Rodenticides: Bromethalin Dr. Boots Flashcards
What type of use is bromethalin
General Use Pesticide (GUP)
Exposure/source of bromethalin
Properties
Bait ingestion
Relay toxicosis possible but has not been reported
Effective vs warfarin resistant rodents
no bait shyness
Toxicity of bromethalin
Lethal synthesis
Cats more sensitive than dogs
Dogs more susceptible
Guinea Pigs are resistant
Toxicokinetics of bromethalin
highly lipophilic
rapid oral absorbtion
widely distributed (highest in fat/brain)
Lethal systhesis in liver of more toxic metabolite
mainly excreted in bile (enterohepatic recirc), sm amt in urine
MoA of bromethalin
Uncouples oxidative phosphylation
lack of ATP, cant run Na/K ion pumps
brain & sc primary targets - edema & incr ICP
CS of bromethalin toxicity
Acute or delayed
Acute: 2-24 h, less common, usually w/ supralethal doses
CNS excitatory signs, precipatable seizures
Subacute: 2-3 d, more common
Develop within 2-3 days then progress over 1-2 weeks
Hind-limb ataxia, proprioceptive deficits and paresis
Can progress to paralysis, loss of deep pain response, patellar hyperreflexia, ‘upper motor neuron’ bladder
CNS depression ranging from mild to severe
Various other signs reported (vomiting, anorexia, ‘dementia’, positional nystagmus, Schiff-Sherrington posturing, tremors
Focal motor or generalized seizures (later stages) decerebrate posture in terminal stage.
Lesions seen in bromethalin toxicity
Lab dx
cerebral edema
diffuse white matter vacuolization through CNS
antemortem: chem analysis of bait, stomach contents, vomitus
PM: fat, liver, kidney & brain
Dx of bromethalin
Hx, CS, labs
Ddx: Neurotoxins: strychine, metaldehyde etc
other CNS dz; trauma neoplasia, encephalitis
Tx
Px
No specific antidote
Decontamination, supportive/symptomatic care
Mild cases: signs may resolve over several weeks
Severe: grave px
