Five ways to prevent tick fever in cattle
06 October 2021
Tick fever in cattle can be extremely deadly, but there are steps producers can take to protect their herds from the disease.
Here, parasitologist and Managing Director of Dawbuts, Matt Playford, shares five things you can do to prevent it:
- reduce or maintain current tick burdens
- paddock management
- select resistant breeds
- biosecurity measures.
Weaning or branding are ideal opportunities to vaccinate calves as they rarely show vaccine reactions.
All cattle introduced from areas where ticks aren’t prominent need to be vaccinated as well, preferably 60 days prior to their first exposure to ticks, to allow for full immunity to develop.
The live vaccine produced by Queensland’s Tick Fever Centre protects against the three tick fever agents – Babesia bovis, B. bigemina and Anaplasma marginale. Note that this vaccine won’t protect against infection with Theileria, a protozoal infection which is spread by bush ticks (Haemaphysalis).
Vaccine is manufactured as fresh ready-to-use product with a 4-day shelf life. The frozen Combavac 3in1 vaccine is not available and the Tick Fever Centre will notify producers when it is being produced again.
Protection from the live vaccine is lifelong. However, a range of factors will impact vaccine efficacy and it’s a good idea to re-vaccinate very valuable animals such as bulls.
2. Reduce or maintain tick burden
The more ticks on cattle in your herd, the more likely tick fever will spread. This means that cattle with lots of ticks are more likely to be exposed to infection with tick fever.
So, should you just maintain a ‘zero tick’ policy? That’s not very easy to do and may not be the best solution.
Herds of cattle with no ticks (e.g. in the Tick-Free Zone) do not develop any immunity to tick fever. This means that they’re highly susceptible to infection when ticks do arrive e.g. in strays or bought-in cattle, or even dropped over the boundary fence. Similarly, herds of cattle inside the Tick Zone that have a high level of tick control will have low to no natural exposure to tick fever. However, having ticks doesn’t necessarily bring immunity – mainly because the tick fever organisms inside the ticks have an irregular distribution and are not found in all ticks.
The safest policy for producers in or adjoining the Tick Zone is to vaccinate all introduced stock as well as calves at three to nine months old with the tick fever vaccine, then manage the tick burdens based on the economic threshold for your herd.
3. Paddock management
Some paddocks can have very high levels of tick larvae contamination. This will include those that had large numbers of ticky cattle or those grazed by feral deer.
Knowing which paddocks have high burdens will allow producers to avoid those paddocks for susceptible cattle i.e. newly-introduced, heavily-pregnant or nutritionally-challenged stock.
Measures to decrease pasture larval burdens include spelling (up to nine months is required to clear all tick larvae), grazing with cattle treated with a ‘medium or long-acting’ product, or more intensive measures such as mowing, cropping or even burning.
4. Select resistant breeds
Brahman and other Bos indicus cattle are relatively resistant to infestations with the ticks themselves, thanks to their physical and physiological adaptations.
This resistance does vary by length of exposure to ticks and season. They are also reasonably resistant to tick fever caused by Babesia bovis and B. bigemina. However, they’re just as susceptible to Anaplasma as Bos taurus or Wagyu cattle. This means that they can still develop severe disease with tick fever.
Using tropical breeds or crossbreeding to introduce Bos indicus genes into a herd has many advantages, including adaptation to tropical conditions, but the ability to cope better with ticks and tick fever is a valuable benefit in areas of tick challenge.
5. Biosecurity measures
Bought-in cattle, strays, horses, feral deer, gates left open or even ticks that are dropped by a neighbour’s cattle at a boundary fence have all been causes of tick fever outbreaks in susceptible herds. This means that any measures you take to reduce the likelihood of tick entry will pay dividends in disease control.
Note that cattle ticks and tick fever are notifiable diseases outside of the designated Tick Zones in WA, NT and Queensland, as well as in all of NSW. Contact your vet or Biosecurity Officer if you see ticks or suspect tick fever in these areas.