Copper

Question 1

What is the importance of copper and why is there toxicity concern?

Answer 1

an essential element

range of toxicity is small

Question 2

What other elements besides Mo does Cu interact with?

Answer 2

Zn, Fe, Se

Question 3

What are sources of Cu poisoning?

Answer 3

excess supplmentation
improper Cu/Mo ratio in feed
sprays for parasites/fungi
foot dips
plants
algal treatments
mining operations
genetic predisposition

Question 4

Which animals are more susceptible to Cu?

Answer 4

ruminants
sheep, llama and alpacas are 10x more than cattle (alpacas/llamas dont develop hemolytic crisis)

bedlington terriers (autosomal reccesive)

Question 5

What is the unique feature to sheep and Cu levels?

Answer 5

more susceptible to toxicity but more resistant to deficiency than cattle

Question 6

Why are pigs unique with Cu toxicity?

Answer 6

they metabolize completely different

Question 7

What is the absorption/distribution?

Answer 7

well absorbed (depends on interaction with other metals)

Cu binds to albumin and cerulopaslmin, oxidase enzyme or metallothionein in plasma

storage in liver

Question 8

What is the excretion?

Answer 8

in feces
biliary is limited but crucial for homeostasis

biliary excretion is absent in bedlington terriers (result in chronic Cu poisoning)

Question 9

What is the pathogenicity of acute toxicity?

Answer 9

high levels Cu = protein coagulant
= severe gastroenteritis

Primary syndrome

levels slowly rise in liver (blood still normal until final stages)
Cu has oxidative properties so when it builds up = lipid peroxidation.

antioxidants are depleted

hemoglobin is oxidized to methemoglobin = hemolysis

Question 10

what is the pathogenicity of chronic toxicity?

Answer 10

secondary

- from mineral imbalances in the liver

Question 11

what are the two types of chronic Cu poisoning?

Answer 11

phytogenous chronic
- dietary Cu is normal but low Mo = excessive Cu accumulation in liver (no liver damage)

hepatogenous chronic
- ingestion of plants that cause liver damage (scenico)
= bile excertion impaired = Cu poisoning

Question 12

What are the clinical signs of acute poisoning?

Answer 12

death in 24h
mostly GI
- abdominal pain, nausea, vomiting, salivation, shock, feces (green)

liver
- milk jaundice sometimes

Question 13

What are the PM findings of acute poisoning?

Answer 13

gastroenteritis
erosion and ulceration of abumasum
congestion of other organs
possible centrilobular necrosis and enlargement of the liver

methemoglobin not usually present

Question 14

What are the clinical signs of chronic poisoning?

Answer 14

many months for symptoms to develop (high mortality)
hemolysis = no treatment (rapid)

hemolysis
- hemoglobinuria, hemoglobinemia, methemoglobinemia

liver
- jaundice, elevated liver enzymes (24h prior)

GIT

• generally normal
• anorexia maybe before crisis

locomotor
- weakness, trembling

Question 15

what are the PM changes of chronic poisoning?

Answer 15

liver***
- icterus, enlarged and friable, necrosis

kidney

• hemorrhage, friable, degen, tubular necrosis
• gun metal color

spleen

• enlarged
• black currant jam like

methemoglobin
- chocolate brown discoloration of tissues

GIT
- normal

Question 16

what factors can precipitate crisis of chronic poisoning after accumulation has occurred?

Answer 16

declining plane of nutrition (weather change)
shipping (Stress)
lactation (stress)
exercise (stress)
stress

Question 17

what is the Dx of Cu poisoning?

Answer 17

prior to death Cu blood levels are normal
after crisis it rises dramatically

liver sample or Cu,Mo ratio

Question 18

what can Dx acute poisoniing?

Answer 18

acute gastroenteritis
GI contents blue-green
tissue levels normal

Question 19

What can Dx chronic poisoning?

Answer 19

analysis of feed and liver for Cu:Mo (should be 6-10:1
if poisoned > 15:1
elevated liver enzymes, hemoglobinuria are suggestive

Question 20

What is the Tx?

Answer 20

rarely succesful afte hemolysis

ammonium molybdate (oral)
sodium thiosufate (oral)
thiomolybdate
chelators
Add Mo and Zinc to diet