Fe. Vanniekerk et al., AN ASSESSMENT OF THE TOXICITY OF PARENTERAL TREATMENT WITH COPPER EDTA AND COPPER HEPTONATE IN SHEEP, Journal of the South African Veterinary Medical Association, 65(2), 1994, pp. 46-51
The toxicity of 2 parenteral copper (Cu) supplements was investigated.
Di-sodium copper ethylene diamino tetra acetate (Cu EDTA) and Cu hept
onate were administered to sheep (n = 9) by a single subcutaneous inje
ction at a concentration of 0,2, 1 and 2 mg Cu/kg each (Trial 1.) Nine
sheep were untreated and served as controls. The same treatments were
applied to 2 sheep each (Trial 2) with the addition of 3 mg Cu/kg liv
e body mass as Cu heptonate, and Cu heptonate administered intravenous
ly at rates of 0,2, 0,4 and 0,6 mg Cu/kg live body mass. In Trial 1, 6
7 % of the sheep treated with Cu EDTA at 2 mg Cu/kg live body mass die
d within 3 to 17 d after treatment, while no mortalities occurred in s
heep where Cu heptonate was administered at the same dosage rate and e
ven at 3 mg Cu/kg live body mass (P less-than-or-equal-to 0,01). Post-
mortem examination suggested acute Cu toxicity in all cases. Liver Cu
concentrations were markedly increased (P less-than-or-equal-to 0,05)
by both supplements in groups of 3 treated sheep slaughtered over a 3-
month period compared to control animals. The liver Cu concentrations
of sheep that succumbed to Cu toxicity were within the normal range of
100 to 450 mg/kg DM. Results from Trial 2 suggested that the 2 sheep
treated with 2 mg Cu/kg live body mass as Cu EDTA, experienced a haemo
lytic crisis between 5 and 11 d after treatment, resulting in the deat
h of one of these sheep. The haemolytic crisis was characterised by a
severe decrease in haemoglobin concentration and haematocrit. Sheep tr
eated with Cu heptonate did not show any indications of similar compli
cations, even when given 3 mg Cu/kg live body mass subcutaneously or 0
,6 mg Cu/kg live body mass intravenously.