New product option for dipping sheep in Ireland

The high-risk season for blowfly strike is likely to ease in the coming weeks, with attention now also starting to turn to sheep scab and lice. Farmers plunge dipping sheep in Ireland have another option at their disposal following the release of Gold Fleece on to the market by Bimeda Animal Health Limited.

The organophosphate-based dip has been unavailable in Ireland since Osmonds exited the market in 2019, with Bimeda releasing an alternative called Ectoflits. Gold Fleece has been available to farmers in Northern Ireland and Britain with slight differences to the product recently released to the Irish market.

For this reason it is entered twice (Irish and UK products) in Table 1, which summarises plunge dipping products.

It also lists pour-ons for the control of blowfly strike, lice, ticks and keds, with some farmers requesting this information in light of the spike in blowfly strike in parts of the country.

Product characteristics

Gold Fleece is a concentrate for dip emulsion. The active ingredient in the product available in Ireland is Dimpylate (Diazinon Stabilised Technical) 60% w/w while the active ingredient in the UK-based product described as Dimpylate (Diazinon) 60.8% w/w is broadly similar, with a marginally higher concentration.

The Health Products Regulatory Authority (HPRA), which regulates veterinary medicines in Ireland, lists its uses as the prevention and treatment of blowfly strike, keds, lice and sheep scab. The Veterinary Medicines Directorate (VMD), which regulates UK veterinary medicines, also lists Gold Fleece as a tick treatment and prevention product.

There are also withdrawal period differences. The Irish-based product has a meat withdrawal of 35 days, compared to 49 days in UK. The VMD lists the blowfly protection period at up to eight weeks. There is no duration listed by HPRA .

Sheep scab

For all concentrate dips, it is vital to follow the recommended product guidelines for the treatment of sheep scab. Sheep must be fully immersed in the water for at least 60 seconds with their head immersed once or twice. The head should never be held down as this increases the risk of animals swallowing or inhaling some of the wash.

The concentration of dip solution is also key. The recommendation for Gold Fleece is a ratio of 1:500 or, for example, 600ml of product to 900 litres (200 gallons) of water. The dispensing kit will dispense 60ml of product and the replenishment rate is based on this.

For dipping baths or tubs, the recommendation for baths with a capacity of less than 2,250 litres (500 gallons) is to add 180ml of dip after every 36 sheep dipped and restore the bath with water to its original volume. For baths with a capacity in excess of 2,250 litres, 480ml of dip should be added after every 96 sheep dipped along with again restoring the water to its original level.

The recommended point for emptying and preparing fresh dip is at a stage of not dipping more than one sheep for each two litres of dip wash initially prepared. For example, if there is 1,000 litres of wash prepared, the solution should be replaced after 500 sheep. All product characteristics point to the wash being replaced at an earlier stage if the wash becomes very dirty during the day’s dipping.

There is a risk to the operator of organophosphate poisoning where such products are not handled correctly. The following precautions should be taken:

For animals, take the following safety precautions:

In terms of the environment, spent sheep dip may be land-spread at a rate of no more than 5,000l/ha (450gal/ac). A dilution of one part dip to three parts or more of water is highlighted as possibly being necessary to achieve this dilution rate.