Toxicology (Yr 3) Flashcards
what are some neurotoxins?
deadly nightshade
hemlock
flatweed
bracken fern
mares tail
endophyte infected ryegrass
mouldy corn
botulism
blue-green algae
lead
what toxin does does deadly nightshade have in it?
tropane alkaloid (anticholinergic)
what are the clinical signs of deadly nightshade poisoning?
(atropine related)
mydriasis
shivering/spasms
tachycardia
dry mucous membranes
colic
haematuria
is there an antidote for deadly nightshade?
yes - neostigmine (easy to overdose)
how can hemlock be distinguished from cow parsley?
hemlock has irregular purple blotches on the stems
how does hemlock cause poisoning?
paralysing skeletal muscle motor nerve endings
what are the clinical signs of hemlock poisoning?
agitation, nervousness, twitching
seizures
salivation
dilated pupils
muscle weakness, cardiac abnormalities, breathing difficulty (die from this)
how does hemlock cause death?
paralysis of respiratory muscles
what are the clinical signs of flatweed similar to?
stringhalt (sudden hyperflexion of hindlimbs)
how is bracken fern toxic?
thiaminase activity (leads to vitamin B1 deficiency)
what are the clinical signs of bracken fern poisoning?
anorexia
cardiac dysrhythmias
crouched stance, arched neck
incoordination, convulsions
what is the pathogenesis of mares tail?
thiaminase (cause B1 deficiency)
what are the clinical signs of rye grass staggers (ergot)?
trembling, unsteadiness
erratic/anxious behaviour
how is rye grass staggers treated?
remove them from infected pasture
what causes botulism?
Clostridium botulinum
what are the clinical signs of botulism?
flaccid paralysis and dysphagia
what is the main sign of lead poisoning?
dysphagia
what are the clinical signs of lead poisoning?
peripheral nerve dysfunction
depression
laryngeal/pharyngeal paralysis
facial paralysis
blindness, seizures, death
what are the main cardio-respiratory toxins?
sorghum
foxglove
oleander
yew
rhododendron
monensin
what is monensin?
coccidiostat used in poultry
when does monensin poisoning occur in horses?
when horses eat chicken feed containing monensin
what are the main hepatotoxins of horses?
pyrrolizidine alkaloid containing plants
aflatoxins
what are the signs of liver failure from pyrrolizidine alkaloid toxicity?
weight loss
jaundice
dull/depressed
muscles tremors/weakness
yawning
inappetence
photosensitisation
neurological
what is the most common plant containing pyrrolizidine alkaloid?
ragwort
what is the main myotoxin?
sycamore
what are the clinical signs of sycamore poisoning?
weakness/fasciculations
recumbency
red urine
marked elevation of muscle enzymes
what is the main enterotoxin plant?
oak
what are the clinical signs of oak poisoning?
colic, tenesmus
haemorrhagic diarrhoea
how can you tell a horse has leukocytoclastic vasculitis rather than photosensitisation?
will be on the medial and lateral aspect of the limb (photosensitisation will mainly be on the lateral aspect)
