Toxicology Exam #1 Question with verified answers
Selenium Poisoning - √√lots of diseases - depends on form, duration, route, and
species
all species susceptible - horse most sensitive
*LA production animal problem due to supplementation*
What 5 toxins cause hypersensitivity to external stimuli? - √√bromethalin,
strychnine, metaldehyde, penitrem-A, chlorinated hydrocarbons
What are the five rodenticides? - √√anticoagulants, bromethalin, cholecalciferol,
strychnine, zinc phosphide
Acute Se Poisoning - √√severe pulmonary edema and necrosis (lung, heart,
nervous - swine)
Chronic Se Poisoning - √√loss of long hair of mane and tail (Bobtail disease)
Sources of Selenium Poisoning - √√forages (location driven) - accumulator plants
supplements - mixing errors, injectibles
water/contamination - i.e. Phosphorus mines
,Selenium Poisoning - Clinical Signs - √√vary between species and duration of
exposure
*multisystemic problem*
acute - *cardiac, lung (polo ponies), poliencephalomalacia - swine*
chronic - lame, rough hair coat, hair loss, anorexia, hoof deformities
Selenium Poisoning - diagnosis - √√history of exposure - source
clinical signs + lesions - vary based on species, dose, duration
analytically - blood (antemortem), liver (postmortem), source, hair/hoof (chronic)
Selenium Poisoning - treatment - √√symptomatic and supportive
variable prognosis
Selenium Deficiency - √√white muscle disease (ruminants, horses)
masseter muscle myopathy (tongue, esophagus, heart) - horse
Fescue Poisoning - √√large animals
,mycotoxin
*animals eating tall fescue with endophyte*
common problem in US
Fescue - MOA - √√several toxins - ergovaline is highest concentration
*peripheral vasoconstriction and suppression of prolactin secretion*
Fescue - clinical disease - √√summer - *summer slump* in cattle =
vasoconstriction, unable to dissipate heat - *hyperthermia, decreased feed
intake, abortions*
winter - *fescue foot* in cattle = vasoconstriction - *ischemic necrosis of distal
extremities*, abortions
anytime of year - *reproductive problems* in horses, cattle, sheep - *dysmature
foals, agalactia, abortions*
Fescue - diagnosis/treatment - √√*specific to three diseases*
history of ingesting tall fescue with endophyte
*test hay/urine for ergovaline*
, Tx = prevention, domperidone (dopamine antagonist)
Ergot Poisoning - √√mycotoxin
fungus invades grains, grasses and replaces seed with spore-producing structure
(*sclerotia body - ergot*)
problem in PNW - seed screenings
*looks like rodent feces*
Ergot - MOA - √√ergopeptide alkaloids (ergotamine, ergonovine) - amount varies
pelleted feeds are worse
cause vasoconstriction
all animals susceptible, but cattle and swine are historically affected
Ergot - clinical sigsn - √√feed refusal
dry gangrene - lameness
neurologic signs
Selenium Poisoning - √√lots of diseases - depends on form, duration, route, and
species
all species susceptible - horse most sensitive
*LA production animal problem due to supplementation*
What 5 toxins cause hypersensitivity to external stimuli? - √√bromethalin,
strychnine, metaldehyde, penitrem-A, chlorinated hydrocarbons
What are the five rodenticides? - √√anticoagulants, bromethalin, cholecalciferol,
strychnine, zinc phosphide
Acute Se Poisoning - √√severe pulmonary edema and necrosis (lung, heart,
nervous - swine)
Chronic Se Poisoning - √√loss of long hair of mane and tail (Bobtail disease)
Sources of Selenium Poisoning - √√forages (location driven) - accumulator plants
supplements - mixing errors, injectibles
water/contamination - i.e. Phosphorus mines
,Selenium Poisoning - Clinical Signs - √√vary between species and duration of
exposure
*multisystemic problem*
acute - *cardiac, lung (polo ponies), poliencephalomalacia - swine*
chronic - lame, rough hair coat, hair loss, anorexia, hoof deformities
Selenium Poisoning - diagnosis - √√history of exposure - source
clinical signs + lesions - vary based on species, dose, duration
analytically - blood (antemortem), liver (postmortem), source, hair/hoof (chronic)
Selenium Poisoning - treatment - √√symptomatic and supportive
variable prognosis
Selenium Deficiency - √√white muscle disease (ruminants, horses)
masseter muscle myopathy (tongue, esophagus, heart) - horse
Fescue Poisoning - √√large animals
,mycotoxin
*animals eating tall fescue with endophyte*
common problem in US
Fescue - MOA - √√several toxins - ergovaline is highest concentration
*peripheral vasoconstriction and suppression of prolactin secretion*
Fescue - clinical disease - √√summer - *summer slump* in cattle =
vasoconstriction, unable to dissipate heat - *hyperthermia, decreased feed
intake, abortions*
winter - *fescue foot* in cattle = vasoconstriction - *ischemic necrosis of distal
extremities*, abortions
anytime of year - *reproductive problems* in horses, cattle, sheep - *dysmature
foals, agalactia, abortions*
Fescue - diagnosis/treatment - √√*specific to three diseases*
history of ingesting tall fescue with endophyte
*test hay/urine for ergovaline*
, Tx = prevention, domperidone (dopamine antagonist)
Ergot Poisoning - √√mycotoxin
fungus invades grains, grasses and replaces seed with spore-producing structure
(*sclerotia body - ergot*)
problem in PNW - seed screenings
*looks like rodent feces*
Ergot - MOA - √√ergopeptide alkaloids (ergotamine, ergonovine) - amount varies
pelleted feeds are worse
cause vasoconstriction
all animals susceptible, but cattle and swine are historically affected
Ergot - clinical sigsn - √√feed refusal
dry gangrene - lameness
neurologic signs
