Poisonous Plants - Exam 2 Part 3

Question 1

What are the 3 primary toxins associated with locoweed (Astragalas and oxytropis)?

Answer 1

Swainsonine
Miserotoxins
Se accumulators

Question 2

How is swainsonine produced and what is its mechanism of action?

Answer 2

Produced by endophyte Embellisia

MOA: inhibits alpha mannosidase & golgi mannosidase II → lysosomal storage disease

Question 3

What are the clinical syndromes associated with swainsonine poisoning in locoweed?

Answer 3

“Locoism” - CNS signs
repro failure
poor growth (mimics BVDV)
CHF due to high altitude hypoxia
lowered immune response

Horses – depression, incoordination, staggering gait, unpredictable behavior - HORSES DO NOT RECOVER

Question 4

How might swainsonine poisoning be diagnosed?

Answer 4

Plant, serum, decreased alpha-mannosidase (6 days), elevated AP, AST, LDH, reduced thyroid or serum protein, cytoplasmic vacuoles in lymphocytes

Post-mortem – cellular vacuolization, stomach ulcers, thyroid hypertrophy

Question 5

Sage poisoning – Clinical signs, toxins

Answer 5

monoterpene in horses, sesquiterpene lactones in other spp

Clinical signs: breath/feces smell of sage, CNS signs, non-specific degenerative encephalopathy - HORSES RECOVER

Question 6

What are 2 common plants associated with chewing disease? Clinical signs?

Answer 6

Russian Knapweed and Yellow Star Thistle

Clinical signs: hypertonicity of facial & tongue mm, inhalation pneumonia, circling, head tossing, dehydration, starvation lead to death, nigropallidalencephalomalacia

Question 7

What areas of the brain are necrotic in the Nigropallidalencephalomalacia that are the classic lesions in chewing disease?

Answer 7

globus pallidus
substantia nigra

Question 8

Name 2 plants that contain a thiaminase that result in thiamine deficiency.

Answer 8

Bracken Fern
Horsetail

Question 9

Name the other primary toxin in Bracken Fern?

Answer 9

Ptaquiloside

Question 10

Describe the disease syndromes associated with bracken fern poisoning (This is best described in the Notes pdf)

Answer 10

Polioencephalomalacia
acute hemorrhage
progressive retinal degeneration in sheep
bladder/upper GI cancer “enzootic hematuria in cattle”

Question 11

Describe the MOA of nicotine and nicotine-like alkaloids.

Answer 11

nicotinic ACh receptor agonists → reduced fetal movement

Question 12

Describe the Clinical signs – early and late phases of nicotine and nicotine-like alkaloids.

Answer 12

Early phase clinical signs: abd pain, hypertension, tachycardia, miosis, tremors

Late phase clinical signs: hypotension, bradycardia, dyspnea, mydriasis, coma, resp failure

Question 13

Describe the treatment of the nicotine and nicotine-like alkaloids.

Answer 13

cathartics
activated charcoal
atropine
IV fluids

Question 14

List 4 plants associated with “crooked calf disease”

Answer 14

Tobacco
Poison Hemlock
Lupines
Locoweeds

Question 15

What is the MOA for teratogenesis for tobacco, poison hemlock, lupines and locoweeds?

Answer 15

MOA: neuromuscular blockade and decreased fetal movement

Question 16

when is the window of opportunity for cleft palate from tobacco, poison hemlock, lupines and locoweeds?

Answer 16

30-50 days for cleft palate,

Question 17

when is the window of opportunity for MCC for tobacco, poison hemlock, lupines and locoweeds?

Answer 17

50-100 days for multiple congenital contractures “crooked calf disease”

Question 18

Fabaceae family and principal toxins.

Answer 18

Quinolizidine Alkaloid Cytisine

Golden banner, golden chain tree, scotch broom, mescal bean, kentucky coffee tree, american coffee berry, kentucky mahogany

Question 19

Describe the 3 poisoning syndromes associated with lupines.

Answer 19

Acute neurotoxic syndrome
Teratogenic
Lupinosis

Question 20

Cyclopia in sheep and cattle is associated with what teratogenic plant?

Answer 20

western false hellebore, skunk cabbage, corn lily (Veratrum spp)

Question 21

What is its mechanism of action for Veratrum spp (western false hellebore, skunk cabbage, corn lily)?

Answer 21

cyclopamine & cyclopasine inhibits hedgehog signaling pathway during embryonic development

Question 22

What are the windows for damage of cyclopia and tracheal agenesis/cleft palate/short legs?

Answer 22

Cyclopia 13-14th day of gestation

Tracheal agenesis, cleft palate, short legs 30-35th days of gestation

Question 23

Nitrate poisoning associated abortion occurs at what stage in pregnancy? How is it diagnosed?

Answer 23

Any stage of pregnancy

Diagnosis: > 40 ppm nitrate/ml fetal ocular fluid

Question 24

Pine needle abortion toxin and MOA

Answer 24

isocupressic acid

inhibits uterine blood flow causing fetal stress and premature parturition

Question 25

what species are most commonly observed with pine needle abortion

Answer 25

cattle and bison

Question 26

what is broom snakeweed associated with

Answer 26

liver and kidney disease
abortion

Question 27

what plant produces Gossypol?

Answer 27

cottonseed

Question 28

what animals are most susceptible to Gossypol’s effects?
least susceptible?

Answer 28

monogastrics (pigs) or calves on starter rations

females less effected
mature cows least