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Flashcards in Copper Deck (32)
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1

What are the 2 types of copper toxicosis?

Acute copper toxicosis

Chronic copper toxicosis (in sheep)

2

T/F: Acute copper toxicosis is not common

TRUE

3

What is the source of acute copper toxicosis?

Ingestion of high concentrations of copper (Cu sulfate in insecticides)

4

Clinical signs of acute copper toxicosis?

Rapid onset of severe GI signs including vomiting, colic, hemorrhagic diarrhea, dehydration and shock, due to the direct corrosive action of copper

5

What is the treatment for acute coper toxicosis?

Supportive and symptomatic therapy

6

What are the sources of chronic copper toxicosis in sheep?

  • Excess copper
    • Feed additives
    • Natural copper in soil and plants (mostly clovers)
    • Soils contaminated by mining
    • Soils fertilized w/ poultry litter or swine manure
  • Molybdenum deficiency
  • Unavailability of sulfate

7

What is the normal copper:molybdenum ratio?

6:1

8

What is the normal relationship between molybdenum and copper?

Molybdate (MoO42-) binds to copper in tissues at a ratio of 4:3, to form copper molybdate (CuMoO4) that is readily excreted in urine

9

What is the normal relationship between copper and sulfate in the body?

Rumen sulfates and sulfites are reduced to sulfides that bind to copper, reducing its absorption

10

What causes accumulation of copper in the liver?

Imbalances between copper, molybdenum, and sulfate

11

What are the normal feed and forage copper levels? When do these levels cause Cu accumulation?

Normal levels = 10-20 ppm

Cause accumulation when molybdenum is deficient (<1-2 ppm), or sulfate is unavailable

12

Accumulation requires about ______ exposure in sheep.

2-10 weeks

13

What might liver damage and stress cause?

  • Liver damage might cause copper accumulation by hepatocytes (secondary copper toxicosis)
  • Stress may cause sudden loss of copper from the liver to the blood

14

Where is copper absorbed from? What removes it?

Copper is absorbed from the intestine then carried by serum and erythrocytes to different tissues

The liver removes most of copper from the blood

15

What is copper bound to?

Hepatic lysosomes, mitochondria, and nucleus

16

How is copper mainly excreted?

Bile

17

What does copper accumulation in the liver cause?

Liver degeneration and necrosis

18

What will cause a hemolytic crisis?

Release of copper from the liver and excess copper in blood causes oxidation of erythrocyte membranes increasing their fragility--> hemolytic crisis

19

T/F: Copper also oxidizes hemoglobin to methemoglobin (cannot carry oxygen)

TRUE

20

What are the clinical signs of chronic copper toxicosis in sheep?

Sudden onset of weakness, anorexia, pale mm, icterus, hemoglobinuria, fever, dyspnea, and shock

21

Lesions of chronic copper toxicosis in sheep?

  • Icterus, hemolysis, and methemoglobinemia
  • Liver is enlarged, yellow, and friable
  • Kidneys are enlarged, hemorrhagic, bluish-dark, and firable (gunmetal kidneys)
  • Spleen is enlarged and dark brown to black (blackberry jam spleen)

22

What is found on chemical analysis following chronic Cu toxicosis in sheep?

  • Elevated serum or whole blood Cu (> 1.5ppm)
  • Elevated liver and kidney Cu (< 150ppm, and 15ppm respectively)

23

Are liver enzymes elevated following chronic Cu toxicosis in sheep?

Yes (AST, LDH), 3-6 weeks before a hemolytic crisis

24

Diagnosis for chronic Cu toxicosis in sheep?

History, sudden onset of hemoglobinuria, jaundice, and signs of shock and resp insufficiency, lesions of hemolysis, and lab diagnosis

25

DDx (chronic Cu toxicosis in sheep)?

  • Hemolytic agents
    • Zinc, naphthalene, phenolics, DMSO, guaifenesin
  • Poisonous plants
    • Onion, gossypol (cottonseed), rad maple (Acer rubrum), mustard
  • Certain snake venoms
  • Infectious diseases
    • Lepto, babesiosis, anaplasmosis, bacillary hemoglobinuria

26

Treatment of chronic Cu toxicosis (sheep)?

  • Ammonium tetrathiomolybate (1.7-3.4 mg/day IV or SC for 3 treatments on alternate days)
  • D-penicillamine (50mg/kg orally for up to 6 days)

27

Prevention of chronic Cu toxicosis in sheep?

  • Molybdenized Cu phosphate sprayed on pastures at the rate of 4 ounces/acre
  • Sheep rations should contain Cu:Mo at 6:1 ratio
  • Addition of molybdate to sheep rations at 2-4ppm for prevention

28

T/F: Ammonium molybdate (50mg) and thiosulfate (0.3-1.0 g) orally per day prevents toxicosis in individual sheep

TRUE

29

T/F: Supplemental zinc (250ppm) reduces hepatic molybdenum accumulation

FALSE--it reduces hepatic copper accumulation

30

Chronic copper toxicosis in dogs?

  • Mainly seen in Bellington terriers due to an autosomal recessive disorder at 2-6 years of age
  • Other breeds including West highland white terriers, Skye terriers, and Doberman pinschers are also susceptible

31

T/F: Excess free copper causes chronic active hepatitis and liver necrosis due to lipid peroxidation of mitochondrial membranes

TRUE

32

T/F: Hemolytic crisis due to sudden release of copper is much more likely in dogs

FALSE--much less likely in dogs