Cattle Tick (Rhipicephalus microplus)
The cattle tick is the most serious external parasite of cattle in Australia. It is widespread in many areas of the Northern Territory, Queensland and a small area of northeast NSW but large parts of northern Australia have low or no tick populations and these areas are protected by stock movement regulations.
Cattle tick is primarily a parasite of cattle, however buffalo, deer, camels, horses and sheep can also act as hosts for the cattle tick. Ticks have also been seen on donkeys, goats, dogs and pigs.
Cattle ticks are usually found in the areas of the base of the tail, escutcheon, belly, shoulder, dewlap and ears. However, when an animal is heavily infested, they occur anywhere on the body.
Ticks and disease
Tick infestation leads to ‘tick worry’ and loss of blood, both of which will lead to loss of animal condition and a decreased rate of production. Heavy infestations can kill calves and, sometimes, adult animals (especially if in poor condition). Cattle do develop a degree of resistance to cattle tick and as their resistance develops, the tick numbers they carry decreases. Bos indicus cattle (tropical breeds) and their crosses develop greater tick resistance than do Bos tauruscattle (British and European breeds).
Cattle tick is also responsible for transmitting three blood-borne tick fever organisms, Babesia bovis, B. bigemina and Anaplasma marginale, which cause 'Tick Fever'. Tick fever results in sickness and death in cattle.
A further production loss is the damage that tick bites cause to the hides of infested animals. This hide damage reduces the value of the hides.
When and where are ticks a problem?
Cattle ticks can be seen year round. However, in most areas they are a significant problem from late spring to mid-winter, with a peak period in late summer and autumn. It is important for stock owners to be checking their livestock for ticks at this time.
In Australia, the distribution of cattle tick is limited by legislated movement controls of cattle and other susceptible species. The tick infected zone comprises the coastal area east of the Great Dividing Range and north of the Great Northern Rail line in Queensland. Cattle ticks are also found in the northern areas of Western Australia and the Northern Territory. Cattle ticks occur sporadically through the northern rivers area of New South Wales. In these states and territory, there are legislated movement controls in place to prevent the movement of cattle ticks to the south of the 'Tick Line'.
Cattle tick outbreaks can and do occur in the tick free zones from inappropriate cattle movement. Outbreaks are more common in the marginal areas adjacent to the infected zone.
Control of Cattle Tick
A regulated tick control strategy is managed by state governments throughout Australia. Cattle tick control is aimed at preventing the 'spring rise' by commencing a strategic treatment program in the late autumn and early spring.
Cattle ticks can be controlled to varying degrees using tick-resistant cattle, particularly Bos indicus breeds which have a degree of natural immunity, strategic treatments with chemicals, use of a cattle tick vaccine, pasture spelling or combinations of these methods.
NSW or Victorian producers wishing to use tick fever vaccine must first obtain approval from their local Department of Primary Industries (DPI) office. Producers from other states do not require approval and can obtain the vaccine through their veterinarian or the Tick Fever Centre, Queensland. Cattle of any age can be vaccinated, but it is best to vaccinate animals at 3-9 months of age when there is little risk of reactions to the vaccine.
Other control measures include maintaining fences in good order to prevent livestock from straying, ensure any livestock entering your property are tick-free and, if livestock is brought in from Queensland, ensure they stop at the border for inspection and treatment. This apples to cattle, horses and other livestock.
Cattle ticks are a notifiable disease in NSW which means stock owners are required by law to inform the authorities of any findings on their stock.
Stock owners are urged to check their cattle and report any signs of ticks so control measures can be taken. If an infestation is managed early, the ticks are easier to eradicate from the affected property and the risk of ticks multiplying and spreading to other properties is reduced.
Before entering tick free or control zones, stock from the tick infected zone must be inspected clean and treated. Contact your relevant state government animal health officers for more details of movement restrictions and the necessary legislated treatments that must be undertaken.
If you are intending to cross the New South Wales-Queensland border with horses, cattle or other livestock or if you find cattle tick outside of the cattle tick infested zone, contact Biosecurity Queensland on 07 3404 6999.
Image © The State of Queensland (Department of Agriculture, Fisheries and Forestry) 2010-2014