what are the 2 major classes of anticoagulant rodenticides?
coumarins and indanediones
what is one of the characteristics of these drugs that make it a common toxicosis in small animals?
how do the anticoagulant rodenticides work?
block action of vit K epoxide reductase, vit K is gone
are 1st or 2nd generation rodenticides more potent? by how much?
2nd, by 10-100x
what are the first generations?
what are the second generations?
what kinds of drugs can kill with one dose?
what drugs are coumarins?
what drugs are inandiones?
are cats or dogs more resistant to brodifacoum toxicities? by how much?
cats are 100x more resistant
what should you know about dogs and brodifacoum LD50?
have a large range, should use the lowest number to calculate worst case scenario
what's the extent of protein binding for anticoagulant rodenticides?
what's the half life for anticoagulants?
does relay toxicity occur with anticoagulants?
absorption of anticoagulant rodenticides is ___________
slow but complete
when do you reach the peak plasma level with anticoagulants?
what clotting factors are inhibited with anticoagulants?
2, 7, 9, 10
which coagulation pathways are affected by anticoagulants?
intrinsic, extrinsic, common
without the coagulation factors, you can't get _______ to occur, which prevents _______
carboxylation rxns; Ca binding
what happens if you can't bind Ca like you should?
what does Vit K epoxide reductase do?
reduces vit K to make it active
what does vit K do to coag factors?
attaches carboxyl groups to them to activate
in addition to preventing clotting, what else happens with anticoagulants?
capillaries get damaged
how should you handle patients who ingest anticoagulant rodenticides?
what are the early signs of anticoagulant tox?
what's the primary lesion/problem of concern with anticoagulant toxicity?
how long does it take to see bleeding problems w/anticoagulant toxicity?
what will you see with hemorrhage from anticoagulant toxicity?
petechia, epistaxis, hematemesis, melena, intrapulmonary bleeding, intrathoracic, intra-abdominal, intra-articular, hypovolemia, shock, irregular pulse
with anticoagulant toxicity, what do you see on a coag panel first because it's the most sensitive?
anticoagulant toxicity: what is the PCV?
normal or decreased
anticoagulant toxicity: what are FDP levels?
normal until bleeding
anticoagulant toxicity: what are platelet levels?
normal or a little low
to differentiate anticoagulant toxicity from DIC: what are platelet levels with DIC?
to differentiate anticoagulant toxicity from DIC: what are FDP levels with DIC?
how do you diagnose anticoagulant toxicity?
coag panel, blood panel, chemical analysis of blood/liver, rads, thoracocentesis to confirm hemothorax
anticoagulant toxicity treatment: when do you do a blood transfusion?
PCV less than 15
a plasma transfusion for treating anticoagulant toxicity - what does it do?
replace clotting factors and plasma, but doesn't help w/oxygenation
how do you treat anticoagulant toxicity symptomatically?
blood transfusion, fluids for hypovolemia, oxygen, avoid trauma
how do you specifically treat anticoagulant toxicity?
give vitamin K1 with fatty food
how do you treat anticoagulant toxicity in lactating *****es?
test them for coagulopathy, wean pups asap, give K1 to pups
what's the prognosis of anticoagulant toxicity?
guarded to good (depends on how bad hemorrhage is)
are dogs or cats more sensi to strychnine?
does strychnine have a taste?
what is strychnine's stability in the environment?
stable, stays around for awhile
is strychnine an anticoagulant?
what is the absorption like for strychnine?
what's the distribution for strychnine like?
all throughout body, but more in liver and kidney
what's the half life of strychnine?
what's the significance of the half life of strychnine?
need to treat quickly
where is strychnine metabolized?
how is strychnine excreted?
what is glycine?
inhibitory NT in medulla and SC
what's the mechanism of strychnine?
blocks glycine Rs
what is the result of strychnine poisoning?
CNS is overstimulated, you get extensor rigidity, and respiratory muscles are stimulated so animal suffocates
strychnine binding to glycine Rs: what are the characteristics of this binding?
what's the onset time of signs with strychnine poisoning?
15 min to 2 hrs
what early signs do you see with strychnine poisoning?
sawhorse stance, nervousness, hyperesthesia, muscle stiffness, facial grin, ears erect, blepharospasm (blinking)
what later signs do you see with strychnine poisoning?
tetanic seizures (bilateral, symmetrical), sudden onset of seizures, opisthotonus (extensor rigidity), dilated pupils, respiratory distress, asphyxiation
what kinds of seizures do you see with strychnine poisoning?
tetanic, bilateral, symmetrical, set off by external stimuli
what happens to pupils in OP poisoning?
what happens to pupils in strychnine poisoning?
what are the differentials for strychnine poisoning?
OPs/carbamates, chlorinated hydrocarbons, metaldehyde, Pb, tetanus, etc.
what are the differentials for anticoagulant rodenticide toxicity?
DIC, congenital factor def, vWB disease, canine ehrlichiosis, platelet deficiency
how do you treat strychnine poisoning?
cause vomiting only if early and no clinical signs yet, lavage w/activated charcoal, diuretics (lasix), acidify urine because this is basic
what do you give for supportive therapy in strychnine poisoning?
prevent convulsions, give artificial respiration
what should you not give for strychnine poisoning?
acepromazine, ketamine, morphine
what should you use to control convulsions with strychnine poisoning?
diazepam, pentobarbital, or methocarbamol
what is metaldehyde used for?
slug and snail bait
what regions of the US will we usually see metaldehyde used?
temperate coastal, southern lowland areas
how is metaldehyde absorbed?
easily by GIT
how is metaldehyde metabolized?
aldehyde dehydrogenase metabolizes it from aldehyde to acid (CHO to COOH)
how is metaldehyde excreted?
how does metaldehyde cause problems?
crosses BBB and causes CNS problems
metaldehyde causes ___________ depression
vasomotor and respiratory
what is the mechanism of action of metaldehyde?
decreases serotonin and GABA in brain
what systems are affected with metaldehyde poisoning?
CNS and GI (shake and bake)
what are the early signs of metaldehyde poisoning?
anxious, restless, depression, salivation, vomition, diarrhea, mydriasis, ataxia, incoordination, hyperesthesia
what are the key diagnostic features to metaldehyde poisoning?
tonic clonic convulsions, hyperthermia
in dogs, what will you often see towards the end of metaldehyde poisoning?
appear to recover, but 2-3 days later get liver failure
what do you see on necropsy with metaldehyde poisoning?
congestion of organs, smells like formaldehyde
what are the differentials for metaldehyde poisoning?
EG, strychnine, OCs, urea, Pb
to diagnose metaldehyde poisoning, what do you see with history and signs?
shake and bake
how do you treat metaldehyde poisoning?
detox - emesis (not if they're going to convulse), lavage, activated charcoal, be aggressive
what's the prognosis of metaldehyde poisoning?
guarded to poor
how do you give supportive therapy for metaldehyde poisoning?
sedation, control seizures, artificial respiration, fluids, cold water baths
how do you sedate and control seizures with metaldehyde poisoning?
diazepam, pentobarb, or methocarbamol
how can you get anaphylactic shock with anticoagulant tox?
give K1 IV or IM (not SQ)