Garden/Ornamental Plants Flashcards
What is the toxic agent of foxglove? which part of plant?
multiple cardiac (digitalis) glycosides - digitoxin, digoxin, gitoxin
flowers, seeds or leaves
What is the MOA of glycosides in foxglove?
interfere with NA/K ATPase -> decrease intracellular K -> increase intracellular NA -> increase Ca
interfere with normal electrical conductivity in myocardium (block)
What is the toxic level of foxglove?
high (only need a small amount)
What species is foxglove poisonous to?
all species at risk
drying increases palatability but not toxicity
what are clinical signs of foxglove poisoning?
signs in 5-24h GI signs predominate early - vomiting, colic, diarrhea, anorexia CV signs - bradycardia, arrhythmias, block weakness, depression, dyspnea, tremors -> convulsions, coma, death
What is the Dx of foxglove?
clinical signs, Hx, pathology
can send blood to human doctor to test digoxin levels
blood work: hyperkalemia
What is the treatment for foxglove?
Aggressive Gi decontam AC and saline cathartic GL S&S (fluids, treat hyperkalemia and arrhythmia) digibind (antitoxin) - human hospital, expensive
What is the toxin in japanese yew? what part of the plant?
alkaloid taxine (alkaloids)
wood, bark, leaves, seeds (chewed)
fruit is not
What is the MOA of alkaloids for japanese yew?
disrupts Na/Ca currents in myocytes
depresses conduction (depolarization)
cardiac arrest
What is the toxicity/conditions of the japanese yew?
green foliage (0.5g/kg to) to equids
toxic to ruminants at 5g/kg
all species at risk
all parts toxic (dried or fresh)
What are the clinical signs of japanese yew poisoning?
sudden death (horse within 15min)
weakness, trembling, dyspnea, bradycardia, arrhythmias, convulsions, collapse, coma
death from cardiac arrhythmias
what is the Dx of japanese yew?
clinical signs ECG abnormality (wide QRS and small P wave) history alkaloid screen lesions non-specific
What is the Tx for japanese yew?
aggressive GI (rumenotomy, GL)
AC, cathartic, IV fluids
S&S care
ventilator (dogs)
What is the toxic agent in rhododendron? where is it in the plant?
glycoside grayanotoxin (andromedotoxin)
all parts, esp leaves
What is the MOA of glycoside for rhododendron?
toxin binds to Na channels –> influx of Na –> prolonged myocardial depolarization
increased intracellular Ca
What is the toxicity/conditions of rhododendron?
0.2% BW of leaves 3ml of nectar ruminants most common (rare horses) leaves not palatable (only 2-3 toxic) evergreen risk
What are the clinical signs of rhododendron?
appear within 6h acute GI upset - salivation, vomiting, diarrhea, anorexia CNS depression - weakness, ataxia, paralysis CV - bradycardia, hypotension, arrhythmias (AV block) death
What is the Dx for rhododendron?
clinical signs, history, pathology
What is the Tx for rhododendron?
GI decontam
AC and saline cathartic
S&S care
What is the toxic agent of Jimson weed? What part of the plant?
tropane alkaloids
- hyoscyamine (atropine isomer), scopalamine and hyoscine
all parts, esp seeds
what is the MOA of tropane alkaloids in Jimson weed?
low doses: competitive inhibition of acetylcholine
high doses: direct CNS stim
what is the toxicity level/conditions of Jimson weed?
very little amounts in horses, pigs and cattle?
green plant palatable (increases with herbicide treatment)
contaminated feed
What are the clinical signs of Jimson weed?
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
What is the pneumonic to remember symptoms of Jimson weed?
red as a beat (vasodilation)
dry as a bone (decrease secretions)
blind as a bat (pupil dilation)
mad as a hatter (hallucinations in people)
What is the Dx of Jimson weed?
clinical signs, history, bioassay, pathology
What is the treatment for Jimson weed?
Gi decontam
AC, saline cathartic
S&S care
What is the toxic component in Caster Beans? what part of the plant? (hint: breaking bad)
glucoprotein ricin
leaves and esp seeds
What is the MOA of ricin in Caster Beans?
binds to galacto-lipid and galacto-protein membrane components - internalization
causes cell death by inhibition of protein synthesis (damages ribosomes)
what is the toxicity/conditions of Caster Bean?
rabbit - 40ug/Kg
horse - 0.01% BW of beans
ruminants - less sensitive
dogs - 1-3 beans
alls species
usually seeds requried
What are the clinical signs of Caster Beans?
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
What is the Dx of caster bean poisoning?
clinical signs history clin path - looks like panleukopenia with left shift - looks like shock - liver enzymes up - bilirubin up - decrease sugar lesions
What is the treatment for Caster Beans?
AC, GI decontam, S&S
delayed onset so likely passed
aggressive supportive care
- fluids, balance electrolytes, GI protectants
