Bromethalin Rodenticide Flashcards
Is bromethalin a general use or restricted use pesticide?
general use
What species is more sensitive to Bromethalin poisoning?
Cats are more sensitive than dogs
Dogs are more susceptible as they are more likely to ingest it
What species are resistant to Bromethalin poisoning?
Guinea pigs
they lack the correct metabolic enzymes for lethal synthesis
Is bromethalin lipophilic or water soluble?
Lipophilic - readily absorbed orally
Where is Bromethalin distributed in the highest amount in the body?
Fat and brain
What is the metabolism of Bromethalin ?
metabolized by N-demethylation in the liver to a MORE TOXIC metabolite: Desmethylbromethalin
***lethal synthesis
What is the half life of Bromethalin and how is it excreted?
Half life in the rat = 5-6 days
mainly excreted in the bile, small amount in the urine
*likely undergoes enterohepatic recirculation
What is the MOA of Bromethalin ?
Uncoupleing of oxidative phosphorylation
= lack of adequate ATE and insufficient energy for Na/K ion pumps
What are the primary targets or tissues affected by Bromethalin toxicosis?
Brain and Spinal cord
- these rely heavily on oxidative phosphorylation
- further tissue damage may occur through lipid peroxidation
T/F: Signs for Bromethalin toxicosis are always acute
FALSE
acute or delayed
*acute is less common
What clinical signs are associated with acute Bromethalin toxicosis?
occurs 2-36hrs post ingestion
“convulsant syndrome” - generally a higher dose
CNS excitatory signs - severe muscle tremors, hyperthermia, running fits and hyper excitability - that may be precipitated by light or noise
(may note CNS depression in end stage)
What is the prognosis of Bromethalin Convulsive syndrome?
POOR
difficult to treat
What are the clinical signs associated with subacute Bromethalin toxicosis?
onset 1-4 days - MORE COMMON - Paralytic syndrome
Develops within the first few days and progresses over 1-2 weeks
hind limb ataxia, proprioceptive deficits, paresis, can progress to paralysis and loss of deep pain
CNS depression
Other: vomiting, anorexia, nystagmus – may progress to sz late stage
Death may occur due to respiratory failure
What lesions are associated with Bromethalin toxicosis?
Cerebral edema (intramyelinic edema) Diffuse white matter vacuolization in the white matter
Paralytic syndrome is usually associated with what kind of Bromethalin dose?
Lower dose
Convulsive syndrome = high doses
What are the most important factors for diagnosing Bromethalin toxicosis?
History and clinical signs
theres nothing very striking in blood work besides a mild hyperglycemia
Chemical analysis is expensive and takes a long time
What is essential to prevent further CNS damage due to Bromethalin ?
Decontamination!!
Emetic is only successful if it is done within 1-2hours post ingestion since it is quickly absorbed
- Activated charcoal with sorbitol - needs to be repeated
- want to avoid cathartics with magnesium
What is sorbitol?
A cathartic - will act as an osmotic agent to pull fluid into the colon
Should do one dose of toxiban with sorbitol and repeat doses without sorbitol to prevent hypernatremia
What is the treatment for Bromethalin toxicosis?
lipid emulsion therapy should be considered
Supportive and symptomatic when signs are present - mannitol, furosemide, anticonvulsants, Gingko biloba
What is the prognosis of Bromethalin toxicosis?
Mild cases - signs may resolve over several weeks
Severe cases = grave
