Manage Ticks in Cattle

How to count cattle ticks

Sampling and or counting the ticks present on cattle provides a basis to estimate damage, monitor control methods and assess management success

Tick Counts

• Count female ticks 4.5 – 8 mm long as these will drop within 24 hours.
• Examine using fingertips/fingernails and palm of the hand to feel for lumps then part the hair and visually inspect.
• Use a counter to count all ticks on 1 side of an animal then multiply by 2.
• Primary areas to inspect are the tail butt and escutcheon.
• Secondary areas to inspect are flank, belly, dewlap, neck and ear.
• Three sites must be inspected, two primary sites and one secondary site for animals to be transported interstate or across tick free zones.

As hosts reject some ticks during feeding it is necessary to identify and count only those that will complete engorgement. The growth of parasitic ticks is characteristically slow in the early stages and then very rapid in the final 12 to 24 hours. Engorged cattle tick females, like those of many others, detach from their host overnight, or early in the morning. It has been shown that the number of engorged females detaching in the morning (Day 1) is equal to the number of females 4.5 – 8.0 mm long on the previous day (Day 0).

The pre-engorgement stages of ticks have been termed ‘standard’ ticks. Counting them provides the basis for ecological studies, estimation of damage and assessment of efficacy of control methods.

To reduce the workload and increase safety, adequate inspection facilities are required and only one side of the host need normally be counted. If an estimate of total burden is needed, the count is doubled. Due care must be taken when examining the animal for the presence of ticks. A mechanical tally counter should be used (if available) and the surface of the animal can be divided into convenient areas to examine.

Areas to examine include the tail butt (Figure 1), escutcheon (extra care needs to be taken) (Figure 2), flank (Figure 3), belly, dewlap (Figure 4) or neck (including upper neck) (Figure 5) and ear (Figure 6). An effective way to detect adult ticks, especially when they are engorging, is to feel the hair coat of the host with the palm of your hand. To find immature ticks or unfed adults, the hair can be parted systematically using both hands and eyes to find adults and nymphs (larvae will be too small to detect). Rolling the skin between your fingers can also help to make these flat life stages stand out. Visually inspect for any obvious signs of cattle tick as you approach the animal. Take note of any lumps, swellings, bumps and scabs on the skin that may need closer inspection.

Use fingertips to feel for ticks including any lumps, swellings, bumps and scabs on the skin. Remove any ticks, scabs or shells using fingernails, place in the palm of the hand for closer inspection. If the accredited certifier or person conducting the inspection normally wears glasses for reading, they should wear glasses whilst performing the inspection.

For animals to be transported interstate, or across tick free zones, an accredited certifier or inspector is required to examine three sites on a percentage of the consignment. Two primary sites (tail butt and escutcheon) and one secondary site (dewlap, ear, upper neck or flank). If a live cattle tick is found on a single animal, all animals in that consignment fail the inspection and must not be moved to the tick free zone.

In the event of finding cattle ticks on animals, or any tick of which the identity is uncertain, the owner or agent should remove the tick for positive identification. See the ‘identification’ section under professional service providers.

If you find cattle ticks on animals that are currently treated, and you suspect your treatment is failing, see the ‘resistance testing’ section under professional service providers.

The following link provides a list of accredited certifiers trained and authorised by legislation to certify the cattle tick status of livestock.

If you find cattle ticks on animals in a tick free zone, it must be reported to your relevant government department, see professional service providers.

Infestation levels – (total of one side count)

The effect of tick burden on animal performance and productivity will be higher when the animal is in poorer condition, calves are impacted more than adults, in animals with poor general health, and when feed quality or quantity are inadequate.

• 0 – 25 ticks – very low
• 25 – 50 ticks – low
• 50 – 100 ticks – low moderate
• 100 – 150 ticks – moderate
• 150 – 200 ticks – moderate to heavy
• 200 – 250 + ticks – very heavy burden (the animal will be losing condition)

Best time to count cattle ticks

Stock owners in cattle tick free and control zones in all States should monitor stock regularly to enable early detection of any cattle tick infestations. See how to count cattle tick.

Other ticks

Monitoring for economically-important native ticks, such as bush tick, paralysis tick, wallaby tick and bandicoot tick is more challenging than cattle tick as these ticks spend less time feeding on cattle (around 5 – 7 days feeding compared to cattle tick that feed for 18 – 26 days) and they also infest other native hosts as part of their life cycle. These ticks are generally found in lower numbers on cattle, but unfortunately if the tick transmits disease or toxins, low numbers can still be deadly to susceptible cattle (such as calves, animals under stress, pregnant cows and relocated naïve animals with no previous tick exposure). Finding and removing these ticks is essential and requires careful examination using both fingertips and the palm of the hand to feel for lumps. The hair is then parted and the lumps visually inspected. Pay particular attention around the head and neck. Any ticks found should be removed with fine pointed tweezers, or a tick removal device, by grasping the tick as close to the skin surface as possible and pulling upward with steady, even pressure. Avoid twisting or jerking the tick as this may break off the mouthparts.

Paralysis tick prefers temperatures around 27°C. The larvae rise in autumn with nymphs peaking in autumn to spring. Adults (the most visible stage) peak in August through December to February depending on climate. Regional differences exist as temperature and humidity determine when seasonal peaks occur; for example, adults appear earlier and peak over a longer period in the wet tropics. Figure 1 shows a summary of paralysis tick seasonal data collected over an 8-year period from NSW.

Bush tick prefer temperatures in the 10-30°C range. They avoid hot dry conditions. Occasionally other species of ticks are found on cattle (scrub tick, brown dog tick). These species may be confused with economically important species, but they are typically low in number and have little impact, so are generally not treated.

Action checklist if you find ticks

1. Identify the species of tick. Use the ParaBoss quick guide and if you remain unsure, ask your veterinarian, local Biosecurity Officer or a professional service provider for help.
2. Where is the infested animal? If the animal is outside of the cattle tick zone and you have found a cattle tick, it is a legal requirement that you notify your local Biosecurity Officer.
3. How many ticks have you found, and what part of the tick season are you in? If tick numbers are low, and you are at the end of the tick season (heading into winter or the dry season), then action may not be needed. If tick numbers are high, or you are at the start of the spring-rise, then treat your animals. Look at the when to treat cattle tick page.
4. Do you know the resistance status of your property? If chemical treatments fail to reduce tick numbers on your property then get some ticks tested to determine which chemical actives will work, and which won’t.
5. Decide if you want to eradicate or control cattle tick numbers on your property then design a management strategy that includes a program for your region and a monitoring plan.
6. If your animals need treatment the TickBoss cattle products search guide can help you to select a suitable product.
7. It is important to change chemical groups regularly to avoid an increase in acaricide resistant tick populations.
8. If your animals are showing signs of tick borne diseases (tick fever or theileriosis) or tick paralysis, monitor and remove any ticks found and seek advice from your local veterinarian or see the ParaBoss list of service providers.
9. Consider ways to reduce ticks on your property.

Eradication versus control of cattle tick

Eradication of cattle tick is possible because, as a 1-host tick, all of the host-attached life stages can be killed with planned chemical treatments. By killing ticks before they drop and lay eggs, you also stop your pastures from becoming contaminated with seed ticks. Eradication is mandatory if cattle tick are found outside of the tick zone. Check the regulatory treatment requirements for your State or Territory. In many instances tick eradication may not be not practical, or possible and therefore the next option is to manage or control tick populations to reduce business losses.

Eradication plan

To eradicate cattle tick from your property ticks must be removed from you animals, as well as seed ticks from your pastures. An eradication plan requires

• A planned program to chemical treat animals to kill ticks before they can drop and lay eggs.
• Secure boundary fences to stop infested cattle and feral animals from straying onto your property and dropping seed ticks onto the pasture.
• Treat any new animals prior to their introduction to the property.
• If pastures are highly contaminated with seed ticks consider pasture spelling or a paddock sweeper program to attract larvae off the pasture, then treat the animals before the ticks have time to mature.

Control plan

Cattle tick can be challenging to eradicate due to increasing chemical resistance, changes to land use, increased feral animal movements and limited availability of cattle dips. In instances where eradication is not possible, cattle tick monitoring and control can still be an effective means to reduce business losses.

• Monitor ticks and time treatments to keep tick numbers below a threshold level.
• Vaccinate your cattle against tick fever.
• Know your property’s acaricide resistance status so that you can select chemical actives that will work to kill ticks. Use chemical actives from different chemical groups in rotation to avoid further resistance developing.

Monitor ticks

In many instances tick eradication is not practical and therefore the next option is to manage tick populations to reduce business losses. Monitoring ticks is also important to determine if existing control methods are effective. Left unchecked, ticks cause major production and financial losses. Their direct effects include tick worry which can significantly reduce cattle live-weight gain and milk production, they can cause hide damage, and in numbers they can cause anaemia (blood loss). Ticks can also carry diseases such as tick fever (cattle tick) and theileriosis (bush tick) and the toxins of paralysis ticks can be deadly. See the tick identification section to see how to recognise cattle, bush and paralysis ticks.

When monitoring keep in mind that:

• In regions where ticks occur, they are present on farm all year.
• Cattle tick, paralysis tick and bush tick numbers all rise in spring, or with summer rains. Monitoring periods should be scheduled during these times to accurately gauge tick numbers.
• Tick numbers of all species peak over wet summers and naturally decline in winter, or with the dry season.
• Monitoring programs for ticks should include a combination of manual (using your fingertips and palm of your hand to feel for lumps) and visual inspection both in the paddock and during yarding.
• Ticks are typically found in places that are difficult for animals to lick or rub.
• For advice on tick monitoring ask your local Biosecurity Officer or regional professional service provider.

Cattle ticks

• The primary areas to search for cattle tick are the tail butt and escutcheon with secondary areas the flank, belly, dewlap, neck and ear. For more details see how to count cattle tick and best time to count cattle tick.
• Stock in cattle-tick-free and control zones should be monitored regularly to ensure early detection of any cattle tick infestations. Stock owners must monitor cattle for ticks and follow movement regulations for animals being transported across a tick free zone and or interstate.
• Larvae, unfed and male ticks are difficult to find because they are very small (less than 2mm). Fully engorged female ticks are large (>10mm) and easy to see, but the majority drop from cattle overnight, and early in the morning, to lay eggs on the pasture, so they can be missed during daytime inspections of animals. For this reason cattle tick monitoring focuses on semi-engorged female ticks 4.5 – 8 mm long. These ticks will fully engorge and drop within 24 hours.

Bush and paralysis ticks Larval ticks are attracted to carbon dioxide, this is how they find their host, so a good place to search for bush and paralysis ticks is around the face and ears. For more details see monitoring for other ticks.