Copper Flashcards
What animals are most susceptible to copper toxicosis?
Sheep
can be acute or chronic
What animals are resistant to copper toxicosis?
Poultry and swine
*fertilizer from these animals could potentially have a high level of copper
T/F: Acute copper toxicosis is more common than the chronic dz
FALSE
What clinical signs are seen in sheep with acute copper toxicosis?
rapid onset of severe GI signs: vomiting, colic, hemorrhagic dhr, dehydration and shock (due to indirect corrosive action of copper)
What is the treatment for acute copper toxicosis?
Supportive and symptomatic therapy
T/F: There are no GI signs association with chronic copper toxicosis in sheep
TRUE
How are sheep chronically exposed to copper?
Copper accumulation over time from: feed additives, natural copper in soil/plants, soils contaminated by mining, soils fertilized with swine/poultry manure
- molybdenum deficiency: ratio of copper: molybdenum = 6:1
- unavailability of sulfate
Ruminants have a specific metabolic relationship between which three substances? (copper being one of them)
Why is it important?
Copper
molybdenum
inorganic sulfate
*molybdeum and sulfate will bind to copper and then be excreted from the body - when this ratio is out of balance copper will accumulate in the liver
In what species do you usually see high molybdenum?
Cattle
If there is high levels of copper in the liver PM - what was the cause of copper accumulation?
due to imbalances of molybdenum and sulfate/sulfides
Normal levels of copper in feed (10-20ppm) can cause accumulation when molybdenum is less than ___ ppm, or sulfate is unavailable
1-2ppm
How long does copper accumulation take?
2-10 weeks of exposure
What causes a secondary copper toxicosis?
Previous liver damage can cause the hepatocytes to accumulate copper
What will cause a sudden release of copper from the liver into the bloodstream?
STRESS
this causes an acute crisis from a chronic toxicity
hemolytic/hemorrhagic crisis: weakness, anoreaxia, pale mm, icterus, hemoglobinuria, shock, fever, dyspnea
What hepatocellular components does copper bind to?
Lysosomes, mitochondria, nucleus
accumulation causes degeneration and necrosis
What does the release of excess copper into the blood cause?
Oxidation of RBC membranes increasing their fragility resulting in a hemolytic crisis
copper also oxidized hemoglobin to methemoglobin which can not carry oxygen
What lesions can be noted due to chronic copper toxicosis?
Lesions will be related to the acute crisis - hemolytic shock
icterus, hemolysis, methemoglobinemia (brown blood and “port wine urine)
the liver will be enlarged, yellow, and friable
Kidneys - enlarged, hemorrhagic, blueish-dark, friable
Blackberry jam spleen
What values will be elevated in the blood work of a sheep with copper toxicosis?
Elevated serum or whole blood Cu (> 1.5ppm)
Elevated liver and kidney Cu (> 150ppm and 15 ppm)
Elevated liver enzymes (AST, LHD) - can be noted up to 3-6 weeks before an acute crisis
What are some DDX for copper toxicosis?
Hemolytic agents:
sinz, napthalene, DMSO, guaifenesin
Poisonous plants: Onion, gossypol, red maple
snake venoms
infectious dz: lepto, babesiosis, anaplasma, bacillary hemoglobinuria
What is the treatment for copper toxicosis?
Treatment typically is not practical for sheep (cost vs value)
blood transfusion, IVF, Ammonium tetrathiomolybate, D-penicillamine
What are preventative measures that can be taken for copper toxicosis?
Molybdenized copper phosphate sprayed on pastures (4ounces/acre)
Sheep rations should include Cu/Mo at 6:1 ratio
addition of molybdate to sheep rations at 2-4 ppm
supplemental zinc (250ppm) reduces hepatic copper accumulation
What is the prognosis of copper toxicosis in sheep?
Prognosis is poor
prevention should be the primary focus
What is the difference in clinical signs associated with copper accumulation in the liver of dogs when compared to sheep?
Don’t really get the hemorrhagic crisis - dogs will have more clinical signs of hepatitis
What breeds of dogs are more prone to chronic copper toxicosis?
Bedlington terriers (autosomal recessive disorder)
Westies, Skye terriers, doberman
