Toxicology - Exam 2 Material Flashcards
Regarding copper toxicity, what are the hisotlogical lesions that youre gonna see?
- Tubular nephrosis, acute , multifocal, severe with hemoglobin casts
Gastroenteritis
**Hepatocellular necoris, acute, ** multifocal severe
Regarding copper toxicity,
- what are some different sources for food animals?
- Which animals are affected?
1) dietary imbalance
2) A) Sheep (this spp is most sensitive) and note that the exposure is CHRONIC B) THIS IS AN AUTOSOMAL RECESSIVE DISEASE IN DOGS –> COPPER STORAGE DISEASE
3)
What is the mechanism of action for copper toxicity?
- oral –> chronic exposure but abrupt onset
- Excess copper stored in the liver; note that Cu-Mo-S are excreted in the bile; and lysosomes (function to ???)
- Liver has high storage capacity/reach capacity + stress
Cu released –> hepatocellular necrosis –> serum Cu –> hemolysis (most the time)
Discuss the clinical pathology for copper toxxicity
- Liver enzymes –> elevated GGT and AST
- Anemia due to hemolysis
- Hemoglobinemia/uria, hyperbilrubinemia/uria
- Methemoglobinemia (brown blood)
Regarding copper toxicity, discuss treatment/prevention
Prognosis: guarded - poor for lcinically affected animals (both small animals and large animals)
Treatment + prevention: enhance copper excretion (FA):
- **Mo-S source: enhances feceal, urinary, biliary excretion/slows down absorpption and enhancs excretion
- Chelators –> Decrease body burden
Discuss copper storage disease (chronic active hepatitis) for canines and treatment for it
Chronic accumulation!
- Not excessive in diet
- Autosomal reccessive –> seen in Bedlington terrier breed and sometimes in West Highland white terriers
Chronic bouts of intermittent hepatti
Treatment –> Penicillamine (chelator that reduces body burden and zinc acetate (reduces absorption long term); treatment is usually long tterm
Regarding cyanobacteria, discuss the basics of it
- Targets the liver and CNS
- Criteria about charcteristics where these algal blooms are found –> 1) ubiqitoud 2) stagnant-slow moving 3) decreased oxygen, 4) increased nutrients (phosphates, nitrates and sulfates), 5) quiet weather 6) warmish water - Temperature and pH (?????) 7)high light intensity
Discuss the mechanims of action for cyanobacteria
All species suscpetible
Microcystin/nodularin/cylindrospermopsin - specific to the liver
- Massive necrosis with hemoorhage
- Cylindrospermopsin - renal necrosis
- cylindrospermopsin also affects the kidneys
Shock –> DIC –> Death
Discuss clinical isgns associated with cyanobacteria
Clinical signs are liver specific
- elevated ALT, bile acids, bulirubinemia/uria and prolonged PT-PTT
- low albumin, low protein, low BUn, cholesterol
- Potential renal changes
Discuss the basics of anticoagulant rodenticide toxicity
- All species are sueceptible except for cats, carts are pretty resistant to it.
What is the mechanims of action for Anticoagulant rodenticide toxicity
- Vitamin K is an essential cofactor in actiavtion of clotting factors II, VII, IX, X. When rhis occurs, ‘active’ vitam,in K –> inactive vitamin K epoxide
- **Vitamin K epoxide reductase
- Rodenticdes inhibit enzyme –> prevents recycling ‘active’ vitammin K**
- Loss of clotting factors, therefore we are likely going to see prolonged clotting times
Regarding anticoagulant rodenticide toxicity, what are the clinical signs?
- Onset: 2-3-5 days; clotting prolongation occurs erlier but after 36-48 hours, we start seeing a delay when 65-80% of factors are lost)
Treatment is dependent upon: hemorrhage site, speed, and volume. HEMORRHAGE CAN OCCUR ANYWHERE
- 70% BLEEDING INTO THE LUNG, THORAX, AND MEDIASTINUM
Discuss diagnosis criteria for anticoagulant rodenticide toxicity
- History of use/exposure: Assume long acting
- Clinical pathology, clinical signs: site, volume, speed of hemorrhage
DO NOT RULE OUT IF OATIENT IS NOT ANEMIC … prolonagtion of clotting times occurs before anemia is seen
Reememebr, it is important to differentiate between 1) loss vs 2) hemolysis vs 3) lack of production
DO NOT LIST MALABSORPTION AS AN ANSWER ON THE EXAM
For clotting pannel, expect prolonged PT and PTT
Discuss the treatmnent for antiocoagulant rodenticide toxicity
1) do the math!!!! if the dose is NOT TOXIC, send the animal home
2) Toxic dose: establish baseline clotting panel
**A) Decontaminate **
B) Plasma/blood transfusions if needed
C) Vitamin K1
Think about decontamination several hours post ingestion, then most likely you are gonna wanna administer Vitamin K1. If you have a patient that vomits after you administered activated charcoal, then you MUST ADMINISTER THE FIRST DOSE SUB-Q. Treat for 4 weeks too. After 4 weeks therapy, you must wait 36 - 48 hours before checking the clotting times to see if they’re still clapped or not.
Regarding NSAIDs, what is a prostaglandin?
A prostaglanding is a lipid derived chemical messemnger mostly acting in a paracrine fashion which means they act on the site where they are released