Rodenticide Flashcards
Is strychnine a weak acid or a weak base?
Weak base
Which rodenticide is an alkaloid form strychnos nux vomica seeds?
Strychnine
Which rodenticide is a white powder with a bitter taste that is moderately water soluble?
Strychnine
How long can strychnine persist in the environment?
Up to 40 days
Which animals are susceptible to strychnine toxicity?
All animals are susceptible.
T/F: Cats are most frequently poisoned by strychnine and more sensitive than dogs.
False - Dogs most frequently poisoned by strychnine and more sensitive than cats.
What is a toxic dose of strychnine for dogs?
0.5-1.2 mg/kg
What is a toxic dose of strychnine for horses, cattle and pigs?
0.5 mg/kg
What is a toxic dose of strychnine for cats?
2 mg/kg
What is a toxic dose of strychnine for poultry?
5 mg/kg
Where is strychnine rapidly absorbed from?
GI tract
What will decrease the toxicity of strychnine?
Vomiting
Food in the stomach may do what to the strychnine toxicity?
Increase or decrease toxicity
Does strychnine accumulate in a particular area?
No
Is strychnine highly protein bound?
No
Can strychnine cross the BBB?
Yes
Where is strychnine metabolized?
Excreted and in what form?
- Liver
- Urine as both metabolites and unchanged toxin
Does strychnine undergo enterohepatic recirculation?
Yes
Most of a strychnine dose is eliminated in what amount of time?
About 24 hours
Which rodenticide blocks the post-synaptic effect of glycine in spinal cord?
Strychnine
What is an important inhibitory neurotransmitter to motor neurons and interneurons in the spinal cord, brainstem and thalamus?
Glycine
What are 4 clinical signs that strychnine poisoning can lead to?
- Highly exaggerated reflex arcs
- Muscle spasm
- severe extensor rigidity
- Tonic seizures
How fast is the onset of strychnine toxicity?
Rapid onset: 10 mins-2 hours
What are 3 early signs of strychnine toxicity?
- Apprehension
- Panting
- Nausea/vomiting
Mydriasis, stiffness, muscle twitching and hyperthermia are clinical signs of what rodenticide toxicity?
Strychnine
What do the clinical signs of strychnine poisoning progress to?
Tonic seizures and opisthotonos
What is opisthotonos?
Tetanic spasm in which spine and extremities are bent with convexity forward, the body resting on head and heels.
What is a clinical sign exhibited by dogs with strychnine poisoning?
Sardonic grin
Death from strychnine poisoning is due to what?
Respiratory failure
Are there lesions seen with strychnine poisoning?
Generally few or none
What are 4 antemortem specimens preferred for chemical detection of strychnine poisoning?
- Stomach contents
- Bait
- Serum
- Urine
What 3 things are used to diagnose strychnine poisoning?
- History
- Clinical signs
- Lab confirmation
What are the 2 main forms of treatment for strychnine poisoning?
- Decontamination
- Supportive/symptomatic care
What are 2 forms of decontamination that can be used for strychnine poisoning?
- Emesis if not contraindicated
- Activated charcoal
Patients with strychnine poisoning may require what?
Sedation for 24-72 hours
What are 4 categories of drugs that should be avoided with strychnine poisoning?
- Opioids
- Phenothiazines
- Neuromuscular blockers
- Dissociated anesthetics
What is the prognosis for strychnine poisoning?
Reasonably good
