Skip to content

Parasite Control at Winter Housing

6 December 2022

The unseasonal autumnal weather in October and record high temperatures at the start of November across the country have allowed farmers to delay housing of stock. However, with a recent change in the weather and flooding in some areas, many animals are now coming inside for the winter.

Housing is an ideal time to get on top of parasites to prevent productions losses by treating for a broad spectrum of parasites. Cattle should be housed free of worms, fluke and external parasites such as lice and mange mites. Warmer temperatures late into the autumn mean there could be an increased risk of a mixed burden. Farmers may well be tempted to control parasites with the use of a combination product however; this is not advised as it may speed up resistance if the treatment is not actually required. Consider worm egg and fluke counts (10 animals per group) and treat as required.

Always consult your vet before treatment and consider drawing up a parasite control plan.

Before considering the parasites themselves, it is valuable to consider the performance of stock over the previous grazing season and how it compared to stock performance and or targets focussing on KPI’s that may have been affected by parasites. For example, body condition score in adult cows and growth rates of calves during their first grazing season.

Reviewing the past grazing season is the first step in planning parasite control for the next year’s grazing season.

Key things to consider with parasite control this winter:

  • Check dosing guns are calibrated
  • Read the label and instructions for the product/s you have chosen carefully to ensure you know exactly what the product does
  • Make sure the product is in date and has been stored correctly
  • Weigh animals and pay attention to dose to weight calculation and dose to the heavier weight (if the weights are similar)
  • Check how the product is applied i.e. pour-on or subcutaneous injection

Related FAS Materials

Winter Housing and Lice | Helping farmers in Scotland | Farm Advisory Service (

Related External Materials

Sign up to the FAS newsletter

Receive updates on news, events and publications from Scotland’s Farm Advisory Service