Transcript Chapter 13: Poisonous Plants

Poisonous Plants and Livestock
From Romeo and Juliet - act 5
Come bitter pilot, now at once run
on.The dashing rocks thy seasick
weary bark! Here’s to my love! O
true apothecary! Thy drugs are
quick. Thus with a kiss I die.
Basic Management
• Know poisonous plants and when they are
potentially dangerous
• Inspect pasture and destroy poisonous plant
before grazing
• Make sure animals are neither hungry or
thirsty when on pasture or consuming hay
that might have poisonous plants
Basic Management (cont.)
• Do not put animals on forage that is too
young in springtime
• Use proper grazing management
• Provide supplemental feed/water during
periods of low pasture availability
Types of poisons found in plants
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Alkaloids
Glycosides
Organic acids
Resins
Mineral poisoning
Photosensitizing substances
Others (alcohols, thiaminase, gossypol and
hydroquinone)
Alkaloids
• Complex compounds containing nitrogen
• Affect CNS
Glycosides
• Complex compounds in which a nonsugar
group is combined with a sugar, usually
glucose
• Cyanogenetick glycosides that produce
hydrocyanic acid (HCN) upon hydrolysis
• Hydrocyanic acid stops RBC from releasing
oxygen
• Die of oxygen starvation at the cellular level
Organic Acids
• Most Common:
– Oxalic and tannic acids
• Symptoms
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Dullness
Weakness
Incoordination
death
Resins or resinoids
• Heterogeneous group of complex
compounds differing in chemical structure
• Have similar affect on nervous and
muscular systems
Mineral Poisoning
• May be caused by secondarily through prior
deposition toxic minerals on plant surfaces
or from certain plants that have the ability
to take up toxic minerals from the soil and
incorporate them into plant tissue.
Photosensitizing substances
• Animals become sensitive to light
• Burning, swelling and eventual sloughing of
the skin over none-pigmented areas of the
body.
1. Herbaceous Plants
• Acknowledgement: images
Cornell University
Department of Animal Science
• http://www.ansci.cornell.edu/plants/
THIAMINASE: Bracken fern
Pteridium aquilinum
• Probably the largest (up to 6 feet) and most
common of the ferns in Ohio
• Many habitats (full sun, partial shade, woods, old
pastures, and thickets)
• Indicator of poor soil (other ferns like good soil)
• One of earliest ferns seen in spring or after a fire
and one the earliest to be killed by frost
• Can form large colonies
• Solutions: Good pasture management
Bracken fern
• Leaves and rhizomes are toxic
• Toxic in both fresh and dried form
• Most common poisoning when other
grazing scarce (e.g. drought) or a
contaminant of hay
• Horses, cattle, sheep and swine
Bracken fern: Symptoms
• Usually appear 2-4 weeks after continuous grazing
• Horse/swine- related to B1 deficiency
(thiaminase)
• Cattle/sheep – animals hemorrhage profusely
• Loss of condition/weight, incoordination and
crouching position with feed apart and arched
back
Horsetail, Foxtails,
Scouring Rushes
Equisetum arvense
• Horsetail – most common of several
horsetails & most variable
• Two growth forms (sterile & fertile
stems)
– Not found together
– Sterile: light green, highly branched, =
small pine tree
– Fertile: tall, dark green
• Railways, field edges, woods
• Hard to kill
• Most trouble in hay
Field Horsetail, Foxtails,
Scouring Rushes
• Poisoning similar to bracken fern
• Different: maintain appetites even
after clinical signs appear
• Thiamase…B1 deficiency
• Loss of condition, excitability,
staggering
Alkaloid
Ancient Awareness
399 BC Death of Socrates by Hemlock
Charged with religious heresy and corrupting
the morals of local youth.
Active chemical is the alkaloid coniine which
when ingested causes paralysis, convulsions
and potentially death.
Water Hemlock, Cowbane
Cicuta maculata
• One of the most poisonous plants in Ohio
• Shores of lakes, ponds, wet places
• Animals drinking the water from small
pools (crushed plant-toxic alcohol product)
Poison Hemlock,
Conium maculatum
• Tall, erect biennial
– Vegatative rosette the first season
– Upright reproductive stem second
season
• Mouse-like odor
• ½ the counties in Ohio
• Waste areas, partially shadded,
poorly drained sites, stream banks,
edges of cultivated fields
Poison Hemlock
• One of the few green plants in late winter and
among first green plants to green up in early
spring
• Often confused with wild carrot or wild parsnip.
• All parts poisonous
– Roots more toxic than leaves or stems
– Leaves worse in spring
– Roots more toxic over time
Poison Hemlock
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Strong odor usually prevents consumption
Drought, hay, silage though
Symptoms
Dilated pupils, weakness, staggering,
respiratory paralysis 2-3 hours after
ingestion
Common Pokeweed, Pigeon Berry, Scoke,
Garget
Phytolacca americana
• Resembles a small tree (10 ft)
• Base of pokeweed steam typically deep redpurple
• From a distance, the purple fruit resemble a
bunch of grapes
• Throughout Ohio: clearings & open woods
– Becoming more abundant in reduced tillage
fields
Common Pokeweed, Pigeon Berry, Scoke,
Garget
• Livestock will not avoid eating
• Thick, woody roots most poisonous and
account for most livestock poisoning
• Fruit least poisonous but may be
responsible for human death
• Symptoms: Excessive salivation, colic,
weakness, diarrhea (often bloody), severe
case-respiratory failure
Tansy Ragwort
Groundsel
(ragwort)
Groundsel
Groundsels, Ragwort
(Senecio) spp.
• 8 species of Senecio recognized in Ohio
• Most poisonous being the relatively uncommon
cressleaf groundsels (S. glabellus)
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Also called butterweed or yellowtop
Biennial – heights of 1-3 feet
Bright lemon-yellow flower- clusters (April-June)
Wet woods, swamps, stream banks, wet ditches/pasture
Groundsels
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Common groundsel – S. vulgaris
More common
Absence of ray flowers
Solid, shorter stem
Field and waste places
All parts toxic
Toxin greatest in flowers and in leaves just before
reach maturity
Groundsels
• Obvious signs of poisoning often do not
appear until liver damage severe
• Anorexia, depression
• Followed by incoordination, diarrhea,
presence of hemoglobin in urine, cirrhosis
of liver…….death
Jimson Weed
 Used in the Roman Empire and during the
Middle Ages both as cure and a poison
 Women used preparations to dilate their
pupils- a sign of allure and beauty
Jimsonweed, Thorn apple, Jamestownweed
Datura stramonium
• Foul smelling annual
• Stems up to 4 feet tall, smooth, green to
purple
• Leaf similar to a poinsetta
• Flower white to purple
• Fruit is hard, prickly
Jimsonweed, Thorn apple, Jamestownweed
• Common around barnyards, feedlots
(especially hog lots)
• Cultivated fields
• roadsides
Jimsonweed, Thorn apple, Jamestownweed
• All parts of the plant, seeds in particular toxic
• Because of strong odor and taste, animals seldom
consume enough of green plant to be affected
• Problem may be with dry plants in hay or silage,
or from seeds mixed with grain
• Within hours: weak, rapid pulse, dilated pupils,
dry mouth, incoordination, diarrhea, convulsions,
coma and sometimes death
Glucosides
Common Cocklebur
Xanthium strumarium
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Annual weed in agronomic crops
Rich, moist soils
1-2 feet tall
Seeds toxic but seldom consumed
– Burs and spiny
• Tender juicy cotyledons consumable
• As leaves mature, the plant loses toxicity (seeds
still toxic)
• The plant tends to poison pigs more than other
livestock
Common Cocklebur
• Colic, anorexia, depression and weakened
heartbeat
• If survive…develop chronic liver disease
• Fatally poisoned animals may suffer spasms
before dying.
Common Milkweed
Asclepias syriaca
• Stems 3-6 feet in height
• White milky sap
• Flowers in a large fall-like cluster, sweet smelling,
pink-lavender in color, bloom from June to August
• Grows best in warm, dry soils with full sunlight
• Patches on roadsides and in reduced tillage fields
Common Milkweed
• All parts of plant (green or dry) toxic
• Livestock generally avoid unless nothing
else to eat
• Dizziness, loss of muscular control, violent
spasms, rapid and weak pulse, respiratory
paralysis, and rarely death
• Symptoms with in a few hours of ingestion
Nightshade Family
• The Solanaceae or nightshade family contains
several important poisonous plants
• Leaves, shoots, and unripe berries
• GI irritaton and CNS problems
• Eastern black nightshade, bittersweet nightshade,
horsenettle, and two species of groundcherry
• Common potato:
– White sprouts and green parts of plant
– Green skinned tubers
Other
Yellow Sweetclover
• I don’t worry about unless hay is moldy
– Outer portion of a bale
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Thus more likely to see in winter
See when consume for about 2 weeks
Hemorrhaging & abortions
Dicumarol is the problem
Moldy sweetclover Melilotus spp.
• Coumarin present in the clover is converted
by the mold to dicumarol (with high
moisture and mild conditions)
• Cattle are more frequently poisoned
• Can be seen when cattle are being dehorned
and castrated “worked”
Mustards
Brassica spp., Raphanus spp. And related genera
• Many mustards are harmeless when young
• Seeds and vergatative parts may contain the
toxic principle glucosinolate
(isothiocyanate)
• Grain screenings can be a source
• Anorexia, gastroenteritis, salivation,
diarrhea, photosensitization, others
Common St. Johnswort, Klamathweed,
goatweed
Hypericum perforatum
• Eastern Ohio, sporadic in western Ohio
• Branched reddish stems, 3 feet tall
• Bright yellow flowers, black dots on edge
of petals.
• When wet, the seed have a gelatinous
coating that sticks to objects.
• Photosensitization (due to hypericin)
• Problem in all growth stages and in hay
St. Johnswort
St. Johnswort
St. Johnswort
St. Johnswort
CYANIDE: JOHNSONGRASS
SORGHUM HALEPENSE
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Can be up to 10 feet tall perennial grass
Look like a narrow-leaved corn plant
Rich soils
One of the worlds 10 worst weeds
Kill 2 ways:
– Cyanide (hypoxia)
– Nitrates – drought or fertilization
Pigweed
Pigweed, Dock
Amaranthus retroflexus
• Contains soluble oxalates (oxalic acid) and
“perirenal edema factor”
• Also accumulates nitrates
• Signs: incoordination, trembling of muscles,
increased BUN and creatinine accompanied
by protein and glucose in the urine
• Edema at necropsy
2. Trees and Shrubs
Oaks
Quercus spp
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Woodlands of Ohio
Toxin – tannins
Young leaves and sprouts – spring
Acorns - fall
Usually when over ½ the diet
Water where oak leaves have soaked
Abdominal pain, anorxia, colic, constipation,
diarrhea, blood in urine
• Horse less susceptible than ruminants
Oak
Buckeye
Aesculus spp.
• Ohio Buckeye (A. glabra)
– Throughout Ohio
• Sweet or Yellow Buckeye (A. octandra)
– Southern Ohio
• Glycosides, saponin and possibly alkaloids
• Sprouts and leaves in early spring and seeds
are especially poisonous
Red maple
Acer rubrum
• Wilted leaves and have only been reported
in horses
• June through October, but may be most
toxic in autumn
• Dried leaves may remain toxic for 30 days
• Why toxic…..I’m not sure
Black Walnut
Juglans nigra
• Black walnut fruits consist of a nut
surrounded by a thick husk and do not split
open when ripe
• Horses-shavings (<20% in shavings can
cause poisoning in less than 24 hr)
Wild Black Cherry, Choke Cherry, and
Peach
Prunus spp.
• Crushed twigs and leaves yield a strong cyanide
odor
• Seeds, twigs, bark and leaves contain a glycoside.
• Poisoning occur most frequently when wilted
leaves leaves, branches in field after a storm
• Ruminants appear to be more susceptible than
horses
Prunus (cherry)
Prunus (cherry)
Prunus (cherry)
Yews
Taxus spp.
• Evergreen shrubs
• Canada yew (ground-hemlock) native to
Ohio
• Japanese yew and English yew – yard
ornamental
• Will readily consume even when forage
available
Blue green algae
(Pond Management)
• Anabaena spp.,
Aphanizomenon spp.,
Microcystis spp.
• Ponds with fertilizer
runoff in warm
weather
• Neurotoxic alkaloid
and anticholinesterase
toxins [anatoxin-a and
anatoxin-a (s)]
• Kill blooms with
copper sulfate
• Drag burlap sack with
copper sulfate
(bluestone) around
pond
• Caution with catfish
(do ½ of pond) and
come back a few day
later and do other half
Ornamentals
• Don’t throw over the fence
• Too many to name that are toxic