what toxin is contained in larkspur?
what toxin is contained in poison hemlock?
piperidine alkaloids, poison hemlock resembles parsley
what toxin is contained in lupines?
what toxin is contained in tobacco?
where are diterpene, piperidine, and pyridine alkaloids found?
larkspur, poison hemlock, lupines and tobacco - these all contain nicotinic alkaloids
how to diterpene, piperidine and pyridine alkaloids act? (mechanism)
initial stimulation followed by persistent suppression of cholinergic and nicotinic receptors
clinical signs of diterpene, piperidine and pyridine alkaloid toxicity?
stimulatory - nervous, excitability, stiff gait, and trembling; GI shows salivation, diarrhea, vomiting and colic
suppression - weakness, collapse, death from resp paralysis
teratogenesis - subclinical ingestion by mother may lead to teratogenesis
postmortem signs of diterpene, piperidine and pyridine alkaloid toxicity?
nonspecific - congestion/hemorrhages in various organs, birth defects
how to treat diterpene, piperidine and pyridine alkaloid toxicity?
remove source, decontamination, atropine to control PS effects, limit handling prognosis is good if symptoms don't progress to respiratory paralysis
how to manage/prevent diterpene, piperidine and pyridine alkaloid toxicity?
ensure adequate alternate feed, avoid feeding garden waste, goats may develop a "taste" for poison hemlock
what toxic agent is located in Jimsonweed?
tropane alkaloids - atropine, scopolamine, hyoscyamine (highly potent)
all parts of the plant are toxic, especially the seeds
physical characteristics of Jimsonweed?
unpleasant smell, trumpet flowers, spiny seedpods
how does Jimsonweed work? (mechanism)
tropane alkaloids (atropine, scopolamine, hyoscyamine) are parasympatholytic(inhibits rest and digest) - they competitively antagonize the central and peripheral muscarinic Ach receptors
clinical signs of Jimsonweed toxicity?
tropane alkaloids (atropine, scopolamine, hyoscyamine) - red as a beet (vasodilation), dry as a bone (stop sweating), blind as a bat (lack of accommodation), mad as a hatter (CNS effects) and hot as a hare (poor thermoregulation)
postmortem lesions of Jimsonweed toxicity?
nonspecific, plant material may be present in GIT because they die so fast
treat Jimsonweed toxicity?
parasympathetic drugs (pilocarpine) don't work, use benzodiazepines and barbiturates for seizures
prevent Jimsonweed toxicity?
prevent hay contamination, ensure adequate alternative feed
what toxic agent is found in Riddell's ragwort and Arrowhead rattlebox?
pyrrolizidine alkaloids - toxic metabolites formed in liver
what toxic agents are found in arrowhead rattlebox?
pyrrolizidine alkaloids, also monocrotaline - causes fibrosing alveolitis and laminitis
how do Riddell's ragwort and Arrowhead rattlebox cause toxicity? (mechanism)
pyrrolizidine alkaloids - pyrroles formed in the liver, they cause DNA damage, cross-linking of proteins, amino acids and glutathionine
what are the clinical signs of pyrrolizidine toxicity?
acute - liver failure, photosensitization, behavioral changes, anorexia
chronic - weight loss, CNS signs (stargazing)
postmortem lesions of pyrrolizidine toxicity?
liver with edema, congestion, accentuated lobulation (fibrosis/cirrhosis in chronic cases), centrilobular degeneration ad necrosis, petechiation and edema of lungs/abomasal folds
treatment for pyrrolizidine alkaloids?
no specific treatment, poor prognosis, effects may occur 4-6 weeks post-exposure
how to prevent pyrrolizidine alkaloids?
prevent hay contamination, adequate alternate feed, avoid exposing young/naive
what part of yew is toxic? what is the toxin?
taxine alkaloids in all parts of yew, except the fleshy red aril of ripe fruit
how does yew cause toxicity?
yew contains taxine alkaloids that inhibit Ca and Na currents across cardiac muscle membranes - slows ventricular muscle contraction
clinical signs of yew toxicity?
taxine alkaloids cause sudden death due to peracute heart failure
postmortem lesions of yew toxicity?
no specific lesions, may see chewed leaves/twigs in rumen
how to treat yew toxicity?
no specific treatment, usually found dead, avoid disturbance and handling, might recover on their own
how to prevent yew toxicity?
don't feed garden waste to your cows