Cattle keepers in several parts of the cattle corridor have turned to using crop pesticides like dudu cyper to fight ticks off their cattle. As a result, some cattle have died or gone blind.
Farmers claim that they are resorting to these crop chemicals because standard acaricides have become weak. Indeed, there is increased reports of acaricide resistance by ticks, hence the rampant break outs of livestock diseases, leading to endless quarantines.
Acaricide resistance to cattle ticks refers to the ability of ticks to overcome adverse effects of acaricides to survive. Acaricides are chemical compounds used to kill acarids which includes ticks and mites.
When resistant ticks survive an acaricide, they pass on this genetic capability to their offspring. Initially, this resistant gene is very low in a tick population. However, with continued use of the chemical, a population of resistant ticks develops. The implication of acaricide resistance is that the chemical being used becomes ineffective to kill and control cattle ticks. This reduces the number of available effective acaricides in the market.
According to Dr Stephen Birungi from Alfasan Uganda, the ‘ideal’ acaricide is one that, can be easily administered by a number of methods, such as pour-on, plunge dip, spray dip or injection, is rapidly metabolised and excreted to reduce the level of chemical residue in the animal, which requires long withholding periods and has a high level of toxicity towards all stages of the life cycle of cattle ticks.
“It should also be easily accessible by farmers,” Birungi says.
He explains that one of the reasons acaricides are abused is that they are packed in larger containers than what the average farmer may need to use.
“So what happens is that when a farmer asks for part of the acaricide, the container is opened, the farmer is given whatever quantity he asked for and then it is closed again. However, by this time, it is already compromised,” he says.
Factors that Influence the development of acaricide resistance
- Treatment frequency – the more often ticks are exposed to the chemical, the more likely they will develop resistance to it.
- Wrong dosing risks tick survival, enhancing resistance to the chemical.
- Consistent use of one chemical group for tick control.
How to reduce risk of acaricide resistance
Some basic management skills can be used to reduce the chances of acaricide resistance developing;
- Always use the recommended strength in dips as printed on the chemical label by the manufacturer.
- If using a plunge dip, always re-dip your stirrer cattle.
- Never under-dose animals during treatment with pour-on or injectable applications. Treat the mob at the rate of the heaviest animal, reducing the chance of under-dosing.
- Import only tick-free livestock on to your farm/premises. If this is unavoidable, treat livestock on arrival and only turn out tick-free cattle on to the paddock.
- If you suspect poor tick kill, notify your local area veterinary officer for investigation and testing of the acaricide.