Garden/Ornamental Plants

Question 1

What is the toxic agent of foxglove? which part of plant?

Answer 1

multiple cardiac (digitalis) glycosides
- digitoxin, digoxin, gitoxin

flowers, seeds or leaves

Question 2

What is the MOA of glycosides in foxglove?

Answer 2

interfere with NA/K ATPase -> decrease intracellular K -> increase intracellular NA -> increase Ca
interfere with normal electrical conductivity in myocardium (block)

Question 3

What is the toxic level of foxglove?

Answer 3

high (only need a small amount)

Question 4

What species is foxglove poisonous to?

Answer 4

all species at risk

drying increases palatability but not toxicity

Question 5

what are clinical signs of foxglove poisoning?

Answer 5

signs in 5-24h
GI signs predominate early
- vomiting, colic, diarrhea, anorexia
CV signs
- bradycardia, arrhythmias, block
weakness, depression, dyspnea, tremors -> convulsions, coma, death

Question 6

What is the Dx of foxglove?

Answer 6

clinical signs, Hx, pathology
can send blood to human doctor to test digoxin levels
blood work: hyperkalemia

Question 7

What is the treatment for foxglove?

Answer 7

Aggressive Gi decontam
AC and saline cathartic
GL
S&S (fluids, treat hyperkalemia and arrhythmia)
digibind (antitoxin)
- human hospital, expensive

Question 8

What is the toxin in japanese yew? what part of the plant?

Answer 8

alkaloid taxine (alkaloids)
wood, bark, leaves, seeds (chewed)
fruit is not

Question 9

What is the MOA of alkaloids for japanese yew?

Answer 9

disrupts Na/Ca currents in myocytes
depresses conduction (depolarization)
cardiac arrest

Question 10

What is the toxicity/conditions of the japanese yew?

Answer 10

green foliage (0.5g/kg to) to equids
toxic to ruminants at 5g/kg
all species at risk
all parts toxic (dried or fresh)

Question 11

What are the clinical signs of japanese yew poisoning?

Answer 11

sudden death (horse within 15min)
weakness, trembling, dyspnea, bradycardia, arrhythmias, convulsions, collapse, coma
death from cardiac arrhythmias

Question 12

what is the Dx of japanese yew?

Answer 12

clinical signs
ECG abnormality (wide QRS and small P wave)
history
alkaloid screen
lesions non-specific

Question 13

What is the Tx for japanese yew?

Answer 13

aggressive GI (rumenotomy, GL)
AC, cathartic, IV fluids
S&S care
ventilator (dogs)

Question 14

What is the toxic agent in rhododendron? where is it in the plant?

Answer 14

glycoside grayanotoxin (andromedotoxin)

all parts, esp leaves

Question 15

What is the MOA of glycoside for rhododendron?

Answer 15

toxin binds to Na channels –> influx of Na –> prolonged myocardial depolarization
increased intracellular Ca

Question 16

What is the toxicity/conditions of rhododendron?

Answer 16

0.2% BW of leaves
3ml of nectar
ruminants most common (rare horses)
leaves not palatable (only 2-3 toxic)
evergreen risk

Question 17

What are the clinical signs of rhododendron?

Answer 17

appear within 6h
acute GI upset
- salivation, vomiting, diarrhea, anorexia
CNS depression
- weakness, ataxia, paralysis
CV
- bradycardia, hypotension, arrhythmias (AV block)
death

Question 18

What is the Dx for rhododendron?

Answer 18

clinical signs, history, pathology

Question 19

What is the Tx for rhododendron?

Answer 19

GI decontam
AC and saline cathartic
S&S care

Question 20

What is the toxic agent of Jimson weed? What part of the plant?

Answer 20

tropane alkaloids
- hyoscyamine (atropine isomer), scopalamine and hyoscine

all parts, esp seeds

Question 21

what is the MOA of tropane alkaloids in Jimson weed?

Answer 21

low doses: competitive inhibition of acetylcholine

high doses: direct CNS stim

Question 22

what is the toxicity level/conditions of Jimson weed?

Answer 22

very little amounts in horses, pigs and cattle?

green plant palatable (increases with herbicide treatment)
contaminated feed

Question 23

What are the clinical signs of Jimson weed?

Answer 23

atropine like syndrome (mydriasis, thirst, colic, anorexia, tachycardia, rapid pulse, tachypnea, hypothermia, delirium, tremors, excitability, convulsions, recumbancy, coma, death from resp paralysis
horse - intestinal stasis
cow - bloat

high dose syndrome: hyperesthesia, apprehension, mania, vocalization

death common in livestock, rare in small animal

Question 24

What is the pneumonic to remember symptoms of Jimson weed?

Answer 24

red as a beat (vasodilation)
dry as a bone (decrease secretions)
blind as a bat (pupil dilation)
mad as a hatter (hallucinations in people)

Question 25

What is the Dx of Jimson weed?

Answer 25

clinical signs, history, bioassay, pathology

Question 26

What is the treatment for Jimson weed?

Answer 26

Gi decontam
AC, saline cathartic
S&S care

Question 27

What is the toxic component in Caster Beans? what part of the plant? (hint: breaking bad)

Answer 27

glucoprotein ricin

leaves and esp seeds

Question 28

What is the MOA of ricin in Caster Beans?

Answer 28

binds to galacto-lipid and galacto-protein membrane components - internalization
causes cell death by inhibition of protein synthesis (damages ribosomes)

Question 29

what is the toxicity/conditions of Caster Bean?

Answer 29

rabbit - 40ug/Kg
horse - 0.01% BW of beans
ruminants - less sensitive
dogs - 1-3 beans

alls species
usually seeds requried

Question 30

What are the clinical signs of Caster Beans?

Answer 30

patent period of 10h to several days
initial GI: severe colic, diarrhea (+/-blood), dehydration, depression, thirst, sweating, weakness, fever, pronounced heart beat, cyanosis, convulsions, recumbency -> coma
death from resp paralysis
degen of liver and kidney
resp and circ collapse from hypovolemic shock

Question 31

What is the Dx of caster bean poisoning?

Answer 31

clinical signs
history
clin path
- looks like panleukopenia with left shift
- looks like shock
-  liver enzymes up
- bilirubin up
- decrease sugar
lesions

Question 32

What is the treatment for Caster Beans?

Answer 32

AC, GI decontam, S&S

delayed onset so likely passed
aggressive supportive care
- fluids, balance electrolytes, GI protectants