21 January 2000

Anger over OP ban

BOTH sheep industry leaders and vets are reacting angrily to the governments recent ban on organophosphate (OP) dips.

It seems industry experts and vets agree the ban will make treating scab more difficult this winter, and may result in welfare and environmental concerns.

Lamb finishers, in particular, are left with few alternative treatments if scab breaks out in their flocks. NSA chief executive John Thorley says injectables may be suitable for breeding stock but are not suitable for animals imminently destined for the food chain.

"The most effective injectable has a withdrawal period of 72 days." Mr Thorley is worried that removal of OPs will constitute a sheep welfare problem as synthetic pyrethroid (SP) dips are not as effective in scab control.

The government ban on OP dips came about because containers are deemed to pose a risk to handlers, but this action is irresponsible, says vet consultant Chris Lewis. "I could understand if OP dips were banned 10 years ago when their risks were unknown.

"Now handlers know of potential hazards and are much more careful. This is a disgraceful decision and could put the welfare of our national flock at risk."

But the ban on OPs forces producers to use either an injectable or a SP dip. "SPs are not as good as OPs in controlling scab; although flumethrin is scab approved, it is environmentally disastrous."

Injectables are an alternative, but he warns that sheep treated for scab with an ivermectin must have two doses, seven days apart and be moved to clean grazing between each dose, which may not be possible on many farms.

In this situation, he recommends using doramectin, which requires only one dose. However, like ivermectins, treated sheep should be moved to clean grazing.

But injectibles are not as efficient as dipping with OPs, says Mr Lewis. "Dipping cleans away mite faeces and stops sheep from itching almost straight away."

OPs also get the vote from sheep vet consultant Chris Trower. "They seem to give a longer period of protection against scab than injectibles. The Sheep Vet Society is against banning OPs on animal welfare grounds."

Besides welfare, Mr Thorley raises the issue of environmental damage caused by SP dips. "It is common knowledge that SPs are far less friendly to the environment."

"At this time of year when groundwater levels are at their highest, it is safer to dispose of OP products than SPs."