Drenches for goats: alternatives to registered commercial drench products

Many hobby goat breeders or commercial goat producers wanting to target organic markets are interested in alternatives to registered commercial anthelmintic (drench) products. The registration refers to those registered for goats through the Australian Pesticides and Veterinary Medicines Authority (APVMA), or registered for use in sheep or cattle, but that can be used in goats with a veterinary prescription.

Some organic certification programs do not allow the use of anthelmintics or vaccinations (such as Barbervax®). The Australian Certified Organic (ACO) Standards do not allow the use of either, but schemes differ in their requirements and some may allow them where the need is demonstrated.

What else can be used instead of registered anthelmintics?

Pasture management, rotational grazing, improved nutrition, genetic selection and feedlotting (zero-grazing) are all tools that are available for goat producers who wish to manage their goats by organic principles. More information can be found in the Your Program section of WormBoss and in the NSW DPI Primefact: Managing internal parasites in organic livestock production systems.

The internet abounds with suggested alternatives to registered anthelmintics, however, most of these have not been tested, and when they have been, they have been found not to work. None of these products, including apple cider vinegar, garlic and various other natural remedies, are recommended. More information about the issues associated with alternative worming treatments can be found on the website of the American Consortium of Small Ruminant Parasite Control (www.wormx.info).

Feeding a product and then observing an effect, e.g. a reduction in worm egg count, does not necessarily mean that this product was the cause of the effect. A control group of animals kept under the same conditions is needed, as are repeated trials.

If using any non-approved substances instead of a registered anthelmintic, a DrenchCheck (a worm egg count before and 14 days after the product is used) is the minimum essential check for effectiveness.

What about copper?

Some regions of Australia are deficient in copper, and goats can respond if this nutritional deficiency is corrected. However, copper can accumulate in the liver and adding copper sulphate to the diet or drenching with copper sulphate is one step closer to copper toxicity. Once the threshold in the liver is reached, all the copper stored is released into the blood at the same time. This causes the red blood cells to rupture, resulting in red urine, very dark kidneys, pale mucous membranes, fast breathing, weakness and sometimes death. Sometimes animals are just found dead. Goats are slightly more resistant to copper poisoning than sheep.

With copper toxicity, unlike overdosing with other minerals, there is a sudden toxicity and generally sudden death. Until then, the goats look and produce normally and there are no warning signs that liver levels of copper are building up.

There can also be increased risk of copper toxicity in areas with plants containing pyrrolizidine alkaloid, such as Echium (Paterson’s Curse) and Heliotropium (Blue heliotrope) spp. Where animals are shedded with no access to dirt, there may also an increased risk of copper toxicity.

Figure 1. Dark abdominal contents from ruptured blood cells in copper poisoning. Source: Dr Sandra Baxendell.
Figure 1. Dark abdominal contents from ruptured blood cells in copper poisoning. Source: Dr Sandra Baxendell.
Figure 2. Copper poisoning showing (from left to right) liver, vial of bloody urine, dark kidney. Source: Dr Sandra Baxendell.
Figure 2. Copper poisoning showing (from left to right) liver, vial of bloody urine, dark kidney. Source: Dr Sandra Baxendell.

Copper Sulphate

Copper sulphate should not be used as either a drench or added to the feed or water of goats due to the risk of copper poisoning. The use of blocks containing copper to stop the growth of algae in large water containers or troughs is acceptable, but care should be taken if combined with other sources of copper.

Copper Oxide Wire Particles (COWP)

Overseas research has shown that COWP can be effective in killing barber’s pole worms (but not other types of worms) in goats, as well as lambs. COWPs have also been shown to reduce the number of barber’s pole worm eggs produced and improve the packed cell volumes of the goats’ blood.

Copper oxide wire particles are a much safer way to administer copper, but care must still be taken.

Boluses containing short sections of copper oxide wire are registered for goats, but only to correct a nutritional deficiency in copper deficient areas. Use of COWP boluses for control of barber's pole worms is an off-label use and must be prescribed by your veterinarian.

Research has shown that goats’ copper levels reduce back to normal in approximately 2–3 months after 4 grams of COWP, so it is recommended that COWP boluses are not used more than 4 times a year.

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.

Even on organic farms, goat owners have an obligation to seek veterinary attention and treatment if they have serious health issues. Treating goats that are clinically ill with worms using a treatment that has not been proven to kill these worms, does not mean that you have met your animal health and welfare obligations.