Farmers have some important decisions to make with regard to winter dosing. These decisions include what parasites to cover when dosing and, of course, which products to use.

Suckler farmers have an easier decision to make because they have a far wider range of products available to them. Basically, apart from making a choice on the parasites covered, their only concerns are meat withdrawal periods. They have the luxury of being able to use oral products, pour-ons and injectables.

Dosing for dairy farmers is a much different scenario. The extra key considerations that they have to deal with are the fact that so many fluke doses cannot be used in milk-producing animals and, also, they must factor in milk withdrawal periods.

Only two drugs can be used for fluke dosing in dairy cattle. These are oxyclosanide, which is the active ingredient in products such as Zanil, Levafas Diamond, Rumenil, etc, and triclabendazole, which is the active drug in Fasinex and its generics such as Endofluke, Triclaben, etc. In all these products, the milk withdrawal period is sufficiently short that even a cow with a very short dry period is unlikely to be affected. Albendazole, which is in Valbazen, Albex and Endospec, etc is a wormer with some activity against fluke and this can also be used.

The big disadvantage with these dairy permitted flukicides is that they are oral products. With the ever-decreasing availability of labour on farms, oral dosing a herd is not a chore to look forward to. Some farmers try to get around this by adding the product to ration and feeding it in the milking parlour or by adding it to the feed via the mixer wagon. While these methods save labour, one is never certain that each cow has consumed the requisite dose.

When it comes to pour-on wormers, dairymen have to be very careful also. Ivomec pour-ons generally have a milk withdrawal period of 60 days, so it is imperative that the cow has a dry period of over 60 days. This is especially relevant in years where milk price is good and farmers are tempted to carry on milking for longer than they normally would.

So, all farmers have to factor in quite a lot of different considerations when deciding on the dosing regimen that suits them and their situation best.

Donal Murphy works at Sliabh Luachra Veterinary Centre, Rathmore, Co Kerry. Sliabh Luachra Veterinary Centre is part of XLVets. XLVets is a group of progressive practices who are working together to achieve a better future for agriculture and veterinary in Ireland. For further information, go to www.xlvets.ie.