Parasites – the word itself indicates they are unwanted guests on your property. There to live off your stock, they cause nothing but trouble. At the bare minimum, they reduce live weight gain by reducing the animal’s ability to absorb nutrients. In more severe cases however, they can cause animal discomfort (itching/pain), illness and even death.
Unfortunately, parasites are everywhere so the only thing we can do is be aware of their presence, know what they do and how to get rid of them.
Parasites come in different shapes and sizes and can reside on the inside (internal) or outside (external) of an animal. The following are the most common ones:
- Worms (internal)
- Ticks (external)
- Mites (external)
- Fleas (external)
- Coccidia (internal)
- Other (eg Fluke – internal)
Luckily there are some clever drug companies who have put together drenches. Drenches come in different formats making it easy to find one that will work with your animals and your facilities. They also deal with different types of parasites – some just kill worms, others will also deal with mites etc.
When talking about drenches for livestock, the focus is often on worms. This is because worms are ubiquitous and also because they do the most damage. Young animals are especially susceptible to worms. Most species build up resistance to worms (except goats), but even then worms can still cause internal damage leading to poor performance (milk production, weight gain).
It’s vital to have a management plan in place. The simplest way is to have a drenching programme for your stock.
Simply put, there are 3 ways to drench an animal:
- Oral drench – a liquid that is injected into the mouth with a special drench gun (no needle). This is the cheapest method, however it can be quite labour intensive. The drench directly ends up in the place where it is needed without much loss of efficacy. There are also oral boluses available for selected species.
- Injectable drench – an injection under the skin that is absorbed slowly into the bloodstream. This is less effective and more costly than an oral drench, but still results in good uptake and efficacy.
- Pour-on drench – a liquid is poured onto the back of the animal in a long line over the spine. This then gets absorbed through the skin and into the bloodstream. This is the most expensive method, however it’s very easy. Some issues with this type of drench is that animals can lick it off, it takes a while to be absorbed and rain can impact on uptake.
- There are separate treatments available for external parasites like ticks and these are often used only if there is suspicion to believe animals are affected. These treatments are mainly used once as needed, but can definitely improve quality of life for the animals.
- Bear in mind, with whichever treatment you’re using, to check the withholding times before use. Often these products have a milk and/or a meat withhold so make sure they don’t interfere with your plans – alternatives might be available or your plans might need to be adapted. If a product has not been registered specifically for your species (for example, there are limited licensed products for pigs and goats), use the off label guidelines – check with your vet where you can find information on this.