Article supplied by Afrivet

At least 860 tick species have been identified to date. Several of these species exist in South Africa, but many of these ticks are species specific. This means that the tick will only attach and feed on a tortoise, rhino, elephant, dog, caracal, jackal and other specific animals.

South Africa has a wide range of tick species. After the first good rains of the season, tick populations tend to explode and multiply at an incredible pace if not controlled. Tick infestations lead to diseases, sores, loss of condition and production losses in livestock.

Ticks only transmit specific diseases. The blue tick transmits gallsickness and redwater. The multi-host brown-ear tick and red-legged tick transmit theileriosis, East Coast fever and buffalo disease, and the bont tick transmits heartwater. Other ticks such as the Karoo paralysis tick, kennel tick and bontpoot tick, which causes sores and sweating sickness in particular, are of great economic importance in South Africa.

High tick loads

Strategic tick control refers to blue tick control on farms where high tick loads in late summer and autumn are causing major problems. It is important to keep in mind that normal multi-host tick control (dip/spray or pour-ons) must be combined with strategic blue tick control.

Some summer rainfall areas experienced unusually wet conditions during the previous summer and an explosion in blue tick numbers is therefore expected on many farms. The blue tick cycle carried on until late winter and numbers increased drastically after the drought.

This means that countless blue tick eggs will be present on the veld during spring. The eggs will hatch after the first spring rains and if the first generation of ticks is not controlled, it will lead to another sudden increase of blue ticks in late summer and autumn.

Figure 1: Parasite populations and number of ticks on the veld.

              

 

Early control

Strategic control during early spring is important to avoid an explosion in the blue tick population during late summer and autumn – before the first generation of adult ticks gives rise to a vast number of larvae in the second and subsequent generations.

It is very important to bear in mind that although pour-ons are extremely effective against ticks (except of course in the case of blue tick resistance), several applications of these formulations may be necessary before the animal is fully covered with the product.

The lower part of the belly in particular may be insufficiently covered by the product after the first application aimed at controlling the burden of a heavy blue tick infestation. The animal’s coat will still be thick in late winter, making it hard for pour-ons to spread.

First treatment

A combination of a macrocyclic lactone such as Ecomectin 1% Injectable and a pour-on such as Afrivet Redline is recommended for the first strategic treatment. Not only is this combination the most effective way to control blue ticks in spring, but it will also ensure sufficient control of multi-host ticks. The active ingredient in Afrivet Redline, flumethrin, causes female tick infertility and therefore helps to reduce first-generation blue tick numbers.

As soon as the farmer observes an increase in first-generation blue tick numbers, applying a combination will efficiently reduce the tick population. Keep in mind that new larvae will climb on cattle when cattle are moved to new camps. It is therefore recommended that cattle be treated again when they are moved to new camps.

It is recommended that cattle be treated monthly throughout spring, in other words three injections one month apart. Longer intervals can apply if cattle are not moved to new camps, but cattle should be treated as soon as the first adult blue ticks are observed. Normal tick control can then be employed, taking into account the number of ticks on the animals.

Be proactive and start early in the season to effectively control ticks and reduce damage.

For more information, phone Afrivet on 012 817 9060 or visit www.afrivet.co.za.