Animals – Parasite control for healthier animals

Effective worm control is essential for maintaining the health and productivity of livestock, whether you own one or 1000 sheep. Parasites, including gastrointestinal worms, lungworms and liver fluke, can cause significant health issues if not properly managed. Poor growth or weight loss are milder consequences of parasites, but a severe burden can lead to significant scours, blood loss and death.

Here are some key elements of an effective worm control programme:

Rotational grazing: Regularly rotating pastures helps disrupt the lifecycle of worms by preventing the build-up of infective larvae. Grazing less intensely, so livestock don’t graze too low to the ground, is important because most larvae reside in the lowest few centimetres of grass.

Mixed-age grazing: Grazing young, susceptible animals with older, more resistant ones can reduce the overall worm load. Older animals typically have better immunity and lower worm egg excretion rates.

Cross-species grazing: Using cattle, sheep and horses to graze pastures alternately can help reduce the worm burden, as these animals are not hosts for the same parasites. The non-host animal will ‘vacuum up’ the worm larvae without being adversely affected by them.

Nutrition: Well-nourished animals are better equipped to handle parasitic infections. Ensuring a diet with adequate vitamins and minerals supports the immune system and enhances the overall health of the livestock. In some situations, a quality lick block can be enough, while others require supplemental feeding. Continuously grazed pasture alone rarely provides a complete diet for an animal.

Shelter and hygiene: Ensure that stables and other shelters are well-ventilated and kept clean to prevent the build-up of moisture and manure, which can harbour parasites. Prevent stock access to ponds or watercourses and eliminate boggy areas in the paddock.

Drenching: With increasing emphasis on reducing drench use, it’s important to note that effective worm control can be achieved with less reliance on chemical treatments. This approach, however, requires better monitoring and strategic drenching.

Faecal egg count (FEC) monitoring: Regular FEC monitoring helps determine the worm burden and the efficacy of the current drenching programme. Collecting faecal samples and having them analysed by a veterinarian can show how many worm eggs are being shed in the manure, helping to decide if and when to drench.

Young stock: Young animals are particularly vulnerable to worms, due to their undeveloped immunity. Dual-active drenches, which combine two different anthelmintic compounds, are recommended to ensure a broad spectrum of action against various worm species.

Adult livestock: For adult animals, especially those in good condition, the use of strategic drenching based on FEC is advised. This targeted approach minimises the risk of developing resistance by avoiding unnecessary treatments.

Breeding stock: For pregnant and lactating females, maintaining a balance between effective worm control and minimal drug residues is crucial. Strategic drenching before critical periods, such as lambing or calving, can help manage worm loads effectively.