If you have a cat and you have seen your cat eat any part of a daylily may I please ask you to answer a few questions at http://www.surveymonkey.com/s/...
It is important that as many people as is possible provide information. No personal questions are asked. I will post the results here when the information has been analyzed.
Thank you,
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Edited to add the results....
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The Results

There were 12 responses. That is good, but I will be posting similar survey requests at other daylily sites because I will need more responses to be convincing.
All identified plant B as the one their cat ate. Eleven identified that plant as a daylily and one identified it as not a daylily.
The cats ate seedling leaves (9), mature leaves (8), flower buds (1), flower parts (3) and even the fibrous roots (1).
Two of the cats vomited but the other 10 were completely unaffected.
None of the cats needed treatment.

What the ASPCA did and found:

The ASPCA veterinarians published an article with the title "A Retrospective Study of Daylily Toxicosis in Cats" . It was based on 22 reports in their database of cats suspected or known to have eaten daylilies. Of those 22 cats seventeen cats vomited (had upset digestive symptoms). Eight of the cats showed more serious problems. Of those showing more serious problems seven developed kidney (renal) failure. Of those seven it was known that five died even though treated.

The problem:

The ASPCA report is basically the opposite of what daylily enthusiasts have observed happen to their cats when they have eaten daylilies.

Lilium, true lilies such as the Easter lily are known to be poisonous to cats and cause kidney failure.

Some people call Lilium, lilies and some call them day lily (or daylily).

Some people call Hemerocallis (true daylilies) daylilies and some call them lilies.

Some garden plant outlets sell daylilies as 'bulbs'.

It is unknown how the ASPCA identified that the cats which they classified as having eaten daylilies actually had eaten Hemerocallis. If they simply asked the cat owner there may well have been misidentifications in which some cats which ate Lilium were identified as having eaten daylilies. Those could have been the cats that developed severe symptoms and died.

The other side of the problem:

Hemerocallis (daylilies) are known to contain a poison. The poison has been identified and it has been found in the roots. Hemerocallis roots have poisoned and killed some people in Asia.

Many (most) chemicals are poisons. It is the amount eaten (the dose) that is used to decide how poisonous a substance is. Different individual plants can contain different amounts of their chemicals, including having none at certain times or when grown in certain locations or under certain conditions. The result is that daylily roots have been used medicinally in Asia for a long time with very few cases of human poisonings.

It is easy to understand why the ASPCA takes the cautious approach and labels Hemerocallis as poisonous to cats. Cats actually correctly identified as having eaten Hemerocallis may be aggressively treated by vets even if they show no symptoms. Their concern is that if not treated then, the cat may later show symptoms and by that time it is too late.

Modern taxonomy does not place Hemerocallis in the same plant family as Lilium (the family Liliaceae) it does not even place them in the same plant order (the order Liliales), but that is very recent and such changes can take a very long time before they are generally accepted as correct.

I will post requests for daylily growers to complete a survey at three other locations. Hopefully I will be able to collect at least 40 completed surveys in total, which would be about double the number analyzed by the ASPCA. That may help convince them to try some properly controlled feeding tests of their own (as long as all the surveys do indicate that eating daylilies never poisons cats).

A final request, if you completed the survey and you have seen more than one cat eat daylilies, could you please post in this thread how many cats you have seen eating daylilies. Thank you.

Maurice

Maurice - I sure wish we could get the daylily off the list of problem plants for cats. My own vet knows better, yet just sent out a link to clients that listed daylilies on the poisonous list.

I filled out your survey.

Thanks for doing this!

I always heard it's only the Asiatic lilies that are poisonous to cats, as they can cause kidney damage and possible failure. I have six cats and I've never seen any of them chewing on any daylilies. But they do love the grass family!

Maurice, just completed the survey and hope it helps establish clearly either that daylilies are--- or are not--- toxic to cats.

Just like Betty we've never seen our cats eating dls, or the neighbors cats that come through our yard. To be fair though I didn't realize there was a possibility of dls hurting cats until last year, so probably haven't been really watching for it. Look forward to reading your results.

The ASPCA keeps a database on plants toxic to pets/animals, and does indicate that Hemerocallis is toxic to cats (liver failure, which can be fatal) and cows, and not toxic to dogs. But, the same entry claims the Family for hemerocallis is the lily family "Liliaceae" which is not correct. Betty must be right that it is just Asiatic lilies that are toxic to cats. Unfortunately, it looks like the Animal Poison Control Center/ASPCA has it confused and mixed together - since lilies and daylilies are not from the same family at all, as it would appear from their "Day-Lilies" entry.

http://www.aspca.org/Pet-care/...

Perhaps this is one source of confusion that vets and owners find who reference that site, or others who disseminate their information to base alerts upon? Once the survey results are known, it might be a good place to contact and update.

I did the survey. We have had more cats than I care to know for many years inside and out. I have never noticed an outside cat eating any part of the daylilies, only grass. We have a cat inside who munches on the daylily foliage when new ones are soaking in the kitchen sink. She has not been sick nor has she thrown up from eating the foliage. Of course, she has a condition known as P.I.C.A and eats clothes, towels, socks, shoe strings, etc. That may kill her one day but it won't be from eating daylily foliage.

Doris

Took the survey. I have many many kitties. The only danger from eating daylilies is the danger from their daylily obsessed owner!

Took the survey too. I think what Tina said is probably what happens. I've read hysterical owners with this same question on other daylily forums. They believed that daylilies were deadly because their vet told them they were. The list needs to change and Vets need to be notified. I have one cat that I've seen eating daylily foliage. That was maybe 4 or 5 years ago. She's still with me......Maryl

Even though I usually keep the door closed when I have seedlings in a small bedroom, occasionally the cats do manage to get in there and chew some. No problems, have never seen anything. It also saves me from having to trim them.....

So I too took the survey. Hope this helps for better identification of poisonous plants in the future, and that it quits giving daylilies a bad rep ~Jan

Done.

If you are a member of the daylily robin (AHS), search the archives as it has been discussed several times.

Maurice updated the first post in this thread, and asked me to change the title to reflect the results of his survey.

I have had many cats eat foliage. I gave up on trying to start seeds indoors as my house cats always find a way to get to them and chow down all the tiny seedling foliage to nubs and have never been sick from it. My outdoor cats eat the seedling foliage too - but they also eat grass and chew on other young greenery of other plants. In the summer, they hang out under the daylily foliage, and are often seen chewing on the over hanging foliage tips. I've seen several of my indoor cats that managed to get up on my tables and get to various flowers I have brought inside and chew on the petals - daylilies included. I've never had any become ill to the point of being concerned about them, having them vomit or taking them to the vet. However, the outdoor garden cats might become sick and vomit and I don't know about it - but I don't think it is a problem for them.

The fact that daylily roots are poisonous to humans is surprising to me. Don't the Chinese eat daylilies as part of their diet??? I know I have tried the tubers and boiled them like potatoes just out of curiosity and I didn't get sick.

Hemlady said:The fact that daylily roots are poisonous to humans is surprising to me. Don't the Chinese eat daylilies as part of their diet??? I know I have tried the tubers and boiled them like potatoes just out of curiosity and I didn't get sick.

The Chinese have used the roots for herbal medicines. At least some Chinese researchers are investigating how to make daylilies safer or looking for medicinal replacements that are safe. They do use flowers and/or dried buds as food items.

Poisons are very complicated.

If I asked people to choose whether to drink a cup of caffeine or a cup of trichloroethylene (an industrial solvent) most people would say the cup of caffeine. Unfortunately, caffeine is more poisonous than trichloroethylene. It takes 2.4 g/kg body weight of trichloroethylene to kill 50% of the mice it is fed to but only 0.1 g/kg of caffeine to kill the same proportion of mice.

Some of us drink many cups of coffee, or tea or colas each day. Of course a cup of coffee is not the same as a cup of caffeine. A cup of coffee might have 0.1 g of caffeine. And a person might weigh 70 kg. A person would have to drink 70 cups of coffee in one go to get the dose of caffeine that would kill 50% of the mice. (People might have a different dose that kills 50%, for example the dose that kills 50% of lab rats is 0.2 g/kg body weight).

Second, there is more than one daylily species. The poison has been found in some of the daylily species but it may not be in all of them. Unfortunately, our daylilies were originally created using hybrids of quite a few daylily species. So some daylily cultivars might have the poison and some might not.

The poison might not be in the roots until certain times of the year or it might not be in the roots unless the daylilies have been stressed by heat and no one knows whether the poison is present only some of the time and what might cause it to be present or absent. It is not known what might cause differences in the amount of the chemical in the roots. How many roots would have to be eaten to become ill is also unknown.

Boiling plant parts removes some chemicals - at least some of them dissolve into the water. There are wild plants that can be collected and eaten. The instructions often say to cook the plants in several changes of water to remove/reduce chemicals that might make one sick. Whether the poison in daylily roots is removed by boiling the roots or whether the poison is destroyed by heat is unknown.

I'm very glad that you suffered no ill effects from eating the boiled tubers. I have eaten the flowers once. But I have never done so again after I learned that more than one research group had found poison in the roots and that some people had died. I would never eat any of the tuberous roots.

The poison was first named hemerocallin but is now called stypandrol.

Maurice,

I have 17 cats today and have had many many over the years. I can say that I can recall 5 of them specifically eating my daylily leaves. None of those 5 had any issues. Hope this helps.

Is the full text for the retrospective study available anywhere online for free?

Thanks for that info Admmad. Gosh, and I thought if we ever had a food shortage in this country that I would still have my daylilies to eat Guess not.

Anne said:Is the full text for the retrospective study available anywhere online for free?

Not that I know of. You may be able to request a copy through InterLibrary Loans through your local public library. I do not know what the cost of a photocopy would be.

The full information for requesting a photocopy is:

Title: A Retrospective Study of Daylily Toxicosis in Cats

Authors: RM Hadley, JA Richardson, and SM Gwaltney-Brant

Journal: Vet. Human Toxicol. Volume 45 Issue 1 pages 38-39, 2003

This has been a GREAT thread, such great information.

The problem with vomiting after a cat eats daylily leaves is that many cats will vomit after eating something like that. I know my cats will vomit after eating grass - and the grass isn't poisonous - I always believed that they ate grass because they had an upset stomach, and did so to make themself vomit (or is that an old wive's tale?)

I know at least one of my cats ate my seedlings, I don't remember if he vomited. (he has since passed away several years later of bladder cancer) That was the cat I was referring to when I completed the survey. ~Jan

I believe cats eat grass when they are trying to get rid of a hair ball in their stomach. They know that grass will make them vomit. My cat if he can't have grass will deliberately swallow his dry food whole and that makes him vomit too.