Oxalic Acid, What do you think

[Seiryu]

So this is not a thread on whether or not too much Oxalic Acid is bad. We all know too much is bad.

I however am curious as to what people think in terms of whether or not it's better to feed oxalic acid greens only a couple days a week in slightly larger quantities or feeding it 4-7 days a week, but very small quantities.

So here's the example.

What are your thoughts on:

1. Do you feed 3 grams of oxalic acid items 2 days a week

OR

2. Do you feed 1 gram of oxalic acid items 6 days a week.

This is of course purely an example, just so people can see what I am getting at. It's the exact same amount of oxalic acid in a week, but one is almost daily, whereas the other is 2 days a week.

I am trying to get at is, do YOU think it's better for the tortoise's body to only have it 2-3 days a week so it can "get rid of" the oxalic acid between the days of it not having any.

Or do you think as long as you are careful (and not over feed it), even if you fed it daily, that there would never be enough build up to cause problems.

I have always really wondered about this. I personally feed items with oxalic acid (mainly collard, dandelions) 5 or 6 days a week. But it's only maybe 10% of his food that day, and there are always days where he gets no food items with any.

 

[Tom]

I don't have your answer, but I've spent a fair amount of time looking in to this sort of thing over the years. There is nothing but conflicting, confusing info out there. I decided long ago to just feed everything in moderation and use a large variety of nutritious food items. So far this strategy has worked well for me, but I'm certainly open to learning new things if someone has been more successful or thorough in their research than me.

 

[Seiryu]

I don't have your answer, but I've spent a fair amount of time looking in to this sort of thing over the years. There is nothing but conflicting, confusing info out there. I decided long ago to just feed everything in moderation and use a large variety of nutritious food items. So far this strategy has worked well for me, but I'm certainly open to learning new things if someone has been more successful or thorough in their research than me.

Ya, I just play it safe and feed very low quantities of it. He loves collard, dandelion and clover, but it would still be nice to know whether or not they need some type of "days off" to cleanse themselves of the acid.

Some weeks I don't feed any for days in a row, but that's more rare. All my turnips, radishes and mustard's got eaten by the bunnies here , so I've had to resort to feeding them more daily, albeit in smaller quantities.

 

[RandomWiktor]

TBH, I often wonder just how dangerous oxalic acid ACTUALLY is to herbivores. Many wild weeds, grasses, and leafy greens have a decent ammount of the acid in it naturally. Wouldn't it make sense that herbivorous species may have evolved mechanisms to deal with the stuff reasonably well? I ponder this because many/most of the actual peer reviewed scientific research studies on oxalic acid that I've read have not been on say, iguanas, tortoises, or even deer, but on omnivores that don't naturally eat a high forage diet to begin with like mice and rats. Don't get me wrong, I'm not saying it's GOOD to feed a high oxalate diet to grazing animals; there's a heap of anectodotal evidence in the form of veterinary reports of herbivores fed imbalanced 100% spinach diets and the like. But I also think that as long as the animal's diet is highly varied, feeding the animal higher oxalate foods probably perfectly fine. I've always fed my herbivores a wide range, and even among species that often run into deficiencies and MBD in the captive environment (ie. green iguanas), I've had not a single issue.

---

 

[RandomWiktor]

I also think that as long as the animal's diet is highly varied, feeding the animal higher oxalate foods probably perfectly fine.

Couldn't edit, but to clarify, I meant feeding occasionally & in small quantities.

 

[tortoisenerd]

I don't think there is much research about this. I sure tried to find it. I just stick to having less than 50% of my tort's greens each day be those with oxalic acid, and avoiding the ones that are very high (like spinach and chard). I personally don't think it would make a difference to have off days or not as it has its effect over time. I know some people feed almost primarily collards, mustard, dandelions, etc and have no problems, but others who have torts with low oxaliac acid diets and their torts get stones...since I can't find the needed info I just try to keep the content low while still providing a varied diet (if I fed him no oxalic acid he'd only be able to eat lettuces pretty much). I buy spring mix all the time, and then 1-2 heads of other greens, most of which contain oxalic acid except turnip greens and kale (which I feed less of because of the goiter risk). I feed a bit more spring mix than the other greens, and then a bit of treat foods like Mazuri, cactus, and pumpkin. I am curious how that diet will be for him long term, but it seems rather typical for this forum.

 

[Madkins007]

I also wish the research was more clear on this topic, but...

I think the biggest concern is bladder stones, and most vets I have read consider HYDRATION to be the real issue here- as long as the tortoise is properly hydrated, the oxalates pass on out, but if it is dehydrated, it will concentrate them and other elements in the bladder and cause eventual problems.

Quite frankly, I've quit worrying about oxalates and worry more about hydration lately. I feed spinach as part of a rotation when I can get a good price, and do avoid the really heavy oxalate stuff, but then, most of that is more expensive than the stuff I usually buy anyway.

 

[tortoisenerd]

I have an issue that no matter what I try with hydration, my tort ends up having gritty urates (although they are only once every two weeks or so). I will soak every other day, wet the greens, etc. So, from what I have been told, gritty urates equals dehydration and thus I worry about bladder stones. What do you do to ensure your torts are hydrated, Mark? Thanks for the info!

 

[Tom]

I think Mark's advice is the way to go here. I've upped my soaking schedual since I first saw Mark post this info several months ago.

I figure if they get more water than they need, they'll just pee it out. Its when they don't get enough that you could run in to trouble.

 

[stells]

I don't feed anything high in Oxalic acid... due to a welll hydrated tortoise of mine forming a stone... i saw her drink all the time and she was soaked regularly... keep in mind Mark keeps Redfoots a species that can tolerate more... and that don't pass urates...

Neither hydration or Oxalic acid should be ruled out... both play just an important part as the other...

 

[GBtortoises]

I have never been concerned about oxalic acid in greens at all. In fact if you look at most plant contents, they all contain some level of oxalic acid. Many of the generally recommended foods for tortoises contain rather high levels of oxalic acid. Many of those same foods also contain high amounts of very beneficial vitamins and minerals which should not be overlooked.

I completely agree with Mark (Madkins007) above. What many people have neglected to do until recently with tortoises is put an important emphasis on hydration. The more hydrated they are, the more they are able to pass wastes, both urine and feces. With expelling wastes they are also expelling unwanted, unused, unneeded "materials" (for lack of a better word).

When they are not well hydrated a tortoise's natural defense is to store urine and wastes to keep from dehydrating. In that situation those unwanted and toxic materials are now building up rather than being flushed from their system on a regular basis like they should be.

 

[Madkins007]

I have an issue that no matter what I try with hydration, my tort ends up having gritty urates (although they are only once every two weeks or so). I will soak every other day, wet the greens, etc. So, from what I have been told, gritty urates equals dehydration and thus I worry about bladder stones. What do you do to ensure your torts are hydrated, Mark? Thanks for the info!

First, measure and weigh your torts so you KNOW if they are hydrated. Use the Donoghue Ratio- length in centimeters cubed, times 0.191 gives the minimum expected weight in grams.

If you use inches instead, multiply by 0.133 instead of .191 for an answer in ounces.

Fighting dehydration can take a lot of work-
- background humidity
- clean, accessible fresh water
- moist food, or very fresh food, etc.
- soaks (maybe)
- spritzing, wetting the animal directly
- offering wet bread occasionally
- well-planted area to walk in
- chances for exercise
- proper heat control (not too hot)
- humid hide option

 

[tortoisenerd]

Why the occasional wet bread? That doesn't sound right. Thanks for the other tips though.

 

[stells]

How does chances of exercise help with the hydration of a tortoise?

The bread thing... i know where this theory came from... the lady that does this didn't recommend to do it with all tortoises and only does it herself with her redfoots.. and she has some very bizarre ideas. Personally i can't see how it works... have you seen how much water a slice of bread can hold... it acts like a sponge and just keeps soaking it up... whats to say that it won't carry on doing this once inside the tortoise... after looking at what a loaf of bread contains... i would rather feed a soaked formulated diet rather than a slice of bread occasionally...

People also keep saying about proper heat control... but nobody can come up with a definitive answer...

My tortoise that passed the stone two years ago now... is now only just coming back to how she should be... she hasn't passed anymore stones but it did have a detrimental effect on how she functioned for quite some time... this is a tortoise that was soaked regularly... had access to water 24/7 was fed wet food... was sprayed down and that had outside time and well planted areas... hydration wasn't the problem with her... and i sound so sure about this as i have had no problems with any of my tortoises since researching their diet further...

This tortoise was also passing perfectly smooth urates right up until she passed the stone... you would have thought i was safe.... right?

 

[tortoisenerd]

Kelly-Sounds like it was more of a fluke and the tort was pre-dispositioned for it? My tort passed a stone just after I got him and I sure hope we don't have any future problems. No further symptoms so I haven't gone for an x-ray. Thank you for sharing and for the info on the bread--I agree.

 

[Angi]

Now I have something new to worry about I feed some spring mix, but mostly weeds, leafs and flowers I pick. How do I know if something is high in Oxalic Acid? I see this word used a lot, but really don't know what it is.

 

[Madkins007]

Rationales- which are admittedly mostly theory...

1. Opportunity for exercise. In theory, a moving tort is a thirsty tort. Movement also makes all systems work better and pretty much also means a variety of habitats.

2. Heat. Baking a tortoise, as we often do with our high temps/low humidty set-ups, is very dehydrating. One of the first signs of dehydration in many species is lack of thirst.

3. Wet bread. Lots of water, some nutrients. Occasional bread in the diet seems to help combat protozoa, although I cannot find where I read that. Comparing bread to tort chow is fair- very similar ingredients, but bread is cheaper, holds more water, and has less sugars in it. No one, as far as I know, recommends it very often. I toss in a soaked heal of a loaf once every couple months at the most when I am not using pellets.

4. Well-planted area should simulate dew, humid hides, live plants, etc. Rubbing against wet surfaces should help reduce water loss and increase humidity. Some video in "Life in Cold Blood" shows tortoises hiding in shrubbery when temps climbed, then foraging and mating in the open as temps drop a bit.




My THEORY is that we should combat dehydration on several levels-
- airway and lungs with proper humidity (balancing moisture loss during respiration, etc.)
- stomach with drinking water and moist foods
- intestines with foods with well-hydrated cells that release the water more slowly. Once a plant is cut, this form of water is lost rapidly, and I often wonder if it isn't a big part of the dehydration issue?

 

[tortoisenerd]

You can look up the oxalic acid content of foods online like at:
http://www.turtlestuff.com/avoidthese.html
http://www.nal.usda.gov/fnic/foodcomp/search/

In short, the lettuces in spring mix are all very low except if it has spinach (I would never feed), red chard (I would feed limited amounts, depends on how much comes in your spring mix if any), and mizuna (I feed all of this as it is less common in the spring mix and awesome for variety as you don't find it anywhere else in the supermarket). Weeds and greens like mustard/collard/radish/dandelion are higher. Turnip greens are low. Flowers are low. That said, you will find VERY conflicting reports on what is higher than others. I have seen something that says a food is low and another that says it is high (I like to use spinach as a baseline as I know I want to keep it well below that). It's very tough and I know I don't even have a grasp on it yet, so don't feel bad!

Mark-I think for newbies there is a big difference between a heel of a loaf (one piece I assume?) every few months between what I assume is a group of torts, and bread occasionally. Thank you for the elaboration. I still don't agree with that, but wouldn't argue with it due to the small quantity and frequency. The pellets I would feed are more hay based than bread based.

 

[chadk]

I feed spinach all the time. Just in low amounts. There are lots of good things about spinach.

 

[Maggie Cummings]

I keep Bob in a way that is against all 'rules'. His area is heavily planted in white and red (crimson) clovers. His shed is not humid, altho I live in an area of Oregon that freakin rains constantly so I'm hoping that makes enough humidity for him. He really does not drink enough so I am expecting a bladder stone. He pushed out about a handful of gritty rocky urates about once a month. His pen has an available water pool. There is a water bowl in his shed and this whole subject is something I worry about. All winter when graze is not available to him I feed low in oxalic stuff. But spring and summer his pen is about half clover and that's what he heads for to eat first. He grazes in the rain so that's a water source, I see him drink from his dish, and the pool of water so I know he drinks. But what is enough? His urates are awful and never the creamy they should be. Now they are high in grit or clear...go figure that one. But I try to make sure his diet is varied due to all the clover he eats. Only time will tell I guess...