Toxicology Flashcards
Oleander toxicity signs
Cardiac arrhythmias Colic, diarrhea, anorexia General malaise Azotemia
Type of flower that oleander is, where is it more commonly found and what is the name of the toxins that it contains?
It’s an Apocynaceae Found in southern and western US Toxins include cardenolides, and cardiac glycosides (oleandrin and nerine)
What is the mechanism of action of the cardiac glycosides?
Inactivate K and Na ATPases in plasma membranes of cardiac myocytes. This increases Na concentration intracellularly and K extracellularly. ^ Na intracel increase the influx of Ca in the cell by inhibiting Na-Ca channels. Cardenolides may inhibit efflux of Ca from the cells. Increased intracel Ca increases the resting membrane potential and cause spontaneous cell depolarization, leading to a positive inotropic effect, followed by development of abnormalities in electrical conductivity of the myocardium, arrhythmias and loss of myocardial contractility
Cattle grazing on fescue pastures can commonly develop all of the following except:
a. Gangrene
b. Fat necrosis
c. Hyperthermia
d. Perinatal agalactia
d. Perinatal agalactia
Cattle have a placental lactogen that can prevent agalactia in the perinatal period, but may experience 50% drop in milk production after that period is over.
Name the endophyte/ s and type of grass infected that can cause hyperthermia during hot environmental conditions in cattle. (Summer slump)
It’s an ergopeptine alkaloid toxicosis with Neotyphodium coenophialum in tall fescue grass and Claviceps purpurea in perennial ryegrass (western US)
Which of the following should be administered as an antidote for an organophosphate toxicity??
a. 4-methylpyrazole (4-MP)
b. Calcium EDTA
c. Pralidoxime chloride (2-PAM)
d. Meso-2.3 dimercaptosuccinic acid (DMSA)
c. Pralidoxime chloride (2-PAM)
Which of the following is an appropriate treatment for quinidine toxicity?
a) Activated charcoal
b) Digoxin
c) Magnesium sulfate
d) Sodium bicarbonate
d) Sodium bicarbonate
Which compounds is the toxic principle found in Black Walnut trees
a) Juglone
b) Swaisinone
c) Grayanotoxin
d) Oleandrin
a) Juglone
A horse was found down in a pasture that consists mainly of dirt and this plant:
There were also several sheep grazing in the pasture that were unaffected. What is the most likely reason for the species differences in disease?
a) Small ruminants lack the ability to biotransform to methemoglobin.
b) Small ruminants lack the ability to biotransform to quinolizidine.
c) Small ruminants lack the ability to biotransform to tannins.
d) Small ruminants lack the ability to biotransform to pyrroles.
d) Small ruminants lack the ability to biotransform to pyrroles.
Which one of the following toxins acts by uncoupling oxidative phosphorylation?
A. Pyrethrin
B. Amitraz
C. Bromethalin
D. Strychnine
C. Bromethalin
Bromethalin, is a nonanticoagulant, single-dose rodenticide. Is a neurotoxin available as bars (blocks), pellets, seed, and worm. Mole baits are sold as worm containing 0.025% bromethalin, whereas rat and mouse baits contain 0.01% bromethalin. Bromethalin and its main metabolite desmobromethalin are strong uncouplers of oxidative phosphorylation. This results in intra-myelin fluid accumulation, leading to long nerve demyelination and intra-myelin cerebral edema. The net result is cerebral and spinal edema and increased CSF pressure, leading to neurologic dysfunction.
Which of the following is false regarding organophosphate toxicity?
A. Toxicity is due to inhibition of acetylcholinersterase, resulting in an increase in synaptic acetylcholine and overstimulation of muscarinic and nicotinic receptors
B. Acetylcholinersterase enzyme inhibition by OPs is esentially irreversible if untreated or if treatment is delayed due to acectylcholinersterase-OP complex aging
C. Overstimulation of the nicotinic receptors causes SLUDD(E) signs: salivation, lacrimation, urination, defecation, dyspnea and emesis
D. OPs are easily absorbed through the skin due to the fat soluble nature of the compounds
C. Overstimulation of the nicotinic receptors causes SLUDD(E) signs: salivation, lacrimation, urination, defecation, dyspnea and emesis
What is the mechanism of action of the cardiac glycosides?
a. Inhibit membrane Na+-K+-ATPase pumps
b. Decrease cardiac contractility by increasing Ca++ excretion out of the cell
c. Increase potassium inside the cell, leading to increase action potential
d. Inhibit normal sodium and calcium exchange across myocardial cells
a. Inhibit membrane Na+-K+-ATPase pumps
You are called to examine a group of 43 cattle with important mortality in the last days. The cows were moved to a new pasture yesterday and since, 35 of them died within 4 hours of showing clinical signs. Those who survived or initially found alive were in lateral recumbency with muscle tremor, jugular distension and sign of dyspnea. What is the most likely cause of death in this group of cows?
a. Yew poisoning
b. Buttercup toxicity
c. Russian knapweed toxicity
d. Poison hemlock poisoning
a. Yew poisoning
Which toxin can lead to Cor pulmonale in beef cattle?
a. Swaisonine
b. Ptaquiloside
c. Ergovaline
d. Nitro-toxin
a. Swaisonine
