Unlike sheep, goats remain susceptible to internal parasites (‘worms’) throughout their lives.
High levels of internal parasites may cause ill-thrift, scouring, weight loss, anaemia and sometimes even death. Young goats, underweight animals or goats suffering other health problems are particularly at risk.
Treating with an anthelmintic or ‘drench’ can remove worms but it is important to get the dosage and type of drench right. Using a single active drench for goats is not recommended as drench resistance is widespread in New Zealand.
Drench doses are weight dependent. Underdosing is likely to be ineffective and may encourage drench resistance. Overdosing can result in poisoning, particularly with levamisole (‘clear’) drenches or mineralised drenches containing selenium.
Estimating the weight of your goat can be difficult and result in dangerous errors. If you do not have access to commercial livestock scales, use a bathroom scale to weigh yourself on your own and then holding the animal to determine its weight.
Careful management can help reduce your reliance on drenches to control internal parasites in your goats.
Use cattle or horses to cross-graze pastures as these do not share the same parasites as goats
Avoid grazing goats with lambs and hoggets. Both goats and young sheep are very susceptible to internal parasites and share the same worms. Grazing these two stock classes together puts increased parasite pressure on both.
Allow goats to graze longer pastures. Goats have different grazing requirements to sheep and perform much better on grass that is 4cm or more in length. Forcing goats to graze very close to the ground increases their parasite larval intake.
Feed supplements such as hay, silage or commercial pellets/meal. This will reduce your goats’ pasture larval exposure and keep them well fed. Remember animals in good condition are better able to tolerate worm burdens and mount an effective immune response.
Avoid overstocking and overgrazing. Too many animals on a property results in short pasture covers and increased pasture larval contamination.
Parasite management involves many factors and there is no recipe that will work in all situations. Talk to your vet to formulate the best parasite management plan for your goats and the rest of your lifestyle block.