TOXICOLOGY
EXAM 1 (PHARM
AND TOX EXAM 2)
Everything is toxic in the right _______. - Answers -Dose
Hydrogen peroxide dose - Answers -1 mL/lb
Signalment - Answers -species, breed, age, sex, weight, reproductive status
When evaluating toxicology start with _____________ and then the first things to do
are______________. - Answers --Hx, clinical signs, diagnostic data, post mortem
observations
-look carefully, touch, smell carefully in well ventilated area, taste: NO DON'T DO IT,
think of liquids or items that can be dissolved in liquids and always place specimens in
the freezer
What is considered a poison (toxin, toxicant)? - Answers -any substance that can cause
an adverse effect when introduced into a living biological system
Toxicity - Answers -amount of substance when introduced into the body that will cause
an adverse effect under specific set of conditions (if circumstances change, toxicity can
change)- related to dose
Risk - Answers -the likelihood or probability that a substance will induce a disease
under the conditions of use/ do the math! Risk assessment!
***Potential toxins present different risks to different animals in different
circumstances***
D - Answers -Degenerative, Developmental, Dementia
A - Answers -Anatomic, Anomalies, Allergic, Autoimmune
,M - Answers -Metabolic, Mechanical
N - Answers -Neoplastic, Nutritional
I - Answers -Inflammatory, Infectious, Immune-mediated Idiopathic, Ischemic
T - Answers -Toxic, Trauma, Tumor
Toxicant - Answers -composition, chemical properties, formulation and vehicle (e.g
arsenic- inorganic vs organic and acute vs chronic)
Host animal - Answers -biotransformation (absorption-distribution-metabolism-
excretion), morphologic features (e.g. nitrate-ruminant/monogastric), species (e.g. lily-
cats; grapes-dogs), breeds (e.g. MDR1)- KNOW SIGNALMENT!!!
External or Environmental - Answers -temperature (e.g. ergot)
Topical exposure to dry substance - Answers -brush/vacuum/shave; follow with a bath
(2-3 times) and rinse with room T water; make sure to dry the animal to prevent
hypothermia!
Ocular exposures - Answers -· Indications: irritants, corrosives from dermal exposures
(skin to eye)
o flush up to 15-20 minutes (commercial eye wash, tap water)- sedation often required
or topical anesthetic
o Monitor: pawing, rubbing at eyes, redness, lacrimation, blinking, squinting...
-Medical or surgical interventions
Inhalation exposures - Answers -· Indications: irritants, corrosives, gas, smoke
inhalation, CO
o Remove from environment
§ Patent airway/adequate ventilation
§ Endotracheal tube/O2/Anti-inflammatories
§ Examples: anhydrous ammonia/phospine gas/house fires
§ BIRDS!!!
Which anti-emetics (and/or pro-kinetics) are potentially detrimental to give to MDR1
mutants? - Answers -maropitant, ondansetron
In what species, what agents, and what situations are emetics contraindicated? -
Answers --rodents, rabbits, horses, ruminants
-corrosive agents, hydrocarbons- volatile, toxicant/drug has anti-emetic properties
-symptomatic or soon to be, already vomited or GIT empty, brachycephalic breeds,
medical conditions: megaesophagus, lar par, risk of aspiration pneumonia, recent
surgery
, Oral exposures option 1 - Answers -· Option #1- Dilution
o Corrosive agents (acids/bases); pH <3 or >11, and concentration// cleaning agents,
dish washer + laundry detergents, potpourri, essential oils
o Milk (large volumes can cause V/D)/water/*raw egg whites
o Flush- rostral direction-toad licking
o Follow-up: GI protectants (omeprazole for 2 weeks, sucralfate)
Oral exposures option 2 - Answers -· Option #2- Emetics
o Goal- remove material from stomach
§ Different substances absorbed at different rates and in different parts of GIT
§ NOT ALL comes up and some never vomit
§ Choice, route of emetic, may delay administering activated charcoal (45 min or longer)
· Give emetic, once emesis has occurred (or not occurred), then give an anti-emetic or
pro-kinetic (metoclopramide, maropitant, odansetron, dolasetron) and then give AC
· KEY- in a timely fashion
· Human poison control centers like AC/gastric lavage better
APCC 'trick'
Apomorphine hydrochloride - Answers -§ Dogs- ** dopamine receptors of the
chemoreceptor trigger zone of the area postrema of the medulla
§ Not as effective in cats b/c they have more alpha 2 adrenergic
§ Effective (>90%) IV, not SQ, OK IM, conjunctival sac
§ Mix fresh: 1-15 minutes/duration: 30-45 minutes/ usually post IV= immediate and short
duration
§ Second dose generally not recommended (after 30 min-2 hr may see tolerance)-
apomorphine hydrochloride will bind to Mu receptors in medulla and cause anti-emetic
effect
§ Side effects: *prolonged vomiting, persistent signs of nausea (lip licking, salivation)-
control with metoclopramide, maropitant, etc.; reddened eyes (conjunctival sac)
§ RARE: Serious side effects (CNS/respiratory depression) may be reversed with
naloxone- not sure how this works (competitive agonist?)
Ropinirole ophthalmic solution in clinic - Answers -§ Good alternative to apomorphine in
dogs
§ Dogs-**dopaminergic receptors of the chemoreceptor trigger zone of the area
postrema of the medulla which sends information to the vomiting center
§ EFFECTIVE (95% within 30 minutes)/ convenient single use dropper/ very specific
instructions
§ Administer according to label instructions
§ *Second dose can be administered 20 minutes after administration of the first dose
§ Side effects: prolonged vomiting, persistent signs of nausea (salivation), reddened
eyes, transient lethargy, tachycardia- control with metoclopramide (D2 receptor
antagonist, anti-emetic)- very serious (up to 2-4 hours, use caution in cardiac patients)
§ Questionable for use in dogs <4.5 months of age, <4 lbs, pregnant/lactating