Selenium Flashcards
What is the most common cause of toxicity?
over supplmentation
plant source (locoweed, seleophiles)
injectable supplments
narrow margin of safety
What important processes are Se involved in?
glutathione peroxidase (can be used to assess) antioxidant properties
What is the absorption and metabolism?
organic and inorganic well absorbed
methylation is the primary form of metabolism
What is the distribution and excretion?
found in all tissues
oxidative and energy rich tissues highest level (liver/kidney)
can displace sulfur and detected in hoof and hair
accumulate in fetus
80% excreted in urine
- bile, sweat, lungs, hair and hooves also
What is the MOA?
results in lipid peroxidation and membrane damage
similar effects with Se deficiency
(must find out Se level)
high levels also reduce ATP formation and is an irritant
What are the signs of acute poisoning? what is likely to cause this?
massive oral injection
sudden 1-2d onset
death quickly
- anorexia, depression, dyspnea, cyanosis, colic, shock
What are the PM findings of acute poisoning?
congestion, hemorrhage, enteritis, degen changes in liver and kidney
What are the signs of subacute poisoning “blind staggers”?
days to weeks for onset wander aimlessly, anorexic and blind progress to weakness will respond to treatment if untreated umpared swallowing paralysis, head pressing, emaciation, dyspnea nd death
What are the PM findings for subacute poisoning?
pulmonary edema, hydrothorax, gastroenteritis, ulcers, rumen necrosis and hyperemia, degenerative and necrotic changes in liver and heart
consistant but doesnt prove
What are the signs of chronic poisoning (alkali disease)?
month in duration (onset)
dullness, rumen stasis, impaction, hoof deformities (swelling or coronary band and sloughing) and hair loss (tail)
feet susceptible to freezing
What is the PM findings for chronic poisoning?
mild gastroenteritis, atrophy, dilation of the heart and degen changes in most ograns systems
What is specific to chronic poisoning in pigs?
symmetrical spinal poliomalacia (necrosis of ventral grey horns causing paralysis) L7-L9)
continue to eat and treat
What is the Dx of Se?
tissue and feed analysis and patho
what is the Tx?
often unsuccessful
fluids for shock
acetylcysteine may be useful
dietary supplmentation with Cu, arsenic or sulfur containing amino acids (displaces)
