D-Limonene And Metaldehde

Question 1

What is an essential oil? And where are they found?

Answer 1

Naturally occurring volatile organic compound (VOC)

Found in leaves, seeds, bark, stems, roots, flowers, and other plants for fruit

Question 2

What are the major uses of essential oils?

Answer 2

Food supplement/additive
Cleaning agent
Therapeutic
Pesticides

Question 3

What is the most common exposure route of essential oils to pets?

Answer 3

Oral, dermal, or inhalation

Question 4

What are the clinical signs of overexposure to essential oils?

Answer 4

Unsteady on feet 
Depression 
Low body temp 
Vomiting 
Diarrhea

Question 5

D-limonene is a major constituent in essential from ??

Answer 5

Citrus fruit peel

Question 6

Is D-limonene hydro/lipo-philic ?

Answer 6

Lipophilic

Question 7

What are sources of exposure to D-limonene?

Answer 7

Botanical insecticide
Botanical herbicide
Biodegradable cleaning agents and solvents

Question 8

What is the toxicity of D-limonene?

Answer 8

Generally concidered safe at 1-5%

Cats are more sensitive than dogs

Question 9

T/F: D-limonene is a photosensitizer that readily oxidizes in air and sunlight, especially to sensitive skin, produces mild irritation or dermal sensitization

Answer 9

True

Question 10

T/F: D-limonene is lipid soluble

Answer 10

True

=> readily absorbed through skin and GIT
-equally distributed in body between circulation and adipose tissue

Question 11

What is the MOA of D-Limonene?

Answer 11

Unknown

-in rats, accumulates in proximal tubules cell-> nephrotoxic

Question 12

What are clinical signs associated with D-limonene?

Answer 12

Ataxia, weakness, recumbency, paralysis

CNS depression, hypothermia, and hypotension

Smell like lemons

Mild to severe skin reaction

Question 13

How do you treat D-limonene toxicity?

Answer 13

Decontaminate
Monitor temp
Fluids if needed

Question 14

What is the prognosis of D-limonene toxicosis?

Answer 14

Excellent -sublethal toxicity (resolve in 6-12hrs)

Worse if rare skin rxn

Question 15

What are the types of molluscicides?

Answer 15

Acetylcholinesterase inhibitors (OPs)

Metal salts- iron(III) phosphate, aluminum sulfate, and ferric sodium

Methiocarb

Metaldehyde

Question 16

What is the most common molluscicide?

Answer 16

Metaldehyde

Question 17

What are the properties of metaldehyde ?

Answer 17

Polymer of acetaldehyde

Highly flammable

Hydrophobic-poorly soluble in water

Short soil half-life (10-14days)- low potential for groundwater contamination

Question 18

T/F: most poisoning’s by metaldehyde in cats and dogs are do to careless placement of bait

Answer 18

True

Question 19

What are the exposure route of metaldehyde?

Answer 19

Inhalation (most toxic)

Ingestion of baits (intermediate toxic)

Dermal (least toxic)

Malicious poisoning of non-targeted animals

Question 20

What is the oral LD50 of metaldehyde in dogs? And cats?

Answer 20

100mg/kg -dog

207mg/kg

Question 21

Once ingested, what must occur to metaldehyde to be absorbed?

Answer 21

Acid hydrolysis -> acetaldehyde

Acetaldehyde and metaldehyde are both readily absorbed

Question 22

T/F: metaldehyde crosses the BBB

Answer 22

True

Question 23

Metabolism and excretion of metaldehyde?

Answer 23

aldehyde dehydrogenase converts acetaldehyde to CO2 -> exhaled

Enterohepatic recirculation
Urine

Question 24

What is the MOA of metaldehyde?

Answer 24

Alters neurotransmitter concentrations and enzyme activities

• decreased brain GABA —> neuro stimulation
• increased monoamine oxidase —> decreased brain serotonin and norepi —> reduce threshold of convulsions

Question 25

The increased neuro-muscular activity induced by metaldehyde can lead to what clinical conditions?

Answer 25

Metabolic acidosis (due to the production of acidic metaldehyde metabolites)

Hyperthermia (due to muscle contractions)

Question 26

What are the clinical signs associated with acute metaldehyde? Toxicity

Answer 26

Acute neurological manifestations

Initial onset—>muscle tremor, salivation, anxiety, hyperestheisa, ataxia, tachycardia, and hyperthermia

Progression to acidosis—> vomiting, diarrhea, depression,and hyperpnea opisthotonos and tonic convulsions

Onset within 1-3hrs

Question 27

Continuous seizures due to metaldehyde an lead to what??

Answer 27

CNS depression, and respiratory failure within 4-24hours

Question 28

T/F: dogs and cats that recover from the acute phase of metaldehyde toxicosis may develop liver failure 2-3days after exposure

Answer 28

False

Only dogs, not cats

Question 29

What lesions are associated with metaldehyde toxicity?

Answer 29

Formaldehyde ora acetaldehyde order in stomach (apple cider like odor)

Granules/bait in stomach

Petechia/ecchymosis in GIT mucosa

Congestion, edema, hemorrhage in lung, liver, and kidney

Question 30

How can you diagnose metaldehyde toxicity?

Answer 30

History
Clinical signs
Stomach contents/odor
Lab analysis

Question 31

What is the treatment for metaldehyde toxicity?

Answer 31

No antidote

Decontamination

• emetic
• gastric lavage
• activated charcoal
• enema

Fluid therapy for metabolic acidosis (sodium lactate)

Monitor for hyperthermia

Muscle relaxants -methocarbamol
Anticonvulsant - diazepam/phenobarbital

Horse—> xylazine and acepromazine

Question 32

What is the prognosis for metaldehyde toxicity?

Answer 32

Good if they survive the first 24hrs

Full recovery takes 2-3weeks
Some post recover liver failure