Iron, Copper, and Molybdenum Toxicosis Flashcards
What are the usual sources of iron toxiciosis?
Accidental ingestion of human oral supplements
Overdosage in pet or piglets
What are the three forms that iron is present in?
Which is the most irritating and astringent?
Elemental
Divalent (ferrous)
Trivalent (ferric) —> most irritating and astringent
T/F: toxicity of oral iron preparations is more toxic than parenteral preparations
False
Parenteral is more toxic than oral
Greater than 5000ppm iron in diet can lead to ________ in piglets because it interferes with phosphate absorption
Rickets
How is iron absorbed ??
Ferrous iron absorbed in small intestine using energy-dependent carrier
Ferrous iron is oxidized to ferric iron once absorbed
Ferric iron binds to ___________ in plasma and is distributed throughout the body
Transferrin
70% to hemoglobin
10% to myoglobin
Rest to enzymes or stored in liver/spleen/bones
What is the MOA of iron toxicosis ?
Primary on GI tract: GI tract, liver, and CV leading to shock and death
GI: direct corrosion of the GI mucosa, vomiting, diarrhea, and shock
Liver: accumulation causing mitochondrial damage, acidosis and shock
CV: free radical lipid peroxidation and damage to membranes, increased vascular permeability, hemorrhage, vasodilation, CV collapse, and shock
Injectable iron can cause what type of reaction causing an acute rapid death?
Anaphylactic reaction -histamine release
What are the 4 stages of acute iron toxicosis?
- Nausea, vomiting, diarrhea, GI hemorrhage
- Apparent recovery
- Vomiting, diarrhea, GI hemorrhage, metabolic acidosis, coagulation disorders, hepatic failure, CV collapse
- GI obstruction
What lesion is associated with parenteral preparations of iron?
Yellowish-brown discoloration at injection site and near lymph node
What lesions are seen with oral preparations of iron?
GI ulcer and hemorrhagic enteritis
Congestion of liver, kidney, liver necrosis, icterus, and hemoglobinuria
How do you treat iron toxicosis?
GI decontamination:
- emesis, or gastric lavage before onset of clinical signs
- activated charcoal is NOT effective
- milk of magnesia to precipitate iron
Supportive therapy
- IV fluids, dehydration, acidosis, and hypovolemic shock
- GI protectants like sucralfate
Chelation therapy
-only indicated in severe toxicosis with deferoxamine
What is more common, acute or chronic copper toxicosis?
Chronic
Vomiting, colic, hemorrhagic diarrhea, dehydration, and shock are signs of acute/chronic copper toxiciosis?
Acute
—> direct corrosive action of copper on GI
What are the sources of chronic copper toxiciosis?
Excess copper
- feed additives
- natural in soil/plants
- contaminated by mining
- fertilized with poultry litter/swine manure
Molybdenum deficiency
-normal ratio is 6:1 copper/molybdenum
Unavailability of sulfate