By District Vet Dr Jill Kelly
While goats and sheep share the same internal parasites, such as Barbers Pole Worm and Black Scour Worm, they need to be considered differently in some respects when it comes to managing their worm burdens.
Unlike sheep, goats evolved over many years to deal with worms by using grazing behaviour to stay away from worms – this is why they’re happy browsing from trees, eating from the tops of large grass tufts and sampling the washing from the clothesline. As a result of this evolutionary change, goats developed large and highly efficient livers to deal with the toxins in the trees and other browse plants.
These important differences in goats mean that if you fence them in and ask them to eat within 10cm of ground level (where most of the worm larvae live) they are incredibly susceptible to picking up worms; and that many of the drenches that are used in sheep cannot just be used in goats at sheep dose rates as their liver metabolises them very differently.
Another thing that is really important is to accurately estimate what your goats weigh so that goats can be accurately dosed with drenches and other medications. A set of scales are a good investment, or if you’ve got a smaller flock, girth bands for goats can be helpful to assess body weight.
It is illegal for a producer to use a sheep drench in goats without a prescription from their private veterinarian. There has been some really great research done lately that outlines which sheep and cattle drenches are effective in goats, what an appropriate dose rate is, and what a suitable withholding period and export slaughter interval is, and your private vet is well placed to advise you on this information.
Australia is the largest exporter of goat meat in the world, so it is critical that we maintain this market access by keeping goat meat free of residues. For example, the 2016/2017 National Residue Survey found goat fat samples with levels above the Maximum Residue Limit for moxidectin, even though there is no moxidectin product registered for use in goats. If you develop a good working relationship with your private veterinarian who has a thorough understanding of your goat business they can work with you to ensure that residues do not occur and your goat worm burdens are well managed.