Drenches for goats: using cattle and horse anthelmintics

Equine worming products and cattle pour-on products may be convenient, but these products should NOT be used in goats.

Equine products

These products are attractive to hobby goat owners, because they are sold in individual syringes. However, while the active may be similar to some sheep drenches, the formulation is different. These products are designed for horses and, with pastes in particular, dose rates will be difficult to measure for goats. No research has been done to determine if they work in Australian goats or if they lead to drench resistance.

A case in New Zealand demonstrated that incorrect cross-species use of an anthelmintic achieved poor results. Injectable moxidectin for sheep was given orally to a horse and was only 72% effective, whereas follow-up with an ivermectin (which is accepted as a less potent macrocyclic lactone than moxidectin) product registered for horses was 100% effective.

Cattle pour-on products

Cattle pour-on products should not be used for worm control in goats. Pour-ons should never be used as a drench, as the liquid in which the active ingredient is dissolved is very toxic to the lining of the gut.

Goats have much less subcutaneous fat than sheep and cattle and this can affect the absorption of pour-on products, which must be applied along the back and then absorbed.

Research in 5-month old kids treated with double the dose of eprinomectin pour-on found that although worm egg counts were reduced, when total barber’s worm and worm larvae counts were determined 50 days later, there was no difference in numbers between the treated and control groups. In another experiment with goats and a mixed species infection, the efficacy of ivermectin pour-on was significantly less when compared to the oral and injectable formulations.

In most states, it is illegal to use anthelmintics not registered for use in goats. Even in Victoria, where legislation allows for “over the counter” products for the “major food-producing species”, cattle, to be used in “minor food-producing species”, goats, it is hard to justify using these “over the counter” horse or cattle products, when sheep and goat products with the same actives are available.

Even more important than the safety and efficacy of using unregistered drenches is the risk that illegal drench use will jeopardise Australia’s valuable export markets for goats if unacceptably high chemical residues are found in exported goat products.

Veterinarians must consider the circumstances of use and prescribe an appropriate withholding period that will keep chemical residues at slaughter under acceptable limits, to protect Australia’s valuable goat export markets.

If using any non-approved product instead of an anthelmintic registered for goats, a DrenchCheck-Day10 is essential to check effectiveness.

What should you do instead?

All goat owners should have a veterinarian with whom they have an ongoing relationship i.e. the vet has visited your farm and knows your management. This is essential as eventually you will have an emergency goat health problem and will need a vet’s advice in a hurry.

Your vet can then prescribe anthelmintics “off-label” and, if needed, can repackage and sell you small amounts of drench to treat your goats.

What about animal welfare?

All goat owners have animal welfare obligations and it is not acceptable to allow goats to suffer from high worm burdens.

Goat owners have an obligation to seek veterinary attention and treatment if their goats have serious health issues. Treating clinically ill goats with a treatment that is not registered for use in goats, and which is known not to work, does not mean that you have met your animal health obligations.