Anthrax & Toxins Flashcards
what causes anthrax, who is at risk, and when does this disease normally occur?
bacillus anthracis
herbivores most at risk
in summer, periods of hot and dry or hot and wet weather
what is the classic presentation of anthrax?
blood tinged fluid coming from all orifices and then dies suddenly
you go out to a farm to investiate a cow that suddenly died last night. When you get there, the cow is on the ground, appears bloated, and has blood coming from it’s mouth, ears, nose, and anus. What is your next step?
no NOT do a necropsy or cut into the animal and do NOT move the carcass
describe the life cycle of anthrax
when a cow with it dies, their tissues are full of bacteria, and if the carcass is opened and exposed to oxygen, these bacteria form indistructible spores. these spores are produced when the bacteria sense an environmental change, they can survive for decades, can be spread by scavengers, and are hydrophobic. Ultimately, the organism survives in the soil for years.
how do we think cows get exposed to anthrax?
anything that causes surface soil disturbance like construction or cattle walking into receeding water holes. they ingest the spores and they reactivate in the gut. potent toxins kill the animal within hours.
what is the ideal anthrax environment?
likes alkaline soil >6 pH, likes warm temps >15.5, and it likes receding flood waters
how do you diagnose anthrax?
do not open the carcass! sample the blood, look at it under the microscope, look for trains or organisms, and do a SNAP test
how are anthrax carcasses disposed of?
incineration or deep burial if no other option
when should you suspect a toxicosis?
acute illness in group of animals, similar signs of similar severity with all animals, signs appearing after a shared event (such as medication, feed change, or location change)
T or T: if you suspect a toxicosis, you can submit a poison screen test
false! there is no such thing
if you suspect a toxicosis, what kinds of samples are useful to collect?
feed, bedding, water
serum, whole blood, urine, ocular fluid
liver, kidney, brain, spinal cord, lungs, heart, spleen, intestines, bone
the 3 organs most commonly affected by organs are
brain, liver, kidney
name the antidotes for the following toxins:
lead, nitrate, organophosphate, cyanide, botulism/snake bitea
lead: EDTA and thiamine
nitrate: methylene blue
organophosphate: atropine
cyanide: sodium thiosulfate
botulism/snake bites: anti-toxin
mechanism of lead toxicity
decreased heme synthesis, interfere with GABA, calcium, and Na/K ATPase pumps all leading to altered nerve and muscle transmission
you are presented with a group of calves that are ataxic, teeth grinding, muscle tremors, and appear blind. when you walk the property there is an old car in the pasture. how will you confirm your top differential?
lead toxicosis
for a live calf: whole blood EDTA tube to check lead levels
for dead calves: liver, kidney, and brain (fixed and fresh)
feed or suspected source samples
