Animal Health: Should I try copper oxide wire particles to control parasites
in my lambs and sheep?
Quite frankly, no! Recently there has been some press announcements
regarding the use of copper oxide wire particles (COWP) (sometimes
called 'needles') to control Haemonchus contortus (Barber pole worm)
infestations in lambs and sheep rather than more familiar dewormers,
such as Ivomec® (ivermectin injectable). COWP is touted as an
alternative to use if resistance of worms to standard dewormers is
occurring. However, sheep producers in Ontario should beware!
Here's what you need to know:
- The product is not registered for use in Canada. You will
not have assurances that any unapproved product you purchase is
efficacious and safe to use in sheep in Canada.
- Copper toxicity can be a problem in lambs and sheep in
Ontario . The label claim for Copinox is for prevention of copper
deficiency. Copper deficiency is not a problem in Ontario.
- Research on parasite control with COWP has not been conducted
in Ontario. Research has been reported on hairy sheep (southeastern
USA), Merino sheep (Australia) and sheep in New Zealand. The results
are not directly applicable to Ontario breeds of sheep. Living and
management conditions are also very different for sheep in Ontario
compared to sheep in southern USA, Australia and New Zealand.
- COWP is not 100% effective. COWP reduces (but does not
eliminate) fecal egg counts and worm counts for the Barber pole
worm in the abomasum (stomach). There is no reduction in the small
intestine. In addition, the reduction in counts does not occur in
all lambs (at least in those given 2 grams of COWP or less).
- COWP is not effective against other worms.
- Safety of COWP has not been adequately evaluated. Higher
doses (4 or 6 grams) given to 4 to 6 week old lambs did increase
liver copper levels above the normal range during the study although
clinical signs of copper toxicity were not seen. Label information
for Copinox recommends that COWP should not be given to pre-weaned
lambs, lambs less than 10 kg in weight, housed sheep or breeds susceptible
to copper toxicity.
- Health, growth, feed efficiency and economic outcomes have
not been adequately evaluated. One study on hairy sheep suggests
that COWP given to pregnant hairy ewes one month prior to lambing
twins results in smaller lambs at birth and at slaughter. The label
claim for Copinox recommends dosing at tupping or during first pregnancy.
Dosing in the second or third month of gestation is only recommended
if copper deficiency is severe.
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