How many tortoises get seriously ill or die as a result of eating "bad" weeds?

[RosemaryDW]

We are very strict about telling new owners to avoid feeding absolutely anything they don't know is safe. Is that overkill?

I know tortoises absolutely suffer as the result of poor diets (like all iceburg or tomatoes!) but how many weed or yard plant poisoning cases have we seen? I know there is one thread on a sulcata getting a bad reaction from eating a load of tulip bulbs but are there others? Has there been a case of death by oxalis, for example?

The safe weeds list we provide new owners is a great place to get them started but it is limited. We direct new owners to the Tortoise Table but in my opinion, its logic often doesn't make sense and it's overly conservative. I don't rely on it.

After reading our advice, many owners are terrified to feed the wrong weed but are the dangers well documented? Maybe for sulcatas but what about other types? Would it really be so bad for owners to let their tortoises take a nibble of something unknown while they get used to identifying what's around them? Would that be better or worse than having them stick with a bag of spring mix for extended periods of time?

 

[Yvonne G]

I have no idea the answer to the question, but I've heard that spurge and oxalis, both high in oxalates, are part of the desert tortoise's regular diet.

 

[Tom]

This is a good question. I'll share my thoughts on the matter: The reptile vets that I am privileged to call friends here in SoCal see several cases a year of this. Given the thousands upon thousands of tortoise keepers that are in this area, I would grant you that death by eating poisonous plants is not all that common, but it is common enough for me to want to warm others to use caution. We have several members here who claim that tortoises have survived for millions of years without our help and they know what to eat. I counter with: That is fine for a hatchling that grew up in its own native environment in the wild with indigenous plants, but the whole idea goes out the window when we move them to a different continent with difference weeds and plants that are from all over the world. I realize that some tortoises choose not to eat some poisonous plants some of the time, but I'm not going to gamble with my tortoises life, or anyone else's tortoises life that way. I've seen too many die.

I also counter that incorrect notion with case after case of dead tortoises. Just last year during a visit with one of my vet friends I had to help him move a dying 300+ pound aldabra. Its galapagos yard-mate had already died. It seems that the man's gardeners decided to add some new plants to the margins of the yard without asking him. They planted some jasmine and the two giant tortoise started eating the new plants as soon as the workers walked away after planting them. The aldabra died a few days after I saw it. So sad. So preventable.

 

[Tom]

Has there been a case of death by oxalis, for example?

Oxalis is not toxic. It is high in oxalates, which over time, with enough consumed, can affect calcium absorption and utilization.

I used to feed small amounts of it to my tortoises on purpose back when I mistakenly thought it was some sort of safe clover. They can eat some of it, they just shouldn't eat lots of it on a regular basis.

Things like oleander, azaleas, jasmine or other toxic plants are a different story.

 

[Markw84]

Oxalis is not toxic. It is high in oxalates, which over time, with enough consumed, can affect calcium absorption and utilization.
.

Is that really true? I don't know and am becoming more and more weighted towards the idea that tortoises are totally different in the way their metabolism treats many items we consider "bad". Another thread going on now was on reducing oxalates and here's a small part of my post...

I was interested because We do hear so much about eliminating dietary oxalic acid and how bad oxalates are, but more and more I don't see why. You, Will are far more of an expert on this than I am, hence my interest. Especially with my recent experience with my sulcatas. I was concerned they were eating so much oxalis, and all I heard was that it was really bad and to be avoided because of its high concentrations of oxalic acid. This thread seemed to directly speak to the binding of calcium with oxalates leaving much less "bioavailable". Because I watched my sulcatas consuming large quantities, and, in particular, by laying female, it was forefront in my mind. She laid her first clutch in March. As a young female she also has been laying eggs with thin shells and many eggs break easily as she lays. I am trying to particularly enhance available calcium for her. The first clutch had several broken shells. Her second clutch was the beginning of May right after the oxalis started taking over in the enclosure. So maybe a week or so of eating oxalis rich grazing. That clutch was even worse despite the Mazuri and cuttlebones. By mid May there was far more oxalis than grass. I though she was done laying eggs and wasn't as attentive to pushing calcium, but was still concerned about the oxalis for overall health. She laid again mid June. So those eggs were forming shells while she was grazing on heavy oxalis content. Her last clutch was the best she's ever laid. Nice thick shells, absolutely no broken eggs!!

When I had an opportunity to speak with the two main vets and the horticulturist for the Behler Center, in noting almost all their greenhouse enclosures had pothos ivy growing everywhere, I asked about why it is listed as harmful with all the oxalic acid and calcium oxalates (raphides). Their response was it is a non-issue with chelonians. Dogs and cats are bothered and get irritations from the raphides, but chelonians are not affected. They were not concerned about the oxalic acid and it was freely available for any grazing of most all their tortoise species.

There is so little known about chelonian diet and metabolism. I think we will find a lot of the cautionary items will turn out to be entirely different in the case of chelonians vs. mammals.

I guess in the meantime, caution is warranted as there are some indeed that are toxic. I am starting to pay more attention to the ingredient that is causing the warning, though.

 

[stevenf625]

is English Ivy supposed to be toxic in the same way as you thought Pothos Ivy is.
This is a current worry of mine as Rhialto ate something similar 2 days ago and does not seem as active as usual.

 

[Tom]

Is that really true? I don't know and am becoming more and more weighted towards the idea that tortoises are totally different in the way their metabolism treats many items we consider "bad". Another thread going on now was on reducing oxalates and here's a small part of my post...

I was interested because We do hear so much about eliminating dietary oxalic acid and how bad oxalates are, but more and more I don't see why. You, Will are far more of an expert on this than I am, hence my interest. Especially with my recent experience with my sulcatas. I was concerned they were eating so much oxalis, and all I heard was that it was really bad and to be avoided because of its high concentrations of oxalic acid. This thread seemed to directly speak to the binding of calcium with oxalates leaving much less "bioavailable". Because I watched my sulcatas consuming large quantities, and, in particular, by laying female, it was forefront in my mind. She laid her first clutch in March. As a young female she also has been laying eggs with thin shells and many eggs break easily as she lays. I am trying to particularly enhance available calcium for her. The first clutch had several broken shells. Her second clutch was the beginning of May right after the oxalis started taking over in the enclosure. So maybe a week or so of eating oxalis rich grazing. That clutch was even worse despite the Mazuri and cuttlebones. By mid May there was far more oxalis than grass. I though she was done laying eggs and wasn't as attentive to pushing calcium, but was still concerned about the oxalis for overall health. She laid again mid June. So those eggs were forming shells while she was grazing on heavy oxalis content. Her last clutch was the best she's ever laid. Nice thick shells, absolutely no broken eggs!!

When I had an opportunity to speak with the two main vets and the horticulturist for the Behler Center, in noting almost all their greenhouse enclosures had pothos ivy growing everywhere, I asked about why it is listed as harmful with all the oxalic acid and calcium oxalates (raphides). Their response was it is a non-issue with chelonians. Dogs and cats are bothered and get irritations from the raphides, but chelonians are not affected. They were not concerned about the oxalic acid and it was freely available for any grazing of most all their tortoise species.

There is so little known about chelonian diet and metabolism. I think we will find a lot of the cautionary items will turn out to be entirely different in the case of chelonians vs. mammals.

I guess in the meantime, caution is warranted as there are some indeed that are toxic. I am starting to pay more attention to the ingredient that is causing the warning, though.

Good points as usual Mark. In the case of oxalis, I am guilty of parroting what I've read and heard. In the years that I was feeding handfuls of oxalis to my adult sulcatas (For everyone reading, I would grab a big handful and mix it all up with other weeds, grass and grass hay. We are talking maybe a ratio of 5% oxalis to all the other stuff.), I never observed any problems. My females were not laying eggs yet at that time.

I too had a couple of females laying thin shelled eggs for a couple of clutches, and over time the problem also went away for me. I started adding powdered calcium to more of those female's meals, but I can't say for sure if that did or didn't have anything to do with the improvement.

 

[Kapidolo Farms]

If "THEY" don't know it's safe, they should not feed it. Tom's narrative about some tortoises eating Jasmine is the good example. They did not know, they lost their tortoise.

Actively knowing something is good or bad is means to an end, that end being safe feeding. There are many resources for THEM to learn. TFO is one of those resources. The Tortoise Table is another. To error on the side of caution (the precautionary principle) is almost always going to yield neutral or positive results. Spending time finding out, is the route to take.

I use many other resources than here on TFO and The Tortoise Table. Visually looking to see what is in the grocery store is one good way. Looking at Feedipedia.org, the FAO also has much to say about both common and uncommon potential diet items. Natural history observation (sorta rare for diet items, but still a resource) is a good one too.

I do not like the alarmist nature of some posts regarding diet items and their impact. It's not so difficult to find some resource that indicates where on the range of quality something may be, from death in seconds, to unbounded growth and reproduction.

Many of the substances in plant tissue that are toxic are plant stress related. They occur during drought, when some fruiting body is developing, or some other factor. Those same plants and parts can also be high quality food at other times. I think this is the indigenous "knowledge" that tortoises can work with. I have no 'research' reason to believe that tortoises try things out in small amounts and wait for some kind of feedback via "how they feel" from eating something. But I believe that is the trait that both helps the wild tortoise and kills the long term captive tortoise.

I tried this out one time, the tortoise was very acclimated to eating from peoples' hands. I offered an onion to it, it took a big bite, was about to go for a additional bite and then realized something was wrong. It spit out the first bite. I then offered an apple and it went for it right away. They become patterned into behaviors, including food sensibility.

Also, there is no knowing how many tortoises perish in the wild from eating the wrong thing to the extent that that is a cause of death.

So, none hysterical caution is good. Overkill is only in the hysteria, not rational caution.

 

[Markw84]

If "THEY" don't know it's safe, they should not feed it. Tom's narrative about some tortoises eating Jasmine is the good example. They did not know, they lost their tortoise.

I have no 'research' reason to believe that tortoises try things out in small amounts and wait for some kind of feedback via "how they feel" from eating something. But I believe that is the trait that both helps the wild tortoise and kills the long term captive tortoise.

My belief on this is in the wild some tortoises eat poisonous items and they die. They do not pass on those preferences or proclivity. Other tortoises do not have a "taste for" that item and they live. They pass on that trait. Can't imagine they have any intelligence or reasoning to eat a small portion and know if that item got them sick or not!

I also like this reference from the California Poison Control System that I use and have the shortcut on my desktop. It gives me a better idea of why a particular plant is bad. Also seems to be the most comprehensive database I have found.

It still leaves us with the question of "does that apply to tortoises?' but that's the stuff for ongoing discussion, observation and research. As we do... I agree - err on the side of caution!

 

[Tom]

Many of the substances in plant tissue that are toxic are plant stress related. They occur during drought, when some fruiting body is developing, or some other factor. Those same plants and parts can also be high quality food at other times. I think this is the indigenous "knowledge" that tortoises can work with.

I think "fiddle neck" serves as a good example of this type of plant. Amsinckia intermedia.

https://csuvth.colostate.edu/poisonous_plants/Plants/Details/40

The above website lists it as toxic across the board, but other research indicates that the young budding spring plants are safe, and only the seeds and seed heads are toxic. I've fed this to my tortoises when the plant is small with no ill effect. As soon as I see a hint of a seed head, I pull it out by hand, root and all, and chuck it in the trash. Even in winter when this plant sprouts here, its never made up even 1% of their daily diet.

Also, there is no knowing how many tortoises perish in the wild from eating the wrong thing to the extent that that is a cause of death.

This is another excellent point I've pondered, but found no research one way or the other.

 

[Tom]

It still leaves us with the question of "does that apply to tortoises?' but that's the stuff for ongoing discussion, observation and research. As we do... I agree - err on the side of caution!

To this point, I use the logic: There are LOADS of other things to feed our tortoises. Why take risks with things we aren't sure of. My tortoises will not starve if they never eat oxalis or young fiddle neck plants. Why not just feed more mallow, dandelion, prickly lettuce, grass, opuntia, mulberry, hibiscus or grape leaves, etc…? Things we know are safe.

 

[stevenf625]

My belief on this is in the wild some tortoises eat poisonous items and they die. They do not pass on those preferences or proclivity. Other tortoises do not have a "taste for" that item and they live. They pass on that trait. Can't imagine they have any intelligence or reasoning to eat a small portion and know if that item got them sick or not!

I also like this reference from the California Poison Control System that I use and have the shortcut on my desktop. It gives me a better idea of why a particular plant is bad. Also seems to be the most comprehensive database I have found.

It still leaves us with the question of "does that apply to tortoises?' but that's the stuff for ongoing discussion, observation and research. As we do... I agree - err on the side of caution!

For the document you referred to: What does the rating system mean e.g., what does it mean that Boston Ivy is rated 2a, 2b?

edit
nevermind i see the explaination on page 61
2a= oxalate crystals
2b = more oxalate crystals
but neither appear fatal (at least to humans)

 

[Markw84]

For the document you referred to: What does the rating system mean e.g., what does it mean that Boston Ivy is rated 2a, 2b?

edit
nevermind i see the explaination on page 61
2a= oxalate crystals
2b = more oxalate crystals
but neither appear fatal (at least to humans)

So for me, I am not as concerned with 2a. But I would still exercise caution if listed as a 2b. But 2b is where I am with oxalis! Pothos Ivy is a 2a. Your Boston Ivy is both 2a and 2b.

 

[stevenf625]

So for me, I am not as concerned with 2a. But I would still exercise caution if listed as a 2b. But 2b is where I am with oxalis! Pothos Ivy is a 2a. Your Boston Ivy is both 2a and 2b.

I don't know what type of ivy it was. It has an English Ivy leaf shape, but without the viens. The leaves are flat green, almost look like a fake plant. I posted a picture in the Plant Identification section

 

[Kapidolo Farms]

My belief on this is in the wild some tortoises eat poisonous items and they die. They do not pass on those preferences or proclivity. Other tortoises do not have a "taste for" that item and they live. They pass on that trait. Can't imagine they have any intelligence or reasoning to eat a small portion and know if that item got them sick or not!

Some of us call that evolution. LOL They do pass it on, in that those urges or "taste for" get weeded out. Pretty good Pun there Huh?

 

[RosemaryDW]

To this point, I use the logic: There are LOADS of other things to feed our tortoises. Why take risks with things we aren't sure of. My tortoises will not starve if they never eat oxalis or young fiddle neck plants. Why not just feed more mallow, dandelion, prickly lettuce, grass, opuntia, mulberry, hibiscus or grape leaves, etc…? Things we know are safe.

Agreed. And agreed with Will that taking the time to learn is the best way. (I pretty much agree with everything posted by everyone, btw, it's all so well thought out.) So I'll go back to my first question, which was are we sending messages to new owners that are overkill?

We tell them in strong terms that weeds should constitute a large part of the diet whenever possible; we tell them weeds and safe foods are easy to find. We tell them in equally strong terms not to feed anything unknown; not to feed anything they are not absolutely certain has been sprayed. As their questions grow deeper, we start to tell them we actually don't know that much about plant toxicity in reptiles!

These are conflicting messages. How is a new owner, already told their housing is entirely wrong, their tortoise is not a baby, one is being bullied to death, etc., supposed to fully process all these feeding messages as well? It puts them in a no-win situation, at a vulnerable time in their ownership.

Owning only a single tortoise, I will never have deep experience with diet. I keep struggling to find the right away--in my mind--to support a new owner. At this time, I think the least wrong answer is, "Do the best you can for now and add in foods over time as you become more experienced." Right now the takeaway for many new owners is "You must get it all right, right now." That's not exactly what we say, but that's what they hear. Perhaps there is a better way to combine our messaging on diet.

*My* takeaway today is that I need to be more relaxed when new owners seem panicky about weeds. Not more relaxed about feeding random weeds, more relaxed about encouraging folks to slow down their pace and stick with safe foods early on, even if that means fairly limited foods. Even if it means spring mix.

 

[Tom]

Agreed. And agreed with Will that taking the time to learn is the best way. (I pretty much agree with everything posted by everyone, btw, it's all so well thought out.) So I'll go back to my first question, which was are we sending messages to new owners that are overkill?

We tell them in strong terms that weeds should constitute a large part of the diet whenever possible; we tell them weeds and safe foods are easy to find. We tell them in equally strong terms not to feed anything unknown; not to feed anything they are not absolutely certain has been sprayed. As their questions grow deeper, we start to tell them we actually don't know that much about plant toxicity in reptiles!

These are conflicting messages. How is a new owner, already told their housing is entirely wrong, their tortoise is not a baby, one is being bullied to death, etc., supposed to fully process all these feeding messages as well? It puts them in a no-win situation, at a vulnerable time in their ownership.

Owning only a single tortoise, I will never have deep experience with diet. I keep struggling to find the right away--in my mind--to support a new owner. At this time, I think the least wrong answer is, "Do the best you can for now and add in foods over time as you become more experienced." Right now the takeaway for many new owners is "You must get it all right, right now." That's not exactly what we say, but that's what they hear. Perhaps there is a better way to combine our messaging on diet.

*My* takeaway today is that I need to be more relaxed when new owners seem panicky about weeds. Not more relaxed about feeding random weeds, more relaxed about encouraging folks to slow down their pace and stick with safe foods early on, even if that means fairly limited foods. Even if it means spring mix.

I get your point here. It just seems to me like common sense though... We tell the new person to feed lots of weeds of the right type and its just seems obvious to me that they will need to spend some time learning to ID their local weeds and which ones to feed. Many times, I phrase it that way in fact. "You will need to invest some time learning about your local weeds and plants. You can post pics here, look on various websites, and find a knowledgable weed identifier at your local garden center. In time, you'll learn how to recognize the good ones and the bad ones, and your tortoise will thank you by living a long healthy life."

I don't see this as a no-win situation. They got bad pet store advice that will harm or kill their tortoise, and we give them the right info that will help them and keep their tortoise alive and healthy. Is it frustrating, overwhelming or discouraging? Sure it is. I can imagine them spending two hours in the pet store soaking in all the "expert" sounding advice and then spending hundreds of dollars to buy crappy or detrimental products. Imagine my frustration 30 years ago with no internet and few people who had any idea what they were talking about. NO ONE in the entire world could explain the pyramiding thing that we'd been living with for decades. If someone had come along in 1994 and said to me: "Your failing because of this this and this, and here is how to do it correctly…" I would literally have jumped for joy! Sure I would have been pissy about the bad info from the pet store "expert", but that would quickly fade as my new animal began to thrive in the correct conditions. We all had to learn these rings through trial and error. LOTS of error, and lots of animals that suffered and died due to ignorance. Having dozens of knowledgeable people to guide me at every step of the way with every question I could possibly come up with would have literally been a miracle back then. Man, I would have done anything to have a mentor like MarkW, YvonneG, Will, cdmay, or any of two dozen more of the members here on this forum. Holy cow! Type in a question and BOOM! Experience based, helpful, accurate answers in seconds or minutes! That is a win any way you look at it.

I guess this is all a matter of perception. I'm enjoying this topic and discussion. Please dispute and discuss any point you disagree with, or offer me more guidance from your POV. I'd love new ideas about how to better help people and their tortoises. That is my goal, after all, and my bluntness is not always helpful.

 

[Markw84]

@RosemaryDW I understand completely what you are saying. However, it is easy to lose sight of how far you have come in your understanding of these things. The more you learn, the more you realize you don't yet know!! I see you really delving into the plants and plant ID and where to pick up and try more and more farmer market type items. Your perspective is way beyond a new person's questions. Your interest to push the boundaries leads you to many questions almost every other tortoise keeper will not deal with!!

A newbie can come here and quickly get such a large list of good items to feed. All the variety they and their tortoise needs. As @Tom mentions, it may come with a recommendation to spend some time learning to identify enough basic staples to be able to rotate maybe a dozen good choices. Grass, hibiscus, grape leaves, mulberry leaves, petunias, pansies, opuntia, chicks and hens, dandelion, thistle, milk weed. Add some Mazuri and cuttlebone or egg shells and you've got it!

For those like you, and me and Tom and Will and Anyfoot, and so many others here, we will continue to push that envelope and broaden the scope of those "easy answers". For us, it will get confusing and at times controversial, and we can bounce those ideas off each other here, until yet another thing becomes an accepted standard. No need to confuse that process with the advice we offer. For that, we stay on the side of caution and stick to the "easy" suggestions.

 

[MichaelaW]

This is a good question. I'll share my thoughts on the matter: The reptile vets that I am privileged to call friends here in SoCal see several cases a year of this. Given the thousands upon thousands of tortoise keepers that are in this area, I would grant you that death by eating poisonous plants is not all that common, but it is common enough for me to want to warm others to use caution. We have several members here who claim that tortoises have survived for millions of years without our help and they know what to eat. I counter with: That is fine for a hatchling that grew up in its own native environment in the wild with indigenous plants, but the whole idea goes out the window when we move them to a different continent with difference weeds and plants that are from all over the world. I realize that some tortoises choose not to eat some poisonous plants some of the time, but I'm not going to gamble with my tortoises life, or anyone else's tortoises life that way. I've seen too many die.

I also counter that incorrect notion with case after case of dead tortoises. Just last year during a visit with one of my vet friends I had to help him move a dying 300+ pound aldabra. Its galapagos yard-mate had already died. It seems that the man's gardeners decided to add some new plants to the margins of the yard without asking him. They planted some jasmine and the two giant tortoise started eating the new plants as soon as the workers walked away after planting them. The aldabra died a few days after I saw it. So sad. So preventable.

I work as a vet tech so I've seen numerous interesting cases, one of which being a large Aldabra and Sulcata die after their owners fed them Nicotiana repanda (Fiddleleaf tobacco plant) from the nightshade family. Two of the other Aldabras nearly did not make it, but apparently they did not consume enough of the plant to be fatal.

 

[Tom]

I work as a vet tech so I've seen numerous interesting cases, one of which being a large Aldabra and Sulcata die after their owners fed them Nicotiana repanda (Fiddleleaf tobacco plant) from the nightshade family. Two of the other Aldabras nearly did not make it, but apparently they did not consume enough of the plant to be fatal.

Thank you for sharing this. I feel like people who know, work for, or are somehow involved with the vet world see a greater cross section of the problems that can occur, than your regular tortoise keeping hobbyist.