to check my interventions were achieving the desired effect, and to try and intervene/change plan before ureteral or urethral blockage presents itself.

Thank you all for the imput

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Sat, 10 Apr 2021 12:35:06 GMT

[quote userid="13526" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229732#229732"]60% of oxalate stones recur, so it’s not a certainty - maybe this cat will be in the lucky 40%![/quote]

Or change to a meaty diet and be 100% lucky [ "turboing, the dogmatists will say, but it's frustrating when it's bleedin' obvious!]

RE: How soon do calcium oxalate stones recur?

niamhjl — Sat, 10 Apr 2021 11:45:01 GMT

[quote userid="3169" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229692#229692"]but why[/quote]

The “why” for me would be because if stones are picked up earlier, when they are tiny then you may be able to treat them in a less invasive way. For instance if voiding hydropulsion were an option then you could potentially do that rather than needing surgery. If you wait for the stones to get big enough to cause clinical signs then you’re probably at a stage where surgery is the only option.

for this case, if picking up the stones early would not change your management of them, then maybe there’s not much point. I think I remember a statistic somewhere that 60% of oxalate stones recur, so it’s not a certainty - maybe this cat will be in the lucky 40%!

RE: How soon do calcium oxalate stones recur?

Michael Woodhouse — Fri, 09 Apr 2021 20:14:38 GMT

[quote userid="7002" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur"]I think we should be scanning or radiographing to check for recurrence....but how frequently are people doing this? Monthly? Quarterly? [/quote]

Maybe I'm lax, but why? I'd change diet and wait and see. The stress of trips to the vets, cost etc seems unnecessary.

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Fri, 09 Apr 2021 17:07:29 GMT

I may have got it wrong but, as far as I understand, it is a "wet" diet but with the same cereal based high CHO etc. content so the problems with obesity and diabetes will continue, as possibly will the FUS. etc., because the makeup, apart from the "wet" is the same??

Why not solve the problem surely and completely by feeding a natural 5000+ years of genetics, "meat" based diet??

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Fri, 09 Apr 2021 14:41:09 GMT

Anthony, I'm not sure if it's somehow unclear from the posts, but what Beats and I were discussing above is exactly that - feeding cats with a history of urinary problems an exclusively wet diet

RE: How soon do calcium oxalate stones recur?

Anthony Todd — Fri, 09 Apr 2021 09:47:57 GMT

Nobody seems to mention that most, or all, of the FLUDT cats, with or without stones, can be eliminated by feeding the naturally carnivorous cat a meaty, non herbaceous, diet.

Struvite stone formers will still occur, of course, as they always did, but low Mg++ meaty diets will eliminate them.

This is the elephant in the room, and only slightly larger than the modern cat [!] fed on a cereal based and totally unnatural diet, to say nothing of diabetes.

Why vets seems to ignore, indeed support, this completely unnatural diet, which is the only, and obvious cause, should embarrass the profession!

RE: How soon do calcium oxalate stones recur?

Lucy Fleming — Fri, 09 Apr 2021 06:56:09 GMT

[quote userid="12930" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229621#229621"]isothenuric (?1.006-1.012 in a cat?)[/quote]

You're right - submaximally concentrated, I should say, rather than truly isosthenuric. And certainly not common, especially on dry diets, but achievable and doesn't automatically mean impaired renal function in a well hydrated animal (I see quite a few students and new grads panic and jump to this conclusion looking at urine SG!)

[quote userid="12930" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229621#229621"]Either DGM or Sarah Caney (I can't remmeber which one) used to advise getting cat's urine to below 1.020 IIRC, so that may be where yuo had that target from[/quote]

You may be right as it came through Langford's feline centre for a particular patient a few years ago. To be honest nowadays I tend to advise cats with urinary disease go on a purely wet diet (preferably wet urinary, but any wet if that's not feasible) and then not fuss too much about what the final number is as it seems to be "good enough"

I've not seen a cat need a urethrostomy for years, and the last one was for a urethral tear post RTA, not an obstruction. Could still have a place (and early consideration if long term costs likely to be of concern) but they certainly don't seem to be needed as often any more

RE: How soon do calcium oxalate stones recur?

niamhjl — Thu, 08 Apr 2021 21:53:58 GMT

[quote userid="7002" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur"]has anyone tried voiding hydropulsion when calculi are present...it looks a bit scary but multiple cystotomy are also not good![/quote]

I have had success with voiding hydropulsion of Oxalate calculi... but only in a female dog. I wouldn’t rate my chances with a male cat!!

the above idea of perineal urethrostomy may make this more possible however!

RE: How soon do calcium oxalate stones recur?

Beats — Thu, 08 Apr 2021 21:03:15 GMT

[quote userid="10320" url="~/001/veterinary-clinical/small-animal/medicine/f/discussions/29766/how-soon-do-calcium-oxalate-stones-recur/229620#229620"]isosthenuric urine (which in a well hydrated cat would be perfectly healthy and normal)[/quote]

isothenuric (?1.006-1.012 in a cat?) urine is not normal in my experience.

I'm not alone in thinking that urine SG less than 1.021 in a cat would be quite a feat to achieve in a healthy cat: Factors affecting urine specific gravity in apparently healthy cats presenting to first opinion practice for routine evaluation - Mark Rishniw, Rodrigo Bicalho, 2015 (sagepub.com)

At the risk of going down this rabbit hole too far, it is worth noting that one vet can measure cat's urine SG at 1.030, while another measures that same urine at 1.035, making a lot of these guidelines based on even less sense than usual.

Either DGM or Sarah Caney (I can't remmeber which one) used to advise getting cat's urine to below 1.020 IIRC, so that may be where yuo had that target from.