Bladder stone and conflicting food advice

[GuineaDan]

Hi, so one of my guinea pigs had a small bladder stone (he was X-rayed because he had an issue with blood in his urine earlier this month/last month, and he was going in for a dental anyway), and the specialist vet recommended to give him spinach to help break it down. However, as I'm looking online, it says that spinach can often cause bladder stones if given too much.
I'm just confused about what the appropriate amount I should give is, I don't want to make the problem any worse for him.
Currently we have a bag of baby spinach and he's already had some today, looking into it he's probably had too much today, but I'm really not sure.

So my question is, how much baby spinach is advised for a guinea pig with a singular bladder stone to help break it down? Is it not recommended at all?
The specialist vet recommended it, which is why I'm confused that he didn't give any warnings about it.

The rest of his diet is hay, a small amount of pellets (reduced since the vet visit, though he wasn't having a ton), a slice of bell pepper and a leafy green. He also drinks a lot of water. He's eating completely fine.
The bladder stone caused some issues earlier this month/last month (although he was given UTI antibiotics, so it's hard to tell what the cause was out of the two), however he's shown no bladder issues since then. He's been perfectly active and happy.

My apologies if this is the incorrect forum, I was considering the Food forum but due to the bladder stone part, I decided to post in here!
Thank you for any advice, I'm just very confused about what to do!

 

[Piggies&buns]

I’ve never heard of a vet advising to give spinach to break down a bladder stone - in boars, if a stone is very tiny it may be able to be passed, but surgery can often be needed if it is not small enough to get past the angle in a boar’s urethra (this can be where they get caught and cause problems)

While it’s a complicated process and includes oxalates as well, you do not want to give high calcium items in large quantities to any piggy and certainly not to bladder prone piggies.
We only recommend feeding a high calcium veg once a week only to any piggy, so in the case of spinach, 1-2 leaves once a week.

Too little calcium can also cause problems and knock the balance but by getting a variety of veg, and a small amount of pellets, then they should still be getting enough.

Most calcium comes from pellets and drinking water. Pellets should be kept limited to just one tablespoon per pig per day only. It’s recommended that drinking water is always filtered, particularly if living in the hard water area.

There is also a genetic element to bladder stones - some piggies are going to be more prone to them - and of course as there is nothing we can do about genetics, all we can do is control the diet.

 

[GuineaDan]

Thank you so much for your response! It was very insightful and cleared up a lot of my questions, I really appreciate it.
I assumed the specialist vet would have an accurate understanding of what guinea pigs should be eating, but I was very confused when every single page said spinach wasn't good for guinea pigs in high quantities, especially those with bladder stones.
He also seemed to recommend no pellets and a lot of wet food. The "no pellets" made me raise my eyebrow, since I know that's supposed to be 5% of their diet. Reducing the amount makes sense, but 0 pellets doesn't.

I will try giving him 1-2 baby spinach leaves a week (he definitely had more than that yesterday unfortunately, but hopefully that won't cause any further issues) as well as reducing the pellets to that amount - my methods of pellet reduction were a bit less precise lol. Unfortunately, my piggies like to pick at their nuggets throughout the day and won't immediately eat them, so hopefully one of them isn't eating both tablespoons lol.
I honestly didn't even think about hard water until you mentioned it, turns out I live somewhere with very hard water, so I'm definitely off to give them filtered water. I'm thinking, especially since he drinks a lot, it's possible that the hard water was a primary cause of forming the bladder stones since his diet didn't have a surplus of calcium as is, especially since the other one was more greedy with pellets.

With hard water, do you recommend switching immediately to filtered water, or should it be more gradual? (like... Half filtered and half unfiltered?) I'm not sure if switching immediately would cause any problems in and out of itself.

 

[Piggies&buns]

No pellets is actually ok to do but you must be sure they are getting the balance of nutrients from elsewhere in the diet through veg and forage. The pellets provide a safety net in nutrients and this is why they are fed but are not strictly necessary in the diet.
I personally only feed pellets about three times a week and the other days I give a variety of dried forage leaves.
They generally eat the pellets fairly quickly but they dont get many (it won’t be the one tablespoon per pig amount). I give them their portion of pellets each scatter fed amongst their hay and veg so they have to search for them (it’s enrichment also). After about half an hour or so, any uneaten pellets I can see are removed but as they don’t get many there usually isn’t any left after that time. Then they fill up on plenty of hay.

Having a wet diet is a good thing to do. Plenty of veg keeps the bladder flushed through and can help bladder health. Fresh grass is also very good
One cup of veg is the recommended amount but I personally do feed a little more than that amount. They get a lot of herbs and leaves. High calcium items are not fed regularly and they don’t get carrot or fruit hardly ever (a couple of times a year)

As I say, there in a lot of calcium in water in a hard water and that can cause problems.
Yes switch immediately to filtered water.

Its a complicated process - too much or too little calcium knocks the balance off and can cause problems - so as owners all we can do is the basics really. Filtered water, limited pellets, a variety of veg and ensuring high calcium items (kale, spinach, parsley, dill to name a few) aren’t fed in large amounts


To add, any changes to the diet will take several weeks to have any effect on the calcium levels in the body going forward but ultimately any change you make will not have an effect on the current bladder stone. As I say, normally the course of action is surgical removal if it is too big to be passed

 

[Wiebke]

Hi and welcome

You can find our dietary recommendations for guinea pigs in this guide here (see chapter special diets). Since conditions vary locally, there needs to be a certain flex to find your own calcium and oxalate 'soft spot' in your own diet. There is a number of factors that play into the formation of bladder stones; unfortunately, diet is very much the only way we have to minimise the risk of them forming. Guinea pig urine (like that in cats) is very alkaline, which means that they are as a species rather prone to urinary tract problems.

The most difficult period are the weeks after a stone removal because it takes much longer for the dietary changes to kick in and any excess calcium to be worked out or any too low calcium to build up again. It also depends on what other factors are in play that make the formation of stones more likely. In the longer term you will hopefully be successful. It's taken me some time to finesse for myself as I live in a rather high calcium/high mineral area but in the last 8 years I have only had one case with a larger stone, and that was in the wake of the fresh food supply shortages during the first Lockdown, when we were shielding and all that was to be found was on the higher calcium side...
Long Term Balanced General And Special Needs Guinea Pig Diets

I have never heard that spinach can be used to deal with bladder stones; it is generally rather high on our list of foods to only feed as a rare treat.