Welcome to the Central Coast and Hunter Region Alpaca Association

At a recent Central Coast and Hunter regional AAA meeting, a member asked for information about drenches used by other alpaca breeders. This is an important issue as in Australia and New Zealand there are no anthelmintics (drenches) registered for use with alpacas. It means breeders using a drench ‘off label’ need professional advice, usually from a veterinarian. This article is based on online research and a literature review. It is for information only and not intended to replace professional advice. There is a list of members of the Australian Alpaca Veterinarians (AAV) in the back of the Australian Alpaca Industry Directory 2005-2006 for AAA members reference.

Internal parasites if untreated (or the drenches used are not effective) cause problems such as weight loss, ill thrift, anaemia, abortion and if severe enough, intestinal ulceration and death
Some internal parasites affecting alpacas are:

Round worms (nematodes) such as haemonchus (barber’s pole worm), trichostrongylus (black scour worm), ostertagia or teladorsagia (small brown stomach worm), co operia oncophora (cattle bankrupt worm)
Flat worms (cestodes) such as tapeworms (monezia) and
Flukes (trematodes) such as fasciola hepatica (liver fluke).

When choosing a drench it is important to know the difference between the drenches on the market, especially when alternating products to assist in the prevention of worm resistance. The website wormboss.com.au “Know your Drench”, developed by the Australian Sheep Industry CRC and Australian Wool Innovation, has excellent information about the drenches on the market, the worms they target and the protective period , that is, how long the treatment is active in the animal. For example, if the breeder has a large property with a quarantine or isolated paddock, they may use a broad spectrum, short acting drench for alpacas that have been purchased elsewhere. Several days after worming they would move the alpacas to a “safe” or “clean” paddock. If the breeders have a smaller property where paddock rotation is not possible, the choices are to use a drench with persistent action ( Closantel or moxidectin), or drench the alpacas more frequently as they will be continuing to ingest worm larvae as they graze. Dr Peter Rourke in his article “Alpaca Parasites” (Alpaca Hmmm, Autumn 2006) reminded breeders in the Mid North Coast area of NSW of the need to increase the frequency of drenching at “high risk times of the year (wet, hot and humid)”. He recommended drenching every 6 weeks at these times, as in this area he stated it’s almost impossible to achieve a safe pasture by spelling.

Frequent drenching can increase the risk of drench resistance, so it is useful to know which worms are developing resistance to drench groups. Stephen Love, veterinarian/State Worm Control Coordinator, Armidale, reported resistance to Closantel is widespread in northern NSW and south-eastern Queensland. Closantel is a narrow-spectrum drench used against Barber’s Pole Worm (Agnote DAI/87 revised April 2005). Kerri Tyrell of CSIRO Livestock Industries in Armidale NSW, has conducted research to address the problem of worm resistance. She developed and trialled a long-acting capsule which combined tablets of Ivermectin and Levamisole. The trial was conducted using 30 young merinos. Ivermectin alone controlled, but did not eliminate Haemonchus contortus (barber’s pole worm), however the subsequent doses of Levamisole reduced the number of eggs produced by worms 99.9 percent. It seems we cannot rely solely on one drench type to totally alleviate internal parasites.
In Agnote DAI 297, July, 2003, Stephen Love reports ‘multi-active’ or ‘combination’ products have the potential to delay the development of resistance. Combination products such as ‘Q Drench’ and ‘Genesis Xtra’ are increasingly being used by sheep owners however it must be noted that any drench with albendazole poses a risk to animals such as sheep and alpacas in the early stages of pregnancy.