DAN: "What plants are toxic to horses?"
So I know in the past, we've done videos
about what fruits and vegetables--
DR LYDIA GRAY: Right.
DAN: --which, we'll put a link in the description for you guys
so you can check that one out.
So I am curious to see what plants are.
DR LYDIA GRAY: Oh, so the short answer
is pretty much everything.
There's hundreds.
And this book is quite old.
It's Horse Owner's Field Guide to Toxic Plants.
But--
DAN: The name says it all.
DR LYDIA GRAY: Yeah, it's a wonderful book.
I think I got it in either undergrad or vet school.
And I use it even now.
So it's quite old.
And there's also-- so the author, Sandra Burger,
used a resource.
His name is Anthony Knight.
And he's recognized as one of the gurus of toxic plants
in animals, especially horses.
So great resource.
And he has written or been interviewed
for many articles in magazines.
And I picked one in Equus a couple of years ago
where he listed the 10 most poisonous plants for horses.
DAN: OK.
DR LYDIA GRAY: OK, so I want to read through that.
And those are the ones to keep an eye on mostly.
So bracken fern-- and I can add some tips
about each, like must consume hundreds of pounds of it, which
normally wouldn't be a problem except this
is one of the few poisonous plants that horses find tasty.
DAN: Ah.
Why is that?
Why does nature do that?
DR LYDIA GRAY: It's not fair.
So number two is poison hemlock, where four to five pounds is
a lethal dose for a horse, and then tansy ragwort,
also known as groundsel.
It's, again, in the 50 to 150 pounds, but it's cumulative.
DAN: So they would have to be out in that area for a while.
DR LYDIA GRAY: Over time.
DAN: Over time consuming that.
DR LYDIA GRAY: Yeah.
Something in my area--
Johnsongrass or sudangrass.
It's a sorghum variety, but only when it's damaged,
wilted, trampled, frost.
DAN: OK.
DR LYDIA GRAY: Yeah.
Like-- like the red maple leaves, which is on here too.
Only a pound or two of those can be toxic,
but it has to be wilted leaves.
So in the fall when the leaves drop or after a storm.
DAN: So that's when they're the most toxic.
DR LYDIA GRAY: Yeah.
Leaves-- red maple leaves on the tree aren't toxic.
It's after they're--
DAN: Wilted and--
DR LYDIA GRAY: Wilted, yeah.
Locoweed, oleander-- now that's an ornamental.
DAN: Yeah.
DR LYDIA GRAY: And it only takes 30 to 40 leaves.
Another ornamental, and this one they have a lot where I live,
is yew, Japanese yew.
DAN: OK.
DR LYDIA GRAY: It's a bush planted around houses.
And you're like, how do horses get access to that?
DAN: Yeah.
DR LYDIA GRAY: Well, what happens
is-- and here, it's only a handful.
Only a few leaves can kill a horse.
When people or landscapers trim the bushes and they're like,
oh, horses and they throw it over the fence, the clippings,
and then the horses eat them.
That's--
DAN: They think they're doing something good every time.
DR LYDIA GRAY: Yeah, that's how it happens.
So you've got to be careful.
Water hemlock is on there, and yellow starthistle,
which is also known as Russian knapweed.
So those are my list of 10.
DAN: Is there something people can
do to find out if they have these things on their property?
Because I'm a super hypochondriac.
So now you've told me this.
I will assume everything in the area is now toxic.
DR LYDIA GRAY: So I wrote also an article.
Could you hold this one?
DAN: I absolutely can.
DR LYDIA GRAY: Yeah.
It's a really good article in Dressage Today.
And what's the date on it?
Can we see the month and year?
DAN: 2016-- March 15, 2016.
DR LYDIA GRAY: OK.
So this is the issue you want.
And the article mentions things about who
to contact in your area about the poisonous plants.
Because poisonous plants, like all plants,
they don't grow-- most of them-- throughout the US.
There are areas, like the dry southern southwest US
or in the cold northern climates.
Or maybe a plant only grows in Florida or something.
So talk to your veterinarian.
And if he or she doesn't have the resources right there, what
you'll do is work with your local vet school or university.
And the county extension agents are a great resource.
They know exactly what plants are
in your area what to watch for.
DAN: So you can see if anything matches up
to what's on that list.
And then if you have it--
DR LYDIA GRAY: Yeah.
The other tip is because most poisonous plants aren't
very palatable, horses avoid them
except when they're hungry.
DAN: And then they'll eat anything.
DR LYDIA GRAY: Well, yeah.
So when I was in practice, every July, August--
so every summer, fall--
we'd have an outbreak of white snakeroot poisoning
because pastures would dry up or horses would eat them down.
And then they were hungry.
So they would-- this plant is found on the edge
of a pasture or the woods.
They would go further and find the only growing plant,
which was white snakeroot, which ordinarily, they wouldn't eat.
But they were hungry.
DAN: Yeah.
DR LYDIA GRAY: So if you can keep your pastures
in good shape and your hay in front--
when pastures are not looking good, then supplement with hay.
DAN: Mmm.
DR LYDIA GRAY: So keep your horses full.
DAN: So then they're not--
DR LYDIA GRAY: --seek out--
DAN: --those other--
DR LYDIA GRAY: --things they normally wouldn't eat.
So-- but the other thing I wanted
to tell you-- so we got the important stuff out of the way.
DAN: Yes.
DR LYDIA GRAY: 10 most poisonous plants and a few tips.
My husband is a veterinarian, too.
DAN: Mm-hm.
DR LYDIA GRAY: You knew that, right?
DAN: Yes.
DR LYDIA GRAY: And he's a small animal vet.
And he's interested in snakes and toads and frogs
and amphibians.
So he's what's called a veterinary herpetologist.
DAN: Yeah, you guys have a couple snakes, right?
DR LYDIA GRAY: We do.
We do.
So every once in a while, someone
asks us, "Are your snakes poisonous," right?
DAN: Uh-huh.
First question to come out of my mouth.
DR LYDIA GRAY: And he reminds me that snakes are not poisonous.
Snakes are venomous.
DAN: Ah.
DR LYDIA GRAY: Do you know the difference?
DAN: I do not.
DR LYDIA GRAY: I did not either, and I forget.
And so I am reminded by him every year.
So poisons are toxic substances secreted by plants or animals.
DAN: Mm-hm.
DR LYDIA GRAY: Like, there are those poisonous dart frogs
of somewhere, Brazil or something.
OK, venom is injected.
DAN: Ah.
DR LYDIA GRAY: So you have to be bitten.
So there's a little--
if you bite it and die, it's poisonous.
DAN: If you bite it and die, it's poisonous.
DR LYDIA GRAY: If it bites you and you die, it's venomous.
So there you go.
DAN: That's the fun tip fact for today.
DR LYDIA GRAY: Yep, yep.
DAN: That's a good way to remember it.
DR LYDIA GRAY: You need that, who knows, tomorrow.
DAN: Hopefully not.