|
Symptoms from these plants vary from instant death to severe health problems to mild health conditions. For toxic plants common in your area consult your local agriculture extension office.
Information on this page comes from various extension offices across the US, but may not be complete. Do not assume a plant is not toxic just because it is not listed here.
This material is provided as information only. Please contact your veterinarian or poison control if poisoning is suspected.
Some plants and weeds listed here are taken from a North
Carolina State University and Oregon State University.
Photos of Poisonous Weeds
Toxicity Level
Alfalfa
(when blister beetles are baled in it)
Dangerous |
Annual Buttercup
Creeping Buttercups
Widespread,
but of minor importance
Creeping Buttercup-Causes diarrhea, reddening of mucus membranes,
excessive salivation. Enzymes are released when chewed and can be passed in
mother's milk. Plant does not seem to be toxic when dried. Most animals recover
when removed from the plant. |
Arborvitae
Dangerous
but uncommon |
Baneberry
Dangerous
Snakeroot
(Baneberry, White Cohosh, Snakeberry, Doll’s Eyes, Coralberry)- Causes excessive salivation,
burning of the mouth and throat, gastro-intestinal distress, diarrhea, hallucinations and excitability.
This plant is only toxic if eaten in large quantities. The associated burning of the mouth and throat
seem to prevent an overdose of this plant. If an animal does ingest this plant use extreme care when
handling the animal as it will be unpredictable. Avoid stressing or exciting the animal as this can
accelerate the toxins. |
Bitter weed or
bitter
Sneezeweed
Dangerous
Bitter weed- Causes excessive salivation, elevated temperature,
difficulty breathing, vomiting and convulsions. This plant is common
in pastures and grazing areas, but is seldom eaten unless no other plants
are available. It is seldom fatal unless a large quantity is eaten, however
it can cause long-term effects. Call the vet immediately if the animal is seen eating it. |
Black Cherry
Dangerous
Cherry- Causes anxiety, breathing problems, staggering, convulsions,
death. Animals with single gastric systems are less susceptible than those
with multiple stomachs. When the leaves are intact they are harmless, but if
they are damaged (frost, trampled, wilted, blown down) they produce cyanide.
Most animals can safely eat small amounts of the plant safely, but if they
eat large amounts or damaged leaves poisoning will occur. Chokecherry,
apricot pits, peach sprouts and apple seeds can also poison. Cyanide poisoning
comes on quickly and often the animal is found dead. If caught quickly,
within a few minutes, an antidote can be given. Do not stress the animal as it
may worsen or accelerate the symptoms.
|
Black Locust
Dangerous
Black Locust- Causes depression, lack of appetite, weakness, paralysis,
diarrhea (may be bloody) and death. Symptoms can appear as soon as an
hour after ingesting. Related Honey Locust and Prickly Ash may also provide
similar symptoms. If enough of the plant (leaves and/or bark) is
ingested death may occur within a few days. However, it is not always fatal.
Treatment must be started immediately and include emergency measures to
remove the plant material from the gastrointestinal tract.
|
Black Walnut
Dangerous
but rarely eaten
Black Walnut- Causes laminitis, breathing problems, respiratory
difficulties, gastroenteritis. If horse's bedding includes more than
20% of Black Walnut it can result in laminitis and/or colic. Pollen and fallen
leaves can produce respiratory problems/allergies. Remove the shavings;
cool the feet and/or legs with water. Respiratory problems do not usually
require special treatment unless severe.
|
Bladder pod
Dangerous
Tall woody annual herbs; these cause gastroenteritis,
bloody diarrhea, shock, and death
but rarely eaten |
Bleeding Heart
Dangerous
but rarely eaten
Bleeding heart- Causes trembling, staggering, vomiting, diarrhea, convulsions, labored breathing and skin irritation if in
contact with sap. Toxic if eaten in large quantities. Skin irritations can last long or short term depending on the
length of time contact was made with the sap. |
Bloodroot
Dangerous
but rarely eaten
Bloodroot- Causes nausea, vomiting, dizziness, dilated pupils, diarrhea, fainting and heart failure.
This plant is HIGHLY toxic. Best line of defense is to remove it from any areas where animals may come
in contact with it; care should be used when removing the plant so that limited contact is made with it. |
Boxwood or
Buxus
Dangerous
but generally unavailable
Boxwood- Causes nausea, vomiting, diarrhea, dizziness, convulsions and respiratory distress.
Contact with the sap from this plant can cause skin irritation. |
Western Brackenfern
Dangerous
Brakenfern- Causes weight loss, weakness, gait abnormalities, tremors,
weakness, abnormal heart rate, spasms, fever, death. Horses may not
show signs of toxicity for two to three weeks after consuming the plant, but
need to eat the plants for one to two months before showing signs. Remove
the animal from the plant and do not feed hay that includes the plant.
Treatment includes daily injections of thiamine for up to two weeks if caught
before the animal cannot rise (at that point it is too late). |
Buckeye or
Horse Chestnut
Dangerous
Buckeye (Horse Chestnut)- Causes abdominal pain, diarrhea, slobbers,
trembling, staggering, difficulty breathing, paralysis, coma, death.
These trees leaf early and animals may be tempted to eat the leaves.
Emergency measures include removing the plant material from the gastrointestinal
tract. Once signs are present only supportive care can be given, there
is no antidote. |
Buttonbush
Dangerous
produce gastrointestinal irritation upon ingestion.
Animals will typically avoid eating this plant BUT will eat it if they are extremely hungry and no other feed is available
Signs: mild depression, vomiting, abdominal pain, diarrhea (may turn bloody). Call a veterinarian if animals are severely affected and do not recover within 12 to 24 hours
but rarely eaten |
Camas, death Camas, black snakeroot
Dangerous
but rarely eaten
Death Camas- Causes muscular weakness, convulsions, death, vomiting, and
coma. No specific treatment available. Similar signs have been reported
with stagger grass in sheep.
|
Castor bean
Dangerous
but generally unavailable
Castor Bean (Castor Oil Plant)- Causes stomach irritation, diarrhea,
abdominal pain, increased heart rate, sweating, collapse, convulsions,
death. Commercially prepared castor oil does not contain any toxins.
The seeds must be chewed or broken open to activate the toxicity, unopened
seeds can pass with no harm to the animal. If the animal is observed eating
the seeds call the Vet IMMEDIATELY, once signs are apparent only supportive
care can be given. If several hours lapse between eating, treat for shock
and symptoms, but death will likely occur since this plant's toxins are
powerful. |
Cedars
Slight |
China Berry
Minor importance
Chinaberry- Causes stomach irritation, bloody diarrhea, paralysis, irregular breathing,
respiratory distress and death. The “fruit” or berries of the plant are highly toxic as
are any teas made from the plant. The plant contains neurotoxins that can be deadly in large amounts. |
Climbing bittersweet
Minor importance
Bittersweet- Causes diarrhea and loss of consciousness. There is low toxicity when eaten, but due to the side
effects it is not recommended to all the plant to invade pasture and grazing areas. |
Cocklebur
Dangerous
Cocklebur- Causes gastrointestinal irritation, weakness, behavioral
changes, breathing difficulties, cardiac abnormalities, hypoglycemia (low blood
sugar). Horses are less at risk than cattle, poultry, swine or sheep.
Once toxic signs develop death may follow in 48 hours. Some may recover, but
it may take weeks. Prevent further consumption, keep animal quiet and call
a vet immediately.
|
Corn Cockle
Dangerous
but rarely eaten
Corn Cockle- Causes severe stomach pain, diarrhea, dizziness, weakness, and slowed breathing.
This plant is a non-native plant. It can often contaminate wheat, oats and ground corn. While
toxicity levels are low when ingested, care should be used to avoid contamination.
|
Coast Fiddleneck
Dangerous
Fiddleneck (tarweed)- Causes photophobia, photosensitivity, jaundice,
liver failure, diarrhea, depression, aberrant behavior (head pressing,
incessant licking, aimless walking), weight loss, edema of the extremities. As
little as 15 mg of dried plant per kilogram of weight over 2 weeks will induce
severe liver failure. Keeping in a dark stall can treat the
photosensitivity, but the underlying liver problem is rarely if ever
treatable. Prognosis is very poor.
|
Curly Dock
Dangerous
but rarely eaten
Curly Dock- Causes coma and death, kidney damage, tremors, depression,
weakness. Animals that survive the acute effects often contract kidney
disease. Immediate treatment with limewater orally may limit the
absorption of the toxin. Intravenous treatment with calcium gluconate, magnesium
and electrolytes may help acute symptoms. |
Crotalaria or
Showy Rattlebox
Dangerous
The seeds contain a saponin which is quite toxic to poultry, cattle, sheep, goats and humans.
Animals appear severely depressed, have a rapid pulse and diarrhea. Poisoning usually occurs in the fall when other forage is scarce |
Dogbane
Dangerous
Dogbane (Indian Hemp)- Causes cardiac arrest and death. This plant is HIGHLY toxic,
even when dried. Care should be used when removing the plant to assure that all parts
are removed from pasture and grazing areas. Do not allow any part of the plant to get
into the human system, as it is toxic to humans as well. |
Dutchman's Breeches
Dangerous
Dutchman’s Breeches- Causes trembling, staggering, diarrhea, convulsions, respiratory distress and
skin irritation. Skin can become irritated if it comes in contact with sap. Irritation can last for
a few minutes, up to hours. The plant is toxic if eaten in large quantities, however care should be
taken to remove it from pasture and grazing areas. Extra care should be taken when removing the plant
to avoid skin irritation. |
Elderberry
Dangerous
but rarely eaten
Elderberry- Causes nausea, diarrhea and coma. The leaves, stems and unripe fruit are toxic. However, in certain areas of
the country humans routinely eat other parts of the plant. The plant is toxic when eaten in large quantities, but is seldom
palatable to grazing animals. Ripened berries can cause staining on coats, but skin irritation is seldom noted. |
False Hellebore
Dangerous
but rarely eaten
False Hellebore (skunk cabbage, corn lily)- Causes congenital birth defects, low blood pressure. Prevent pregnant animals from
grazing on the plant. Plant seldom causes death. |
Fox Glove
Dangerous
Foxglove- Causes nausea, diarrhea, stomach pain, severe headache, irregular and slow pulse,
tremors, convulsions and death. Contains cardiac toxins. This plant is HIGHLY toxic and may be fatal if ingested. |
Foxtail Barley
Dangerous
Foxtail Barley (squirrel tail barley, wild barley)- Causes stomach
irritation, abscesses, mouth/ear/nose/eye/skin irritation. Yellow or
green foxtail, rye and millet can cause similar problems. For minor
irritation give supportive care; most will resolve within a day. If more severe,
signs of irritation, if the eyes or ears are involved or if the animal cannot
eat call the vet. In some cases surgery may be required to remove the awns.
|
Slender Fumewort
Dangerous
but uncommon |
Ground Cherry
Dangerous
but rarely eaten
Ground Cherry- Causes headache, stomach pain, lowered temperature, diarrhea, circulatory and respiratory depression, loss of
sensation and death. While some parts of the plant are known to have been eaten safely, it is not recommended for it to
remain in pasture and grazing areas. This plant is highly toxic and can be fatal if ingested. |
Horsenettle
Dangerous
but rarely eaten
Horse nettle- Causes nausea, excessive salivation, drowsiness, abdominal pain, diarrhea, weakness, respiratory depression and death.
The berries are the toxic part of this plant. The plant may be fatal if large quantities are eaten. |
Horsetail or scouring rush
Dangerous
but rarely eaten
Horsetail (scouringrush)- Causes weight loss, weakness gait
abnormalities, abnormal heart rate and/or rhythm, death. This plant causes a thiamine
deficiency and can be treated by a vet. Also see Brakenfern.
|
Hydrangea
Dangerous
but uncommon |
Jimsonweed or
Thorn Apple
Dangerous
Jimsonweed (thorn apple)- Causes agitation, trembling, delirium,
convulsions, coma, death. Animals are reluctant to eat this plant, even when forage
is sparse. The plant may become more palatable if treated with weed
killer, so remove animals until plants are completely dead and removed. Once eaten
the signs become apparent within a few minutes to several hours. Use
caution when working with an animal to avoid injury as they can be highly
agitated or delirious. Contact a vet to perform emergency measures to remove the
plant from the gastrointestinal tract. There are medications to
counteract the toxins. For animals less severely affected, the animal could
recover within a few days. Keep the animal quiet and undisturbed (except for the vet). |
Johnson grass
(when stressed)
Dangerous
but rarely eaten by horses
Johnson Grass- Causes breathing problems, anxiety, staggering,
convulsions, coma, death. This plant contains cyanide. Other members of this grass
genus includes Sudan grass and Milo, although their toxicity is lower than
Johnson Grass. The most common type of poisoning from this plant occurs when
the plant has been damaged (i.e. trampled, frost, etc). When the plant is
dried the levels of cyanide are very low and it is safe to feed. Clinical
signs can come on quickly and often the animal is simply found dead. If the
animal is exhibiting signs call the vet IMMEDIATELY, time is of the essence.
Since the animal will be highly stress, take caution in working around the
animal. Avoid stressing the animal as it can accelerate the condition or make
it worse. Treatment must be given quickly, although there is an antidote.
|
Lily
Easter Lily
Dangerous
but uncommon
(Easter Lily)- Mostly lethal to cats, although the plant should
be considered a possible threat to any animal prone to eating plants.
Horses do not seem to eat the plant, but limiting access seems prudent.
|
Lily-of-the-Valley
Dangerous
but uncommon
Lilly-of-the-Valley- Causes excessive salivation, watery eyes, sweating, abdominal pain, weakness, convulsions and death.
This plant is largely an ornamental plant, but may grow wild near old homesites. The plant is highly toxic to all animals,
so recommend that it be removed from areas where any animal may come in contact with it. |
Tall Larkspur
Dangerous
Larkspur- Causes bloat, muscles tremors, respiratory paralysis.
Foothills Larkspur seems to be the most toxic. |
Lupine
Dangerous
Causes breathing problems, behavioral changes, trembling, birth
defects, coma, depression, death. Danger from this plant is higher in
western rangelands where the plants grow and flourish. Signs of
poisoning can develop within an hour to 24 hours from consumption. There is no
antidote for Lupine, treatment includes removing the plant material
from the animal's reach, rest, and lowering stress. Trailering the animal or
handling can increase symptoms and increase the chance of death.
|
Marijuana
Hemp, hashish, hash
Dangerous
but uncommon
Marijuana (Hemp, hashish, hash)- Causes behavioral changes, difficulty
breathing, depression, trembling, diarrhea. Fatalities with this plant
are rare, but do occur. This plant remains toxic even when dried to all
contact should be limited. In most cases the effects of the toxicity will wear
off within a few hours with limited lasting effects. However, in cases of
extreme poisoning supportive care may be needed. |
May apple or
Mandrake
Dangerous
but rarely eaten
Mayapple (Mandrake)- Causes excessive salivation, diarrhea, excitement, fever, coma and death. Some parts of the plant, ripened
fruit, may be safe for humans to eat. However, this plant is HIGHLY toxic and may cause death if eaten. |
Mayweed
Dog Fennel
Dangerous |
Milkweed
Dangerous
but rarely eaten
Milkweed- Causes gastrointestinal distress (bloating, colic, diarrhea),
in coordination, tremors, accelerated heartbeat, difficulty breathing,
death. Milkweed is seldom eaten as the plant is not palatable, but animals may
eat if other forage isn't available. There is no treatment available for
this plant. If the animal is seen eating the plant calling the vet and
emptying the plant from the gastrointestinal tract may help. If the animal
simply nibbles the plant it may cause oral irritation that keeps the animal
from eating the plant again.
|
Mistletoe
Minor importance
Mistletoe- Causes stomach and intestinal irritation, diarrhea, lowered blood pressure, and irregular pulse.
This parasitic plant is a perennial favorite during the holidays, but can be toxic to animals. |
Monkshod
Dangerous
but uncommon
Monkshood- Causes diarrhea, weakness and muscle spasms, respiratory paralysis, convulsions and death. This plant may be found
in ornamental gardens. It is highly toxic and it may be fatal if eaten by any animal. |
Mustard plants
Causes photosensitivity, breathing difficulty, oral
distress, gastrointestinal distress (diarrhea, colic). There is no
antidote to mustard poisoning. Supportive care is the only treatment (i.e. move
to a dark stall for photosensitivity, remove the plant from grazing areas). |
Hairy Nightshade
Dangerous
Nightshade (deadly nightshade, black nightshade, hairy nightshade)-
Causes diarrhea, muscle tremors, weakness, shock, coma, death, depression,
decreased cardiac output, lack of coordination, dilated pupils, kidney
failure. Cooking destroys the toxic alkaloids of the plant. Other
members of the nightshade include tomatoes and potatoes. Supportive therapy
includes intravenous fluids and electrolytes. |
Mountain Laurel
Dangerous
Mountain Laurel- Causes excessive salivation, watery eyes, runny nose, slow pulse,
nausea, abdominal pain, sweating, lack of coordination, convulsions and death.
This plant is highly toxic and may be fatal if eaten. |
Oak Leaves and Acorns
Minor importance
White Oak (Gambel’s Oak)- Causes dark "tarry"
diarrhea, loss of appetite, depression, liver damage, hemorrhagic gastroenteritis, kidney and/or liver failure.
These plants are toxic at any stage, but seem even more toxic when in bloom. Once signs are evident the renal
damage is done and prognosis is poor. Aggressive fluid therapy may help support renal function and to re-hydrate
the animal |
Oleander
Dangerous
but uncommon
Oleander- Causes gastrointestinal distress (colic, bloody diarrhea),
cardiac difficulties, sudden death. This plant is highly toxic and should never
be planted where the animal grazes or can reach. ¼ of a pound of leaves
can cause the death of a horse. Even the dried leaves are toxic, and may be
more palatable to animals. So, use care when disposing of cut limbs or
leaves. If an animal is seen eating this plant IMMEDIATELY call a vet. This plant
is lethal even in small doses. The vet can evacuate the gastrointestinal
tract and administer medications to alleviate some of the toxins.
|
Perilla Mint
Dangerous
Animals shows signs of respiratory distress. There is difficult
breathing especially when exhaling. Grunting is often seen when
exhaling. There may be a nasal discharge, elevated temperature.
Once symptoms of severe pulmonary edema and emphysema are observed, treatment is usually ineffective. Injections of antihistamines, steroids and antibiotics are indicated. Cattle should be handled quietly to prevent further respiratory complication and subsequent death.
|
Pigweed
Dangerous
but rarely eaten
Pigweed (Redroot Pigweed)- Causes breathing problems, weakness,
abortions, coma, kidney failure, death. This plant is seldom eaten, it isn't
palatable, and effects sheep and cows more than horses. A vet can provide
supportive care and recovery is likely unless the animal develops the kidney failure. |
Pines
Slight |
Poison Hemlock
Dangerous
but rarely eaten
Hemlock- Lethal dose for horses is 4-5 pounds and signs present within
2 hours of ingesting. Causes excitement in the beginning, decrease
cardiac and respiratory output, colic, bloating, coma, death. Plant may be more
palatable in the spring or after treatment to kill the plant, so make
sure the plant is killed and removed BEFORE reintroducing animals to the
area. If animals are seen ingesting the plant call the Vet IMMEDIATELY.
Treatment is intense and requires intense nursing, including supportive care and
removing the toxins from the gastrointestinal tract. |
Pokeweed
Dangerous
Pokeweed (Pokeberry, Inkberry, Pigeonberry)- Causes burning of the mouth and throat,
excessive salivation, severe stomach irritation, bloody diarrhea, convulsions and death.
Although recipes abound, this plant is considered highly toxic and can be fatal if eaten. |
Rattlebox or
Chinese Wisteria
Dangerous
Rattlebox (False Poinsettia)- Causes nausea, diarrhea, intense stomach pain, weakness,
depression, respiratory failure and death. As with true Poinsettia this plant is highly
toxic to animals and should be avoided for holiday celebrations in homes where there are pets.
It should also not be grown in or near pastures or grazing areas. |
Red Maple
(stressed leaves)
Dangerous
but rarely eaten
Red Maple- Causes breathing difficulties, jaundice, death, depression and increased heart rate. Ingesting 1.5 pounds is toxic
and 3 pounds is lethal and wilted or dry leaves maintain their toxicity for well over a month. Healthy leaves have not been
implicated in any deaths, but it isn’t advised to allow the leaves near any horse. Dry and wilted leaves have caused death.
The toxins effect the red blood cells. Treatment includes using dry activated charcoal and/or mineral oil to prevent absorption.
Treatment also includes support and treating symptoms and may include blood transfusions. |
Rhododendron
Dangerous
Rhododendron- Causes excessive salivation, watery eyes and nose, abdominal pain,
lethargy, depression, diarrhea, weakness, respiratory distress, progressive paralysis,
coma and death. Most often known as an ornamental or houseplant, this plant can also
grow wild. It is highly toxic and should be removed from areas accessible to animals. |
Scarlet pimpernel
Dangerous
but rare |
Scott's broom
or
Scotch broom
Minor importance
Scotch Broom- Causes excitement, muscle weakness, convulsions and death. Caution should be taken not
to excite or stress the animals since this can intensify the effects. Contain the animal taking care
to avoid injury as the animal can behave unpredictably. Call the vet IMMEDIATELY if poisoning is suspected. |
Sesbania
Dangerous
Tall woody annual herbs; these cause gastroenteritis, bloody diarrhea, shock, and death
but uncommon |
Smartweed
Minor importance |
Sorghum and Sudan grass hybrids
Milo (Grain Sorghum)
(when stressed)
Dangerous
Sorghum (Sudan grass)- Causes urinary incontinence, difficulty breathing, weight loss, abortion, lower spinal cord degeneration.
Sudan grass contains cyanide and is high in nitrates, although some hybrids have been developed that contain no cyanide and are
safe. Intravenous fluids are the course of treatment, along with sodium thiosulfate mixed with water via mouth. |
Spruce
Minor importance |
Spurge
Minor importance
Spurge (Eyebane)- Causes diarrhea, abdominal distress, skin irritation and photosensitivity.
Skin irritation may last a short time. Remove the animal from the sun and keep away from sunlight
in a darkened stall. Use care not to overly excite or stress the animal as it may intensify effects and call a vet. |
St John's Wort
Minor importance
St John's wort (Klamath weed)- Causes acute inflammation and necrosis of
tissues, cell death, sloughing of the skin, photosynsensitization,
severe damage to blood vessels. Remove the animal from the sun and keep in a
dark stall. Antihistamines and anti-inflammitories may help if given early
enough. |
Stagger grass or
Copper Lily
Dangerous
Staggerweed- Causes intense diarrhea, muscle weakness and spasms, weak pulse, respiratory paralysis, convulsions and death.
This plant is highly toxic and can be fatal if ingested. |
Yellow Star thistle
Dangerous |
Star-of-Bethlehem
Dangerous
but uncommon
Star-of-Bethlehem- Causes excessive salivation, diarrhea, swelling of tongue and throat and difficulty breathing.
Skin irritation can occur after prolonged contact with the plant. Care should be used when removing the plant,
because in addition to the above symptoms humans can also get swollen lips and vomiting. Contrary to what may have
been published elsewhere, the bulbs of this plant are NOT edible. |
Sweet Shrub
(Sweet Bubby, Carolina Allspice, Sweet Bubby
Bush
)
Dangerous
but rarely eaten
Sweet shrub (Carolina Allspice, Sweet Bubby Bush)- Causes convulsions, elevated blood pressure and sometimes death.
The seeds are the toxic part of this plant, so care should be used that no seeds contaminate feed.
The plant is toxic if eaten in large quantities. |
Sweet Clover
(when frosted or baled wet)
Minor importance
Symptoms are related to massive blood loss. Swellings appear under the
skin due to accumulations of blood. These swellings vary in size and may
occur at any site on the body, but particularly in areas that are
susceptible to bruising. Pale mucous membranes, rapid and weak pulse,
and weakness are observed. Sometimes animals hemorrhage internally and exhibit signs of shock.
Affects mainly cattle, but have been known to affect horses and sheep. |
Tall Fescue
(Endophyte)
Moderately toxic problems common |
Tansy Ragwort
Dangerous
Tansy Ragwort- Causes colic, convulsions, abortions. Not a commonly
reported toxic plant since animals rarely ingest it although it does occupy a
significant amount of acreage. Risk of death or serious illness is low
with this plant. Most deaths and illness associated with this plant is from
humans attempting to use the plant extract for medicinal purposes. |
Hairy Vetch
Dangerous
Vetch- Causes diarrhea, sudden death, abnormal behavior, difficulty
standing, convulsions, swollen lymph nodes, welts on skin. Plant causes
immune mediated disease and seeds may contain cyanide. Mortality rate
is
very high. |
Western Hemlock
Dangerous
Western Water Hemlock- Causes teeth grinding, convulsions, muscle degeneration (including heart muscle),
respiratory paralysis, dilated pupils and sudden death. Death generally occurs within 2 hours of onset of symptoms.
There are 4 major species of this plant in North America and all are toxic. To treat induce vomiting and give laxatives,
intravenous administration of sodium pentobarbital at the onset of seizures may help prevent lethal cardiac and muscle
degeneration. |
White Snakeroot
Dangerous |
Wild parsnip or
spotted cowbane
Dangerous
Wild Parsnip- Causes skin irritation after
contact with the sap, can also cause irritation or blisters in the mouth. Some parts of the plant are
known to be edible for humans if properly prepared. |
Wild Iris
Dangerous |
Yew
Dangerous
but uncommon
Yew- Causes trembling, breathing problems, diarrhea, heart problems,
but usually sign is just found dead. A single mouthful can cause death in
horses in less than 5 minutes. 0.01 to 0.05% of body weight is lethal for any
animal. Treatment is impractical since death is so quick. The best
treatment is assuring that no yew is planted near pastures and no leaves or
cuttings are thrown into areas where horses can reach.
|
Wooly Croton
Minor importance
Woolly Croton- Causes diarrhea, nervousness, blisters and possibly death.
Use care when handling an animal that has ingested this plant as it may be excitable and unpredictable.
Also, use care when removing the plant from pasture and grazing areas since contact with the plant sap can
cause skin irritation and blisters. |
|
Associated Toxicities of Some Pasture Plants
- Red Clover
-
Black patch fungus on leaves causes slobbers. In horses it can cause
dehydration to a life threatening degree. This fungus is also
found quite often on white clover types and should be suspected
anytime excessive slobbering is observed in the horse.
- Sudan grass or Sorghum
- Can cause cystitis syndrome when grazed after a prolonged drought
or heavy frost. While these compounds break down in hay in a
matter of a few weeks these forages are still not recommended for
horse hay due to the difficulty in drying down the thick stems
and the attendant risk of the hay molding in the bales.
- Nitrates
- Can cause poisoning and death in heavily fertilized grass
pastures and hay fields especially in drought conditions.
- German Millet
- When fed as a major forage can cause kidney, joint and bone
problems, especially when plants are mature.
- Lush pastures
- Horses unaccustomed to lush pasture can colic or founder if
suddenly changed to them.
- Tall fescue
- Tall fescue is our most common pasture grass and hay species
primarily because of its resiliency and low maintenance. A large
measure of these benefits can be attributed to the presence of an
entophytes fungus living in a symbiotic relationship within the
plant. The fungus also produces an alkaloid which causes a
number of problems for cattle and bred mares.
| |
