CPB Tox Plants Flashcards

Terms Definitions
Yew species
Tobacco: toxin
Black Walnut: Toxin
•Lupine sp. (Bluebonnets)
•Perennial herbs,
•12 to 30 inches high. Elongate spikes of blue, purple, white pea-like flowers in early summer followed by 1 to 2 inch fuzzy, pea-like pods
•Species affected: Livestock in NW to SW U.S. (Do grow in parts of Indiana)
-Causes more losses of sheep that any other plant in NW U.S. through overgrazing or driving flock through heavily infested area.
•Dangerous parts:
-All, esp seeds
•Toxin: Lupinine
•Signs: Dyspnea, "snoring", trembling, convulsions, death within 24h (nicotine-like signs)
•Diagnosis: History, evidence of ingestion
Jimsonweed: toxin
Atropine, scopolamine
Pokeweed: species affected
Mustards: toxic parts
Red Maple: species affected
Oak: Toxins
Gallotannins and Tannins
•Sneezeweed (Helenium sp)
•Mainly western U.S. A few species may grow in Indiana. Poisoning more common in late summer or fall
•Dangerous parts: All
•Species affected: Livestock
•Signs: GI irritation; salivation, vomiting, diarrhea, weakness, death
•Diagnosis: History, evidence of ingestion, GI irritation, hepatic damage, kidney damage.
•Toxic agentA sesquiterpene lactone is responsible for the toxicity of bitter sneezeweed, which is greatest at time of flowering. This bitter plant is seldom consumed at a level high enough to produce clinical signs. However, it has been responsible for bitter, undrinkable milk and is suspected to be the cause of unpalatable meat from calves slaughtered off the range. The toxin is stable in plants contaminating hay.
Redroot Pigweed: species affected
Jimsonweed: species
Datura stramonium- disturbing/divided?, straw/litter?
Nightshade family
Cocklebur: species affected
esp. swine
Buckeye & Horsechestnut: Toxin
St. Johnswort: species affected
Fescue: Toxin
Ergovaline (ergopeptide alkaloids)
The endophyte contains the toxins which cause peripheral vasoconstriction
The endophyte also interferes with the release of prolactin from the pituitary gland
White snakeroot: toxin
Tremetone or Tremetol
•Yew (Taxus sp)
•Common ornamental shrub
•Uncommon cause of toxicosis in small animals, BUT, a 50 pound dog would only have to ingest about 0.1% BWt (less than 2 ounces) to receive toxic dose. Deaths reported in guinea pigs fed branches.
Buckeye & Horsechestnut: species affected
Pokeweed: toxic parts
All esp seeds
Jimsonweed: toxic part
all especially seeds
Yew: Treatment
No specific treatment
Can try activated Charcoal
can try rumenotomy
Yew toxin
Taxines (group of related alkaloids)
Avocado: signs
Cardiomyopathy- cardiac necrosis and heart failure within days, can recover
in milking goats, cattle, rabbits, and mares after eating leaves.
Poisonous plants outside of indiana
Death Camas
Yellow Star Thistle
Sweetclover: MOA
dicoumarol interacts with epoxide reductase and inactivates it. THis prevents the conversion of vit K to an active form. THis prevents the production of clotting factors 2, 7, 9, 10 which shuts down the clotting cascade leading to a bleeding tendancy
Sweetclover: diagnosis
History, ingestion, gross hemorrhage, and coagulopathies. Forage/liver dicoumarol concentration
Poison Hemlock: diagnosis
History, evidence of ingestion
Ragwort: MOA
Hepatic degeneration leading to cirrhosis. Liver cells can't divide and regenerate so just die off slowly and are trying to divide but can't so get very large.
Cocklebur: diagnosis
Diagnosis: History, evidence of ingestion, increased liver enzymes. At necropsy, GI irritation, HEPATIC DAMAGE, kidney damage
White snakeroot: diagnosis
History of consumption
Plants in stomach/rumen
Elevated CK
Myocardial necrosis
Nightshade & Nettles: toxin
Solanine (and other alkaloids)
Fescue: Diagnosis
History of eating fescue
Stain grass with methylene blue and look for endophyte
Red Maple: treatment
Give lots of fluids
Maybe transfusion
Easter/Tiger Lily
•Easter & Tiger Lilies (Lilium sp)
•Common ornamental plants in Midwest
•Species affected: CATS
•Toxin: Unknown
•Signs: Related to severe kidney necrosis and related sequelae.
•Diagnosis: History, evidence of ingestion
Oleander/Rhododendron/Azalea: diagnosis
History, evidence of ingestion. Test stomach contents for glycosides
Oleander/Rhododendron/Azalea: signs
Often found dead. Occasionally see seizures. Can have vomiting/diarrhea
Poison Hemlock: toxic part
all, especially young leaves
Pokeweed: signs
Signs: Severe GI irritation with vomition (if possible), bloody diarrhea, convulsions if severe (rare)
Buckeye & Horsechestnut: diagnosis
History, evidence of consumption
Yew: Diagnosis
History of eating yew
Leaves in the stomach
Test stomach content for taxines
Nitrate accumulation conditions
Nitrate accumulation in plants depends on weather and fertilizer
More often a problem in hot dry years when a lot of fertilizer is added.
Fescue: species affected
Cattle- summer syndrome, fescue foot, fat necrosis, decreased reproduction, agalactia
Pigs- decreased reproduction, agalactia
Sheep- decreased reproduction, agalactia
Horses- prolonged gestation, abortion, v. sensitive
Cyanogenic: Treatment
Warefar agent so a treatment was developed
Nitrite + thiosulphate
Nitrite binds to cyanide to form cyanomethemoglobin since CN has a higher affinity for methemoglobin than for cytochrome oxidase heme groups. Then, thiosulphate binds to the cyanide to form thiocyanate which can be excreted.
Cyanogenic: Prevention
Test the forage
Wait for it to evaporate from hay before feeding
Water Hemlock: diagnosis
History and evidence of ingestion. Plants in stomach contents.
Sweetclover: treatment
Vitamin K1. Vit K3 is ineffective after coagulopathy has begun
Yew: Mechanism of action
Slows down depolarization of cardiac myosites
Yew: species affected
All, but mostly cattle, sheep, horses, goats
Red Maple: prevention
Keep horses away from tree knocked down in a storm
Cyanogenic: Diagnosis
Look for CN in places with a lot of mitochondria:
Cocklebur: toxic dose
0.75 to 1.5% BWt of young, cotyledonary seedlings can be fatal.
Oak: Species affected
most at risk: are cattle and sheep on pasture, horses too.
Goats may be more resistant
Nightshade & Nettles: toxin part
Whole plant
Green berries > ripe berries > leaves > stem & roots
mature > immature
Toxicity not lost on drying hay
Fescue: fat necrosis
Happens to cattle. The blood supply to the fat becomes constricted leading to ischemic necrosis of the cow's fat
Will feel hard nodules on palpation and see the lumps on necropsy
Cyanogenic: clinical signs
Usually die too fast to see any
If you were watching them might see sudden onset of:
Clonic convulsions
Yew: Clinical signs
They may be found dead
may look ok then gasp and suddenly die- BOOM!
Respiratory trouble
Horse tail & Bracken fern: clinical signs
Weight loss, weakness, ataxia, posterior paresis/paralysis. Terminal opisthotonos and convulsions.
St. Johnswort: toxic dose
1 to 5d after eating 1% or more
Horse tail & Bracken fern: mechanism of action
Thiamin is necessary for cellular metabolism and deficiency results in CNS signs
Ragwort: toxic dose
-1 to 5% BWt in 1 to 2d = acute death.
-12 to 150% BWt over 1 to 5 months = chronic syndrome
Cocklebur: toxin
Oak: Toxic part
•Foxtail (Hordeum jubatum)
•Perennial weedy grass
•Species affected: Grazing livestock, dogs
•Dangerous part: Seed heads (awns)
•Signs: Salivation (oral lesions can be mistaken for foot and mouth disease or other vesicular stomatitides)
•Diagnosis: History, oral ulcers from mechanical trauma, awns in nares, ears, lungs
Tobacco: species
Nicotiana- victory/conquest
Water Hemlock: toxin
Mustards: species affected
Tobacco: toxic dose
Oak: Treatment
No specific treatment
•Larkspur (Delphinium sp)
•Annual or perennial herb, 1/2 to 4 ft high.
•Elongate clusters of spurred white or blue flowers.
-More common in southern Indiana
•Species affected: Cattle, sheep, horses
-Causes more cattle losses in west than other plant
•Dangerous parts: All esp seeds and young leaves
•Toxin: Neuromuscular blocking agent (curarae-like)
•Signs: Often, sudden death. Muscle tremors, weakness, bloat, collapse, death due to resp paralysis 3 to 4h after lethal dose
•Diagnosis: History, evidence of ingestion
Redroot Pigweed: toxic part
Mustards: species
Brassica sp- cabbage
Tobacco: toxic part
Leaves primarily
Nitrate: clinical signs
Hypoxia causes:
Sudden death
Abortion storms
Fescue: treatment
Domperidone- dopamine receptor antagonist so stops the inhibition of the pituitary which normaly receives dopamine and doesn't release prolactin. So, with lack of dopamine, it will release MORE prolactin to counteract the effects of ergovaline decreasing prolactin. This can be given to mares for the last 30 days of pregnancy
Don't feed fescue
•Locoweed (Astragalus sp. & Oxytropis sp)
•NW and SW U.S.
•Species affected: Equine, bovine, ovine can become habituated to eating these plants.
•Toxin: Swainsonine (mannosidase inhibitor)
•Signs: Following several months of ingestion; depression, ataxia, tremors, dysphagia, hyperexcitability (equine), paraplegia, death
•Diagnosis: History, evidence of ingestion, histological evidence of mannose in brain
Black Locust: species
Robinia pseudoacacia- hardness/oak-wood, false-acacia
Pokeweed: Diagnosis
History, evidence of ingestion
Cocklebur: species
Xanthium stumarium- yellow ?
Red Maple:
Acer rubrum- Sharp/cutting/the maple tree, red?
Horse tail & Bracken fern: treatment
Horsetail: species
Equisetum arvense- Horse fence/hedge, land/region/country
tough jointed reed with lots of silicate, not palatable
Nitrate Accumulators
CORN!!--nitrate accumulates in the stalks lower down and not in the kernels, one of the ways to reduce the nitrate in the feed is to cut higher up and then not let the cows graze the stalks.
Jimson weed
Avocado: toxic part
immature leaves and fruit
Rhododendron & Azalea
•Rhododendron & Azalea
•Common ornamental shrubs
•Uncommonly ingested by dogs, cats, pet birds
•Cardiac glycosides
Oleander/Rhododendron/Azalea: species
Oleander (Nerium oleander- the oleander), Rhododendron sp. (rhododendrons- rose/red tree & azaleas)
Mostly used as ornamentals
Black Locust: toxic part
All, including bark
Tobacco: diagnosis
History, evidence of ingestion, nicotine in stomach contents or urine
Poison Hemlock: toxin
Coniine- related to nicotine
White snakeroot: clinical signs
-All:Weakness, tremors, depression, collapse, coma, death. Can occur days to two weeks after ingestion, brought on by stress.
-Cattle: Also:Muscle fasiculations, can cause death, esp. of nursing calves. Passes through milk. Cows may not show signs if calves are nursing.
-Horses: Also:Sluggish, ataxia, throat paralysis (drop food), myocardial degeneration which can lead to death with no other signs.
-People: who drink affected cow milk can get sick and die (what Abraham Lincoln's mother may have died of)
Yew: prevention
Very preventable disease
Best thing is to educate the clients
Yew not EWE is what is poisonous!
Small animal poisonous plants
Araceae Family (Philodendron, dieffenbachia (Dumb-cane), caladium, Jack-in-the-Pulpit
Easter Lilly/ Tiger Lilly
Rhododendron & Azalea
Buckeye & Horsechestnut: toxic parts
All, contain aesculin
Poison Hemlock: clinical signs
•Signs: Salivation, gastroenteritis, excitement, resp. paralysis, death
•Teratogenic in swine and cattle -cleft palate, kinked tails, arthrogryposis
Sweetclover: toxin
dicoumarol (converted from coumarin by mold)
Ragwort: species
Senecio- old or six
Also called Groundsel
Nitrate: species affected
Ruminantes (who convert nitrate into the poisonous nitrite in the rumen)
Monograstrics exposed to nitrite directly
Nitrate: treatment
1% Methylene Blue
(4-15 mg/kg every 4-6 h)
Methylene blue has a higher affinity for nitrite than hemoglobin so will pull the nitrite off the blood cells converting methemoglobin back to hemoglobin allowing them to receive oxygen again. This can turn a sheep's brain blue
Fescue: Equine
Horses are very sensitive to the prolactin antagonistic effects of ergovaline and will suffer from prolonged gestation (370d vs. 336d), will have a thickened placenta that foal can't break through when born, will have abortions, and decreased milk, recommend not feeding fescue in the last third of pregnancy when prolactin is really ramping up and taking effect
Nightshade & Nettles: Diagnosis
History of ingestion
Pants in rumen
Solanine in rumen contents, tissues, urine
Oak: Prevention
Add Calcium hydroxide (CaOH) to feed to bind tannins and prevent them from being absorbed
Buckeye & Horsechestnut: signs
-Horses (single stomachs): GI irritation, diarrhea,
-Ruminants: (aesculin converted to aglycone in rumen) weakness, staggering, dyspnea, death
Ragwort: clinical signs
Rough hair coat, weight loss, depression, weakness, anorexia, icterus, ascites, bleeding, death (all related to chronic hepatic injury)
St. Johnswort: MOA
Hypericin is a primary photosensitizer so it is activated by ultraviolet light striking it when there is no melanin blocking the UV light and when it is close to the surface of the skin and can become excited by UV light. Its electron moves up an energy level, then the electron returns to its original level and releases heat causing a burn. Primary means liver is healthy, secondary is when liver is damaged and normal things are not being detoxified properly
Oleander/Rhododendron/Azalea: Toxin
Cardiac glycosides in all of plant. Interfere with electrical conductivity of heart.
Yew: toxic part of plant
All, except maybe the berries
Horse tail & Bracken fern: species affected
Rarely other livestock
Black Walnut: treatment
treat by removing the bedding and treating for laminitis
Porcine Hemorrhagic syndrome
-Seemed to be feed associated, all these pigs coming in with bleeding tendencies.
-Just start bleeding in the midwest
-Treatment with VitK worked!
-now supplement pig diets with Vit K and don't see anymore unless someone forgets why we supplement with vit K
Water Hemlock: toxic dose
Very small amounts can be toxic
St. Johnswort: toxic parts
all parts containing hypericin a primary photosensitizer
Nightshade & Nettles: species affected
at risk: cattle, sheep, horse, pigs, birds
Cyanogenic: Mechanism of action
Cyanide is found in cherry tree leaves. CN is very volitile and when the leave falls off the tree it is converted to an available form then very quickly starts off gasing. By the time the leaf is dry and crisp all of the cyanide should be gone. While leaf is still alive on the tree the CN should not be available
When animal ingests the CN it binds to heme in the electron transport chain (ETC) halting aerobic cellular respiration, this drastically reduces available ATP leading to sudden death! Die within a few minutes
Nitrate: Toxic dose
Forages with > 1% nitrate can be toxic
Red Maple: toxic part
wilted leaves in fall after frost, or after the tree has been damaged/ fallen down
fresh leaves- no toxicity
Redroot Pigweed: mechanism of action
oxalates are absorbed and first bind to calcium in the blood leading to decreased ionized calciuma and hypocalcemia. Later the CaOxalate crystals are depositied in the kidneys and cause massive necrosis
Why do animals eat poisonous plants?
Forced too!
bored and tied up to poisonous tree
fed hay with poisonous plants
first thing in the spring to come up green
last thing to turn brown in the fall
thrown trimmings from yew
most poisonous plants are unpalatable
Yew: Toxic dose
Toxic at 0.1% BWt
(a lb or less in an adult cow)
/ 118

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})


{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online