Quiz Flashcards
1
Q
Neurotoxicants
Organophosphate pesticides
A
- MOA Irreversible inhibition of AChE => cholinergic overstimulation
- CS Muscarinic:
- SLUDGE-M
- Nicotinic muscle fasciculations face
- Horses => colic, dehydration
- Cattle => rumen stasis; NOT MIOSIS + sheep => depression
- Dogs/Cats => CNS progressing to convulsions
- Chlorpyrifos => more severe nicotic signs in cats (muscarinic tolerance)
- DX: Atropine test
- TX:
- GI decon
- Atropine Oximes => reactivates AChE
- Diazepam, barbiturates
- OPIDN (OP-induced delayed nurotoxicity) motor neuron degeneration no tx
2
Q
Neurotoxicants
Ivermectin
A
- Soil fungus: stretomyces avermitilis
- Dewormer/antihelminth in cattle
- MOA: GABA-A receptor agonist; inc GABA release
- CS
- Ataxia, disorientation, lethargy, mydriasis, coma, bradycardia
- DX
- HX of admin
- measured in GI, liver, fat, feces
- TX:
- GI dcon (act charcoal)
- epinephrine
- seizure: short acting barbiturates (NOT BENZOS)
- supportive care
3
Q
Neurotoxicants
Rodenticides (3)
A
- Bromethalin: parent and metabolite uncouple oxidative phosphorylation in CNS
- Nicotine: stimulate then block nicotinic ACh receptor
- Metaldehyde:
- fuel for small heaters, molluscicide
- metabolism converts to acetaldehyde => CNS excitation
4
Q
Neurotoxicants
Mycotoxin: Slaframine
A
- Black patch fungus on red clover
- MOA
- ACh mimic; primarily muscarinic cholinergic agonism, esp exocrine glands
- CS
- slobbers, bloat, diarrhea, frequent urination, feed refusal
- DX
- consumption of clover with black fungus
- DDX
- OPs, Botulism
- TX
- Remove source, maintain hydration and electrolytes,
- Atropine,
- rarely fatal
- Clinical signs resolve 48 hours after last exposure
5
Q
Neurotoxicants
Mycotoxin: Fumonisin
A
- Metabolite of fusarium from corns with stars
- MOA
- Inhibits sphingosine-N-Acetyltransferase => inc sphinganine => cytotoxic
- CS
- PPE
- inc RR, dec HR, pulmonary edema, resp distress, open mouthed breathing, death *
- pigs usually recover if feed is removed
- ELEM
- target brain and liver
- hyperexciteability, anorexia, ataxia, circling, drowsiness, blindness
- nearly 100% fatal
- PPE
6
Q
Neurotoxicants
Tremorgenic mycotoxins
A
- Penicillin, Aspergillus, Claviceps
- From food, stored grains/nuts, forage, garbage, compost
- MOA
- Release of neurotransmitters from synaptosomes in CNS
- CS
- diminished activity, immobility, hyperexciteability, m. tremor, ataxia, tetanic seizure
7
Q
Neurotoxicants
Ammoniated feed toxicosis
A
- Non protein nitrogen sources (urea, ammonium salts) imidazoles
- MOA: ?
- CS bovine bonkers, excitability, rapid blinking, alternate between excited and normal
- DX
- HX of exposure, CS, food/rumen analysis
- DDX
- OP pesticides, cyanide, grain overload, meningitis, encephalitis
- TX
- Feed removal
- 5-10 gallons cold water plus 1 gallon vinegar
8
Q
Neurotoxicants
Strychnine
A
- Seeds of strychnos-nux vomica, alkaloids to control pocket gophers
- Often used as a malicious poison
- MOA
- competitive antagonist at post-synaptic spinal cord and medulla for glycine receptors => muscle disinhibition
- CS
- rapid onset, little to no vomiting
- anxiety to restlessness to stiff neck and gait to violent seizures from external stimuli
- Death from respiratory failure and asphyxiation/exhaustion
- saw horse stance
- DX
- CS, sizure, sawhorse
- DDX
- other seizure causing things
- TX
- aggressive
- Control seizures: Phenobarb or methocarbamol
- prevent asphyxiation
- emesis, gastric lavage
- ion-trapping if not acidotic: ammonium chloride
- Bicarb for acidosis
9
Q
Neurotoxicants
Salt toxicity
A
- Usually from dehydration
- MOA
- diffusion of Na into CSF
- when serum Na lowers, water diffuses into CSF
- CS
- CNS, salivation, inc thirst, abdominal pain, diarrhea
- DX
- serum Na levels
- TX
- lower plasma Na by 0.5-1mEq/L/hr
- loop diuretics
10
Q
Neurotoxicants
Pharmaceuticals: Xanax (Alprazolam)
A
- Benzo
- MOA
- works on limbic, thalamic, hypothalamic CNS
- CS
- ataxia, depression, tachycardia, diarrhea, ptylism
- TX
- Flumazenil
- GI decon, support
11
Q
Neurotoxicants
Pharmaceuticals: Ambien (Zolpidem)
A
- Bezo-like
- MOA
- binds to benzo omega-1 receptor
- CS
- ataxia, vomiting, lethargy
- TX
- supportive, symptomatic
12
Q
CV and Hem tox
Rodenticides
A
- MOA
- inhibits vitamin K1 epoxide reductase
- prevents the formation of vit K dependent clotting factors (2, 7, 9, 10)
- CS
- hemorrhage, coagulopathies, depression, anorexia, anemia
- DX
- History of exposure, coagulopathy, response to vit K, clotting tests
- TX
- emetic, absorbant, cathartics, vit K, transfusion
- 1st gen: warfarin, short half life, low potency
- 2nd gen: brodifacom, long half life, high potency
13
Q
CV and Hem tox
Nitrate toxicosis
A
- Fertilizers, many plants, contaminated water
- Pigs > cattle > sheep > horses
- MOA
- nitrate to nitrite => vasodilation and oxidized ferrous => methemoglobin CS
- cyanosis, brown MM, ataxia, seizures, coma, death
- DX
- nitrate levels feed/water
- TX
- methylene blue
- cats and horses = ascorbic acid
- cattle = feed corn
14
Q
CV and Hem tox
Cardiac glycosides
A
- Ornamental plants
- MOA
- Inhibits Na/ATPase pump through competition with K for binding sites
- CS
- 1hr to weeks after ingestion
- trembling, staggering dyspnea
- Inc Ca and intracellular Na
- racing HR, arrhythmias, weak pulse
- hyperkalemia
- DX
- hx of access, CS, analysis of vomitus
- TX
- GI decon
- DIGOXIN
- arrhythmias: propranalol
- hyperkalemia: diuretics
15
Q
CV and Hem tox
Cyanide tox
A
- Wild cherry, white clover, fresh sorghum, fertilizers, pesticides, rodenticids
- DRY: NON-TOXIC
- Hydrogen cyanide: VOLATILE
- MOA
- inhibition of cytrochrome C oxidase
- blocks mitochondrial function and cell respiration
- CS
- cherry red, non-clotting blood
- sudden death, dyspnea
- DX
- HX, cherry red, non-clotting blood, frozen stomach contents
- TX
- Sodium nitrite => induces methemoglobinemia
- Sodium Thiosulfate
