Image: Hillcrest Animal Hospital
The brown dog tick (Rhipicephalus sanguineus) is a common parasite of dogs, found the world over, with recent cases occurring across northern Australia. When ticks carrying the bacterium Ehrlichia canis, bite dogs, the dogs can develop ehrlichiosis, which typically presents as fever, lethargy, loss of appetite, unexplained weight loss or bleeding and bruising lasting between two and four weeks. Dogs can also be subclinical, meaning they are infected but show no signs, for months or even years, and can go on to develop chronic ehrlichiosis, for which signs are more severe and can be fatal.
While dogs cannot transmit E. canis to one another, ticks can become infected from dogs, creating a cycle of infection. Erhlichiosis was first detected in Australia in the Kimberly region in mid-2020 and has been found in several regions of northern Western Australia and the Northern Territory, while ticks carrying E. canis have been found in South Australia. Erhlichiosis is a nationally notifiable disease, meaning If you have a suspect case, contact your state government via the Emergency Animal Disease hotline on 1800 675 888, so that assistance with managing the case and advice on sampling requirements can be provided.
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The flystrike tools can assist you in developing a flystrike calendar that is suitable for your location and your enterprise using historic long-term weather data for your location.
Original article by Joan Burke PhD1, and Jim Miller DVM, PhD2.
1. USDA ARS, Dale Bumpers Small Farms Research Center Booneville, Arkansas
2. Louisiana State University Baton Rouge, Louisiana
Minor amendments have been made by ParaBoss to suit Australian audiences.
A key worm control strategy is to reduce the challenge or number of worms that livestock face. Aside from grazing management to clean pastures, you can kill worm larvae before they even move out onto the pasture. Nematode-trapping fungi specifically target the worm larvae after they hatch in the dung, effectively breaking the worm life cycle. In February 2021, the American Consortium for Small Ruminant Parasite Control published the fact sheet: Worm Killing Fungus, by Dr Jim Miller and Dr Joan Burke, as part of their Best Management Practices to Control Internal Parasites in Small Ruminants Fact Sheet Series.
ParaBoss has reproduced their fact sheet to highlight the role of nematode-trapping fungi as an effective biological control agent of gastrointestinal worm larvae. BioWorma® and Livamol® with BioWorma® are the only available products on the market to specifically target the worm populations on pasture.
by Deb Maxwell, ParaBoss Executive Officer
Like it or not you have chemical-resistant flies on your property right now; what you do next will likely impact how much they increase and your chemical effectiveness for years to come.
With this year's extreme flystrike challenge you may have applied chemical protection to some classes of sheep for the first time in years. More flies, more susceptible sheep, and more chemical use provide many more opportunities for a boom in chemical resistance on your property.
But you can join your fellow producers who are already putting the brakes on development of resistance in local fly populations. If you would like to maintain the current effectiveness of flystrike preventative chemicals on your property for more years, then use as many of the following strategies as you can that are relevant to your situation.
Did you know that you can treat sheep for lice and prevent flystrike at the same time? Many commercially available chemical treatments are effective against both sheep lice and blowflies, however they must be used appropriately to avoid accidentally increasing the resistance of flies and lice to these chemicals.
As products can serve both purposes, it may be appropriate to use them on numerous occasions throughout the year. Unfortunately this can also increase resistance by exposing parasites to the chemical more often, and at times where it is less effective to be targeting them.
For this reason, it is important to rotate your chemical groups between uses, to ensure you’re not using the same group two or three times in a row, with the goal being to keep resistant parasites from carrying on and multiplying.
Of course, as certain products can only be applied in particular ways, this may limit your choices when thinking about trying another. Keeping clear and accessible records of your treatments will help you to know what you’ve used before, so you know what you can use next.
Lastly, consider eradicating lice from your flock altogether. This way, you can use products solely for flystrike prevention, without worrying about the crossover with your lice treatments!
It’s important to get your drench selection right! The same basic principles to choosing drenches apply no matter whether you have sheep or goats; use the most effective drenches, use a combination of drench groups (either multiple single actives or a multi-active) where possible, and reserve persistent or long-acting drenches for specific, high worm-risk times of the year.
However, this can become tricky for goat owners, because there are far fewer products available for drenching goats, compared to the number available for use with sheep. This restricts the options available to you in seeking out the most effective drenches.
Goats also need different dose rates to sheep, so pay close attention! Any time you use a product not registered for goats, or want to modify the dose rate, you will legally need a vet’s prescription to do so. It’s also a good idea to conduct a DrenchCheck when using products that aren’t registered for goats, so you will know whether or not the product was effective.
ParaBoss News is produced with support
from Animal Health Australia