TOX EXAM 2 204|2025 QUESTIONS AND CORRECT WELL DETAILED ANSWERS (VERIFIED ANSWERS ) GRADED A+++

TOX EXAM 2 204|2025 QUESTIONS
AND CORRECT WELL DETAILED
ANSWERS (VERIFIED ANSWERS )
GRADED A+++

What species is resistant to lead poisoning? - correct answers pigs


Sources of lead - correct answers Paint chips/dust, fishing tackle (sinkers),
lead based toys, lead shot/bullets, lead batteries, motor oil, old pesticides, old
building foundations


Seasonality of lead poisonings in cattle - correct answers spring/summer


Are young or old animals more susceptible to lead? - correct answers young
more susceptible


toxicokinetics of lead ingestion - correct answers ingestion -> (poorly)
absorbed in GI tract -> enters bloodstream -> enters bone, milk, brain, and feces


***need periodic testing of survivors due to bone deposition and
remodeling/release***


Lead is better absorbed in GI tract at what general pH? - correct answers
more acidic = increased absorption


4 MOAs of lead poisoning - correct answers ***MULTIPLE MOAS***

,1. Binds sulfhydryl groups
• ↓ Heme synthesis
• Altered GABA transmission


2. Competes with Ca2+ & other divalent ions
• Displaces Ca2+ from binding sites -> altered nerve & muscle transmission


3. Inhibition of membrane enzymes
• Calmodulin -> ↓ smooth muscle contraction
• Na+/K+ pumps


4. Interferes with mineral absorption
• Ca2+ and calbindin


Lead onset of clinical signs - correct answers ~48h


3 categories of lead clinical signs - correct answers Neuro


Neuro and GI


GI


Most common clinical signs after DOGS ingest lead - correct answers
***Gastrointestinal signs predominate***
• Vomiting
• Anorexia
• Diarrhea - GI sloughing & bleeding
• Tender abdomen

,Most common clinical signs after CATTLE ingest lead - correct answers
***Neurologic (CNS) predominant***
• Blindness
• ↑ vocalization
• Ataxia
• Head pressing
• Tremoring & Convulsions
• Bruxism
• Circling
• Aimless wandering


***lead should always be a differential for neurologic cattle***


Most common clinical signs after CATS ingest lead - correct answers Non-
specific
• Lethargy
• Anorexia
• Vomiting
• Weight loss


Most common clinical signs after BIRDS ingest lead - correct answers
***Neurologic***
• Depressed / weak
• Ataxic
• Weight loss
• Esophageal paralysis -> regurgitation
• Wing droop

, Most common clinical signs after HORSES ingest lead - correct answers
Neurologic
• Paralysis of recurrent laryngeal nerve -> ***roaring***
• Ataxia


Lead antemortem samples - correct answers • Whole blood
• Milk


Lead postmortem samples - correct answers Lead testing on:
• Liver
• Kidney
• Bone
• GI Ct


Histopath on:
• Brain (not for direct lead test)


Lead poisoning findings on dog blood smear - correct answers Nucleated
RBCs


Basophilic Stippling


***NO anemia***


Lead poisoning gross lesions - correct answers Few gross lesions
• Brain - Fluorescence of laminar cortical region
• Avian - Emaciated with muscle wasting