Flashcards
Toxicology
Cards in this deck (109)
- 1ToxicologyThe dose marks the poison!!
The poison causes a harmful effect in the animal
The route affects toxicity
Toxicity of poison can be extreme to harmless
Species respond differently
Decontaminate!
Treat the patient not the poison - 2What is a poison?Substance that causes death, illness or injury that can result in death or chronic illness
- 3ToxicityProducts tested before put on the market for safety
- 4LD50Lethal dose that will kill 50% of animals
-Some animals can die at a dose lower than the LD50
Not many antidotes available - 5RatbaitAnticoagulant bait
LD50 is 0.5mg/kg in cats - 6Exposure and time for animal to reactAcute - within 24 hours
Subacute - days
Chronic - months - 7Routes of exposureIf something is eaten eg. selenium it is less toxic than when injected
Topical, injectables and vapours of some substances/inhalation of gas - 8Animal variationSpecies - cats! (no enzyme)
Breed
Sex
Age: physiology of young animals not as developed as adults, can't eliminate toxins as fast. Old animals have less function in liver and kidneys so more susceptible - 9Assessing the animalWhat is the animal's current condition
History: what was it exposed to
Clinical signs
Advise the client and refer to the vet
In clinic: clinical exam, give supportive care and decontaminate - 10Things to do in clinicSave vomit, faeces and urine
Record and label it with careful handling
Don't assume poisoning
Call national poison centre for information on the product, not advice - 11Questions to ask when taking historyHow long has animal had clinical signs?
Clinical signs? Mentation, behaviour, recumbent, respiration
What did you feed it?
Do you have a compost bin?
Do you know what it has access to?
Snug and snail bait in garden?
How much was ingested? How much does the animal weigh? - 12Principles of toxicologyLimit exposure
Limit absorption
Stabilise the animal: oxygen, fluids, warmth
Promote elimination: laxatives, fluids
Identify the poison: stabilise and decontaminate first, then give antidote - 13Limit exposurePrevent access to poisons
eg. keeping cows off lush pasture and avoid nitrate toxicity - 14DecontaminationEmetics: dogs, cats and pigs (everything else can't vomit)
Activated charcoal + laxative
Laxatives:
-magnesium sulphate (epsom salts)
-Paraffin oil (NOT concurrently with activated charcoal: will bind charcoal and prevent it absorbing the toxin) - 15Treat the patient not the poisonYou may never find out what the animal was exposed to
Decontamination and hydration
Control bleeding and convulsions
Oxygen - 16Identifying toxinsAsk the client what the animal could have been exposed to
Have they used anything in their property recently? Slug bat, rat poison etc - 17AntidotesUse if available
Eg. vitamin K for rat bait - 18Decontamination of dermal exposure-Wash off with copious amounts of tepid water, not hot (vasodilation increased absorption) or cold (hypothermia)
-Baby shampoo or mild dish soap can be used if needed
-If contaminant is oil or tar based, use vegetable oil to aid removal - 19Decontamination for oral exposureIf less than 4 hours, give an emetic UNLESS substance is corrosive
How do you know if something is corrosive? Examine the mouth mucus membranes for erosion, hyper-salivation, licking and pain
If >4 hours limit GI absorption, use activated charcoal and laxatives if appropriate.
If corrosive: use milk or water - 20EmeticsApomorphine in dogs
Xylazine - ok in cats
Washing soda crystal on tongue at home
Hydrogen peroxide 3%
Emetics not useful with cannibis toxicity - 21Emetic contraindicationsSpecies: Don't use in anything except cats, dogs or pigs
Don't induce vomiting for corrosive toxins
Petroleum product ingestion - aspiration risk
Any CNS depression or convulsions: have reduced reflexes and can aspirate - 22Gastric lavageWithin 1-2 hours of ingestion
Anaesthesia, intubation to prevent aspiration
Right lateral recumbency with head down
Warm water and saline flush down oesophagus
Give activated charcoal - 23Activated charcoal contraindicationsNot effective at binding acids or alkalies
Alcohol or ethanol
Petroleum
Some metals: iron and mercury - 24Common poisonsAnticoagulant rodenticides
-first gen: warfarin
-Indanediones: leave tissue residue
2nd gen: Brodifacoum - 25Rat bait mechanism of actionCompetes with Vitamin K epoxide reductase, preventing recycling of vitamin K to make clotting factors
Results in haemorrhage
-Prolonged OSPT - 26Anticoagulant clinical signs3-5 day delay
Dyspnoea
Lethargy and weakness
Coughing
Pale mucus membranes from bleeding
Anorexia
Vomiting
Melena
Haematuria
Lameness - 27Symptomatic and supportive care for anticoagulant toxicityVitamin K1 - give slowly over fluids
Warmth
Oxygen
Fluids
Clotting factors or blood transfusion:
PCV <20%, dyspnoea, anaemia - 28Advice to ownersFind out what product and how much eaten
Decontaminate the animal in clinic
Use an emetic if <4 hours from ingestion
* clinical signs take 3-5 days to appear*
Animals may die suddenly from internal haemorrhage
2nd gen, products can cause problems for 30+ days, require Vit. K for a month
Vitamin K1 is the best treatment, K3 not as good for vet use - 29OrganophosphatesCommon agricultural product
- 30CarbamatesInsecticides and snail bait
- 31Organophosphate mechanism of actionInhibition of acetylcholinesterase at cholinergic receptors
Affects autonomic nervous system function:
Often fatal, quickly but can be delayed causing weakness - 32Muscarinic clinical signs of organophosphate toxicitySalivation, lacrimation, urination, defecation ,dyspnoea and emesis
Will resolve with atropine - 33Nicotinic clinical signs of organophosphate toxicityMuscle tremors
Not affected by atropine - 34CNS clinical signs from organophosphate toxicityAnxiety
Hyperactivity
Seizures - 35Diagnosis of OP toxicityAcetylcholinesterase activity will be decreased, take a blood sample or brain tissue in post mortem
Give a test dose of 0.02mg/kg atropine: if animal responds with dry mucus membranes it indicates that it is not OP toxicity
Some animals have a garlic odour - 36OP and carbamate treatmentAtropine sulphate is an antidote for both
2-PAM for OP toxicity only
Symptomatic treatment: fluids, oxygen, warmth/cool as needed. Monitor TPR - 37OP and carbamate advice to clientsClinical signs come on quickly (~15 mins)
Decontaminate the animal in clinic ASAP
Explain the symptoms and importance of giving antidote rapidly to owner, prognosis is much better if treatment is given within 12 hours
Don't use tranquilizers (acepromazine) - 38What questions should you ask the owner for rat bait poison?Do you know how much he ate?
How much did you put out?
How much does the dog weigh?
Condition of the dog: breathing, mentation, recumbency - 3915kg dog eats 200g of Talon (0.05g/kg) Did he eat a toxic dose?0.2kg eaten x 0.05g = 10mg
10mg/15kg = 0.67mg - 40Treatment for rat bait if eaten 1 hour agoInduce emesis
-Sodium carbonate if at home
Depending on how much eaten, follow up with activated charcoal - 41CholecalciferolNot an anticoagulant
Very long half life as it is in the bile which is recycled
Results in imbalance in calcium homeostasis causing mineralisation of body tissues - 42Clinical signs of cholecalciferol toxicityLethargy, weakness, vomiting, ataxia
melena and haemetemesis
Twitching, seizures and depression
Renal and liver failure in late stages
Can take 24 hours or more for onset of signs - 43Biochemistry in cholecalciferol toxicityHypercalcaemia
Hyperphosphataemia - 44Treatment of cholecalciferol toxicityActivated charcoal, repeated doses
Fluids to maintain kidney function
Frusemide
Prednisone/prednisolone
Pamidronate disodium: treats hypercalcaemia
or Salmon calcitonin, not together - 45Advice to client for cholecalciferolGive emetic and activated charcoal ASAP
4 hours post ingestion and clinical signs present, without treatment the animal will die in 2-5 days from renal failure.
Once the animal has kidney disease, the prognosis is poor
Requires several weeks of nursing care - 46Sources of lead poisoningPainted surfaces
Soil and grass contamination
car batteries
Roofing caps
Petrol products and old oil
Shotgun pellets - 47Susceptibility to lead poisoningAll ages and species are susceptible, but
toxicity is increased in young animals
Dogs and cattle most likely to get poisoning
50-900mg/kg is an acute dose - 48Clinical signs of lead poisoningHysterical barking
Chomping
Paralysis
Blindness
Abdominal pain - 49Treatment for lead poisiningLarge animals: magnesium sulphate for decontamination. Binds lead and it is passed out. Also has laxative effects
Small animals: activated charcoal + laxative
Diazepam to control convulsions - 50Chelation therapy for lead poisoningCalcium EDTA
Binds lead - 51Advice to clientsLead poisoning is a public health issue - owners should see their GP
Remove the lead fragments from the animal before giving chelation therapy
Emetics and charcoal have limited use
Notify the government if livestock have been poisoned - 52Sources of nitrate toxicityPasture plants, crops and weeds
weather and fertiliser: rain and overcast weather causes excessive nitrates in plants
Hungry cattle gorge themselves on lush pasture and get toxicity
Contaminated water
Fertilisers
High nitrite (preservative) in dog roll - 53Mechanism of nitrate toxicityConversion of nitrate to nitrite is toxic
Nitrite oxidises haemoglobin to methaemoglobin, causes oxygen starvation and death - 54Clinical signs of nitrate toxicityRespiratory distress
chocolate blood and brown MM
Salivation and abdominal pain
Ataxia, tremors and convulsions
sudden death - 55Diagnosis of nitrate toxicityDiphenylamine test on plants
Nitrate test strips
Test aqueous humour from dead animals
Send plant sample to lab - 56Treatment of nitrate toxicityTriage
Treat standing animals before recumbent ones
Don't stress them out
Move mildly affected animals off pasture
Provide safe feed
Give methylene blue - has long WHP - 57PhenolsDisinfectants and clay pigeon fragments
Corrosive lesions in the mouth and GI tract
Denatures and ppts proteins can cause necrotic lesions on skin
Corneal lesions on eyes - 58Advice to clients for phenol toxicityMilk or eggs, not water. Given orally
Don't use phenol disinfectants in kennels or catteries - 591080 mechanism of actionsodium fluoroacetate
Builds up citrate by interfering with the Krebb's cycle causing acidosis - 60Clinical signs of 1080 toxicityvocalisation
Running / excitement
Tenatic seizures
Frequent urination and defecation
Metabolic acidosis
Hyperthermia
Hyperglycaemia and decreased ionised blood calcium - 61Treatment for 1080 toxicityDiazepam for seizures
Sodium bicarbonate fluids for acidosis or
Acetamide fluid (NOT both)
Support care - requires anaesthesia to prevent seizures and excitement - 62Advice to clients for 1080 consumptionShort period before onset of clinical signs
Give emetic if no signs yet
Bring in to clinic ASAP!!
Must see the vet immediately if showing clinical signs. Don't make them vomit if giving signs, can aspirate
Prognosis is poor!
Animal requires anaesthesia so can do gastric lavage
Acetamide is a promising antidote - 63Metaldehyde clinical signsslug/snail bait
Early signs: Anxiety, grimacing, restlessness
Blindness
Metabolic acidosis
Excitation to narcosis
Tachycardia and tachypnoea
Nystagmus in cats
"Shake and bake" - 64Treatment of metaldehyde toxicityMetabolic acidosis due to muscle activity
-Reduce muscle activity
Symptomatic and supportive care
Use anticonvulsants if needed:
Diazepam, barbituates and methocarbamol - 65Advice to clients for metaldehyde poisoningSerious! bring in ASAP
Clinical signs onset soon after ingestion
Can cause liver and renal disease
Memory loss, diarrhoea and blindness
NO antidote
requires decontamination and nursing care - 66Pyrethrin and pyrethroid sourcesInsecticides
- 67Clinical signs of pyrethrin toxicityCats are very sensitive to pyrethrin
Ear twitching, - 68Treatment of pyrethrinsNo antidote!
Decontaminate
Rinse off ASAP if topical
Oral charcoal and laxatives
Nursing care
Monitor temperature
Anti-convulsives: methocarbamol best
as it prevents muscle twitching - 69Advice to clients for pyrethrin toxicityInsecticides are mostly safe, EXCEPT in cats
Thoroughly decontaminate and wash off animal
Symtpmatic care
control tremors with diazepam or methocarbamol
NEVER use dog products on cats - 70ParacetamolDepletes glutathione in the liver (needed for detoxification)
Causes oxidative injury:
Liver damage in dogs
RBC damage in cats - 71Clinical signs of paracetamol poisoning in dogsTachypnoea
Tachycardia
Abdominal pain
Vomiting
Anorexia
Methaemoglobinaemia
Facial and paw oedema - 72Paracetamol toxicity in dogsSevere liver damage
24-36 hours post ingestion - 73Paracetamol clinical signs in catsCyanosis
vomiting
Dyspnoea
Oedema in face and paws - 74Paracetamol toxicity in catsMethaemoglobinaemia
Heinz body anaemia
Recumbency, hypothermia and shock
depression - 75Treatment of paracetamol toxicitySymptomatic and support care
warmth and oxygen
Parvolex as a glutathione substrate
Methylene blue and ascorbic acid for methaemoglobinaemia - 76Advice to clients regarding paracetamolDON'T GIVE IT TO YOUR PETS
- 77Macrocyclic lactones: Ivermectins and abamectinEnterohepatic circulation
Excreted in faeces - don't let dogs eat poop
Long half lives
Decontaminate with activated charcoal
Insecticides and paste wormers for horses - 78Ivermectin and Abamectin toxicity in mammalsEffects GABA in CNS and decreases neuron excitability
Mutations cause a defect in the BBB so some dogs much more sensitive to low doses (eg. Collies and Collie crosses)
Normal dogs are sensitive to high doses - 79Clinical signs of Ivermectin and Abamectin toxicityAtaxia, stiff gait, high stepping, depression, reversible blindness
- 80Avermectin treatmentSupportive care
Repeated doses of activated charcoal - 81Avermectin advice to clientsPrevent access to these products (pastes, drenches and pour ons)
Decontaminate ASAP to prevent a long recovery period - 82Lilium sp. toxicitySerious acute renal disease in cats if they eat the plant or pollen and drink the vase water. Die without treatment
In the first few hours: salivation, depression and vomiting - 83Lilium toxicityDecontaminate early! emesis and charcoal + laxative. Fluids!! Support renal function
Poor prognosis for anuric cats, can do peritoneal dialysis - 84Arum lilyProduces burning sensation in the mouth and renal damage due to precipitation of oxalate
- 85Arum lily toxicity clinical signsHypocalcaemia: staggering, weakness and tremors
- 86Treatment of Arum LilyNo emetics in ruminants!
Decontaminate with activated charcoal and laxative - 87Bracken fernDepression and weakness from anaemia
Nervousness and lethargy in horses
Poor prognosis with the development of anaemia, requires transfusion and treatment - 88ButtercupRanunculum poison
Causes mouth pain resulting in salivation, gastric ulceration, colic and diarrhoea
Weakness, staggering and death if eaten lots
Supply alternative feed
Symptomatic treatment and decontamination - 89Foxglovecontains digitalis and digoxin
abdominal discomfort, vomiting and anorexia in small amounts
Strong, bounding pulse and slow heart rate, tremors and death with large amounts - 90Foxglove decontamination in large animalsActivated charcoal expensive
Use a purgative or magnesium sulphate then treat symptoms - 91Goat's rueRespiratory distress due to lung damage
Diuretics and NSAIDs to reduce pulmonary oedema - 92HelmockHas purple blotches on the stem. Stems are hollow
trouble swallowing, diarrhoea, muscle weakness, tremors, coma and death
Rapidly toxic, treat ASAP.
Activated charcoal and laxative
Sub-lethal doses can be detected in milk - 93KarakaDevelop paralysis due impaired ATP synthesis and cytotoxicity.
Require good nursing care and decontamination. Remove seeds - 94MacrocarpaCauses third trimester abortion and retained placenta
- 95Ngaioleaves have serrated edges and hate small, white flowers
Causes photosensitivity. Can be confused for facial eczema, but facial eczema is in late spring - summer. Poisoning can occur at any time of year. - 96RagwortCause liver damage and impaired function resulting in giant hepatocytes. Sheep are more resistant than cattle and horses
- 97RhododendronGI clinical signs: vomit and regurgitation. Decontaminate! charcoal and laxative
Depression, muscle weakness, tremors, convulsions and death from respiratory distress
Dried leaves still poisonous - 98Ryegrass mycotoxin diseasesStaggers - Lolitrem B
Facial eczema - sporidesmin (pithomyces chartarum) - 99NightshadeGI upset in mild cases
Restrict access
Don't feed potatoes to stock - 100TutuCNS excitation compound
Takes 24-48 hours for clinical signs
Seizures, tachypnoea, tachycardia, muscle twitches and tremors
Good nursing care and barbituates to reduce clinical signs - 101YewFluids
- 102Questions to ask ownersWhen did clinical signs start?
Did you see them ingest anything and if so, when? How much?
Anything around your household that they could have ingested?
How much do they weigh? - 103Principles of treatmentStabilise the animal:
Fluids at shock rates, oxygen, warmth diazepam if seizing, propofol and atropine
Activated charcoal and sorbitol (sorbitol to prevent gut stasis and constipation) - 104AtropineTreatment for organophosphate toxicity (slug & snail bait)
Organophosphates block acetylcholinesterase at cholinergic receptors
Acetylcholinesterate will regenerate in some poisons as it doesn't tightly bind, but will overwhelm and age enzymes causing neuropathy and death - 105Emetic useNOT for corrosive toxins: check mouth for irritation
NOT for animals with clinical signs, seizures or unconsciousness due to aspiration risk
Not in patients that ingested toxin >4 hours - 106Difference between first and second generation rat poisoningFirst gen requires several doses causing bait shyness. Warfarin and Pindone
Second gen: Long acting, 30 days ish
Brodifacoum (Talon) - 107Rodenticide mechanism of actionCompetes with Vitamin K epoxide reductase
Treatment: Must give vitamin K1 - 108SLUDDEOrganophosphate toxicity muscarinic signs
S
L
U
D
D
E - 109Organophosphate toxicity: Intermediate syndromeDelayed onset anorexia
Depression
Generalised weakness
Muscle tremors
Ventroflexion of the neck
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- Pharmacology and Toxicology Flashcards on Toxicology, created by Kelly Scott on 13/07/2020.
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