Cattle production: Dipping to control East Coast fever (part 1)

dipping

Dipping, or acaricides, is one of the weapons in farmers’ arsenal in the war against East Coast fever (ECF).

There are three major options available in the battle against ECF:
dipping to control the ticks,
vaccinating to control the parasitic protozoan parasites that cause the disease,
treating animals soon after they have been infected to save them.

One size definitely does not fit all and scientists, vets and farmers seem to agree that all 3 options must be combined for the best possible outcome.

DIPPING TO CONTROL ECF

Dipping as a single approach to getting ECF under control is highly problematic.

However, the use of acaricides (dips) is routine in the fight against ticks and since it is the ticks that transmit ECF to cattle, killing them is part of the management and control of ECF.

Also read: The basic principles of tick control

ERADICATION

In South Africa (SA) the State Veterinary Department eradicated Theileria parva (the parasite that causes ECF) in 1954 after a long and massive campaign.

Tight vet controls were implemented country-wide. Animals were quarantined, until cleared of ECF, exposed animals were slaughtered and cattle were dipped every 5 days.

SA’s seasons are well defined, so there would have been one generation of ticks a year which is easier than dealing with 3, possibly overlapping, generations of ticks – all at different stages of the life cycle.

The likelihood of such a campaign being successfully carried out in central, eastern and other parts of southern Africa is nil.

COSTS

Dip is expensive, varying between US$6 and US$36 per adult animal, and individual small-scale farmers cannot afford to dip their cattle at regular, recommended intervals. (This is where you tap into the power of your farmer group.)

For now, small-scale farmers are largely dependent on their governments to subsidise dipping programmes, but state-run and funded dipping programmes in Africa have mostly failed or are in the process of failing.

GROWING POPULATIONS OF RESISTANT TICKS

Tick resistance to acaricides is another problem, but one can’t throw out the baby with the bathwater, and resistance tends to be area specific rather than sub-region specific.

Farmers need to know what dip works locally so that they limit further resistance to acaricide products.

One way to take responsible action is to switch acaricides from time to time, so as not to give resistant ticks a gap. Stock farmers know very well where the disease threat is greater and naturally tend to keep their cattle out of these areas, moving on to safer grazing.

Of course, if any of the cattle are ECF carriers or actively infected, this practice can lead to expansion of the tick’s range and therefore the range of ECF. Think hard about this when moving your cattle or allowing cattle from other areas to come into or through your grazing.

ENVIRONMENT

Dipping comes with concerns about the environment, especially chemical contamination of rivers, streams and wetlands – systems on which every farmer depends.

In some countries there are restrictions on organophosphate dips because of the toxic effects organophosphate has on mammals, birds and fish, despite its quick elimination from the environment.

RESIDUES

Unacceptable residue levels (acaricide chemicals that remain in milk and in meat) is another potential problem that can have a direct effect on small-, medium- and large-scale farmers.

South African ostrich and game farmers suffered a blow only last month when European Union inspectors banned their products for export because they found the state vet department had failed to properly monitor drug, and pesticide, residues in game and ostrich meat.

Next: More on how dips work (including product names)

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