Unit 3 - Hazards at Home Flashcards
What resources are available for home hazard intoxication situations?
Pet poison helpline
Poison control center
ASPCA National Poison Control center
Toxnet.nlm.nih.gov
What are the characteristics of ethylene glycol?
Clear
Sweet taste
Odorless
What are the sources of ethylene glycol toxicity?
Antifreeze
Automobile fluids - brake, hydraulic, transmission
When do ethylene glycol toxicosis cases typically occur?
Fall & winter
What species are susceptible to ethylene glycol toxicosis? Most commonly affected?
All species are susceptible
Dogs and cats most commonly affected
What are the common causes of ethylene glycol poisoning?
Chewed bottles, spills, wrong drench used
Rank the three types of antifreeze from highest ethylene glycol concentration to lowest.
Permanent (95%) > Diluted (50%) > Propylene glycol (0%)
Where is ethylene glycol absorbed? Metabolized? Excreted?
Absorbed in the GI tract
Metabolized in the liver and kidneys (2-4 hours)
Excretion in the urine(24-48 hours)
What is the MOA of ethylene glycol toxicosis?
- Ethylene glycol metabolized by alchohol dehydrogenase
- Glycoaldehyde metabolized by aldehyde dehydrogenase
- Glycolic acid metabolized by lactic dehydrogenase
- Acidosis occurs
- Oxalic acid binds Ca
- CaOxalate crystal deposition
- Renal necrosis & death
How many stages are there of clinical signs associated with ethylene glycol toxicosis?
3 stages
What is the first stage of clinical signs due to ethylene glycol? When does it occur?
Stage 1 (0.5-12hrs)
Drunken animal: vomiting, depression, PU/PD, & ataxia
What clinical signs occur during stage 2 of ethylene glycol toxicosis? When does it happen?
Stage 2 (12-72 hrs):
Severe acidosis - tachypnea, vomiting, depression/comatose, bradycardia, miosis, seizures
What clinical signs occur during stage 3 of ethylene glycol toxicosis? When does it happen?
Stage 3 (72+ hrs):
Renal failure: Oliguria → anuria, oral ulcerations, convulsions, death
T/F: Ethylene glycol toxicity may go unnoticed until later stages.
True - you may see overlaping of stages
What antemortem samples can be taken for diagnosis of ethylene glycol toxicosis? What is done with these samples?
Serum & urine - both for ethylene glycol detection and clinical pathology
What post mortem samples can be taken for diagnosis of ethylene glycol toxicosis? What is done with the samples?
Kidney - ethylene glycol, histopath (diagnostic on its own)
Rumen content - ethylene glycol
Ocular fluid - Glycolic acid
What CBC abnormalities are associated with ethylene glycol toxicity?
Dehydration, ↑ PCV, ↑ Protein, stress leukogram
What serum chemistry abnormalities are associated with ethylene glycol toxicosis?
Acidosis (large anion gap)
Azotemia -↑ BUN, ↑ Creatinine
Mineral concentrations - ↑Phosphorus, ↑Potassium, ↓Calcium
What urinalysis results are consistent with ethylene glycol toxicosis?
pH of <6.5
Calcium oxalate crystalluria
What tool can be used to detect ethylene glycol in serum?
The ethylene glycol test kit - it is qualitative but an analytical lab is required for it to be quantitative
What gross lesions are associated with ethylene glycol toxicosis?
Sweet odor of oral cavity & GI tract
Kidneys - pale, firm/congestion, +/- pale streaks
What microscopic lesions are consistent with ethylene glycol toxicosis?
Renal tubular necrosis
Oxalate crystal deposition
How is ethylene glycol toxicosis treated?
Decontamination and IV fluids - AC w/in 2 hours of consumption
Prevent metabolism of EG - 7% ethanol IV or 20% ethanol IV
Antidote
What is the antidote for ethylene glycol toxicosis? How does it work?
4-Methylpyrazole - it, along with the use of ethanol, competitively inhibits alcohol dehydrogenase by binding to it
What side effects are associated with using ethanol for the treatment of ethylene glycol toxicosis? Pros to using it?
Side effects - respiratory depressant and CNS depressane (can cause ethanol poisoning)
Cheap
What are the pros and cons of using 4-MP for the treatment of ethylene glycol toxicosis?
Safer but more expensive
What are the caveats to using either ethanol or 4-MP for the treatment of ethylene glycol toxicosis?
They must be given ASAP - once ethylene glycol has been metabolized there is no effect
They MUST NOT be given together
What are the methylxanthines that are of concern with toxicosis in animals?
Caffeine, Theobromine, theophylline
What are the sources of caffeine for toxicosis?
OTC stimulants, coffee beans, regular coffee, decaf coffee, soft drinks, chocolate
What are the sources of theobromine toxicosis?
Cacao beans, unsweetened baking chocolate, cocoa powder, chocolate (dark > milk > white), cacao bean mulch
What are the sources of theophylline toxicosis?
Tea, human asthma medication, various foods and beverages
What is the toxic dose of theobromine in dogs and cats?
Dog - 250-500 mg/kg
Cats - 200 mg/kg
What are the toxic doses of caffeine in dogs and cats?
Dog - 110-200 mg/kg
Cat - 80-150 mg/kg
Why do chocolate compounds pose an increased risk of methylxanthine toxicosis?
Because they contain both caffeine and theobromine
Where are the methylxanthines absorbed? Distributed? Excreted?
I assume GI tract…..Rapid absorption (theophylline has decreased absorption with food)
Wide distribution - can cross the placenta
Excretion - urine, bile, milk
What are the MOAs of methylxanthines (there are multiple)?
- Competetive antagonist of adenosine → bronchodilation, tachycardia, vasoconstriction, CNS stimulation
- ↑ Intracellular calcium
- Inhibition of phosphodiesterase → ↑ cAMP → ↑ Release of catecholamines
- Stimulation of sympathetic nervous system
What clinical signs are associated with methylxanthine toxicosis?
CNS: Hyperactivity, Agitation, Seizures
Cardiac: Tachycardia (200- 300 bpm), Arrhythmias
Elevated motor activity: Hyperexcitability, Tremors, Polyuria
GI irritation: Vomiting, Diarrhea
What lesions are associated with methylxanthine toxicosis?
No specific lesions, but you should evaluate the oral cavity for the presence or odor of chocolate
How is methylxanthine toxicosis diagnosed?
Detection of methylxanthine alkaloid - serum, plasma, urine, GI content, milk
How is methylxanthine toxicosis treated?
ABCs:
Artificial respiration
Control seizures - Diazepam
Control arrhythmias - lidocaine (dogs), propranolol (cats)
↓ BP - Metoprolol, propranolol
Decontamination - emesis, gastric lavage, activated charcoal
