SA toxicology Flashcards
what needs to be stabilised in suspected toxin ingestion cases?
respiratory CV CNS thermoregulation electrolyte/acid-base derangement
if there has been topical exposure of a sticky toxic substance, what should be done?
clip animal or wash with vegetable oil
how should the eye be irrigated in cases of topical exposure to toxins?
saline/tepid water for 20 minutes
treat ulceration
what is the aim of treating ingested toxins?
decrease absorbed dose - prevent absorption, bind toxin, increase elimination
what can be used to induce vomiting in dogs?
apomorphine
what can be used to induce vomiting in cats?
xylazine or dexmedetomidine
what can be done prior to inducing vomiting to aid emesis?
feed small amount of food/water
what are the contraindications for inducing emesis?
already vomiting absent gag reflex sedated/unconscious seizing corrosive substance ingested
how fast after ingestion should emesis be induced?
3 hours (6 for aspirin and 12 for chocolate)
what must be placed prior to gastric lavage?
cuffed ET tube
what can be used at the end of gastric lavage?
activated charcoal (leave for 10 minutes)
can charcoal be given if emesis has been induced?
yes - wait 30 minutes so charcoal isn’t vomited
other than emesis, what can be used to enhance the clearance of toxins?
cathartics
enema
diuresis
what do cathartics do?
reduce the time a toxin is exposed to the GI tract
what toxicities can IV lipid emulsion be used for?
local anaesthetics
calcium channel blockers
macrocyclic lactones
pyrethrin
what are antidotes?
any compound which counteracts the effect of a toxicant
what analgesics should be avoided in toxicity cases?
NSAIDs (GI problems)
what analgesics should be used in toxicity cases?
opioids (pethidine)
what can be used to treat seizures?
diazepam
phenobarbital
propofol
what species are lilies toxic to?
cats
what is the first sign of lily toxicity in cats?
gastritis - vomiting
what is the major consequence of lily toxicity?
acute kidney injury (neurological, salivation…)
how is lily toxicity treated?
induce emesis
activated charcoal
fluid therapy
how do pyrethrins affect mammals?
CNS affected by prolonging sodium conductance (increase nerve firing)
what are the clinical signs of pyrethrin toxicity?
salivation
tremor, ataxia, depression
hyper/hypothermia
what can be used to treat pyrethrin toxicity?
bathing
emesis
activated charcoal
diazepam
what does paracetamol toxicity cause?
oxidative injury to RBCs
hepatotoxic (hepatic failure)
what are the clinical signs of paracetamol toxicity?
vomiting abdominal pain tachycardia pallor cyanosis chocolate colour MM
how can paracetamol toxicity be treated?
emesis (within 2 hours of ingestion) activated charcoal cathartics ascorbic acid N-acetylcysteine
where is ethylene glycol metabolised?
liver by alcohol dehydrogenase
what is ethylene glycol metabolised to?
glycolic acid (metabolic acidosis0 oxalic acid (renal epithelial damage)
what are the three clinical phases of ethylene glycol toxicity?
GI irritation
CNS toxicity
nephrotoxicity
what are the clinical signs of the first phase of ethylene glycol toxicity?
ataxia tachycardia PUPD vomiting (2-12 hours post ingestion)
what are the clinical signs of phase 2 of ethylene glycol due to?
metabolic acidosis
what are the clinical signs of the second phase of ethylene glycol toxicity?
anorexia, vomiting
depression, hypothermia
(8-24 hours post ingestion)
what are the clinical signs of phase 3 of ethylene glycol due to?
oliguric renal failure
what are the clinical signs of the third phase of ethylene glycol toxicity?
large/painful kidneys oral ulceration vomiting seizures (1-3 days post ingestion)
what crystals can be found in the urine of animals with ethylene glycol toxicity?
calcium oxalate monohydrate crystals
how is ethylene glycol toxicity treated?
(poor prognosis past phase 1) supportive care (IV fluid) antidote
what are the antidotes available for ethylene glycol toxicity?
ethanol (CNS/respiratory depression)
fomepizole (best)
how do ethanol and fomepizole work as an antidote to ethylene glycol toxicity?
inhibits alcohol dehydrogenase
how do anticoagulant rodenticides work?
vitamin K antagonists
what effect does rodenticides antagonising vitamin K have?
prevents certain clotting factors being activated (coagulopathy)
how is anticoagulant rodenticide toxicity treated?
vitamin K supplementation (absorbed better with fatty foods)
supportive (for blood loss)
what effects does cholecalciferol rodenticides have?
increase calcium absorption (from intestines, osteoclastic from bone, reabsorption in renal tubules)
what are the clinical signs of cholecalciferol toxicity related to?
hypercalcaemia
how is cholecalciferol toxicity treated?
emetic, activated charcoal treat hypercalcaemia (calcitonin, saline diuresis)
what is ingested to cause metaldehyde toxicity?
slug/snail pellets
what type of toxicity does metaldehyde cause?
neurotoxicity (then hepatotoxicity if they survive)
what are the clinical signs of metaldehyde toxicity?
anxiety, restlessness, salivation, tremors, ataxia, seizure, coma
how is metaldehyde treated?
emesis, gastric levage
liquid parafin
fluid therapy
diazepam (seizures)
how do NSAIDs cause toxicity?
inhibit prostaglandin synthesis
what can be done to treat NSAID toxicity?
emesis, gastric lavage
cathartics
repeated doses of charcoal
why are repeated doses of activated charcoal needed for NSAID toxicity?
NSAIDs undergo enterohepatic recirculation
what are methylxanthines found in?
chocolate, tea, coffee (caffeine and theobromine)
what are the clinical signs of methylxanthine toxicity?
ventricular arrhythmias
tremor/seizure
GI upset
how is methylxanthine toxicity treated?
emesis and activated charcoal
keep bladder small (absorbed across the wall)
what is the toxic effect of grapes/raisins in dogs?
acute kidney injury (proximal tubular necrosis)
what are the clinical signs or marijuana toxicity?
hypothermia
depression, disorientation
compulsive eating (munchies)
how is marijuana toxicity treated?
supportive therapy
repeat charcoal administration
what does xylitol cause?
hypoglycaemia (massive insulin release)
how can xylitol toxicity treated?
emesis
N-acetylcysteine
supportive therapy (glucose)
what causes toxicity to onions/leeks?
disulphide and thiosulfate
what does onion/leek toxicity cause?
Heinz bodies and haemolysis
