Break parasite cycle at housing

MANY cattle will be housed over the coming weeks. Coming off grass, these animals bring with them a large burden of parasites. These parasites can cause a lot of damage, reducing performance by causing diarrhoea, a drop in appetite, increasing the risk of both viral and bacterial pneumonia, and thereby affecting feed intake, reducing weight gain. If untreated, these parasites can then reinfect pastures after turnout and keep the cycle going. Housing is one of the key times to break this cycle and treat cattle against the most common internal and external parasites.

Treating parasites

There are many different options to control stomach/ intestinal worms. Ensure when choosing your product that it will cover all stages of worms, including the inhibited stomach worms. Levamisoles (yellow drenches) are only effective against adults.

Many of the combination products used to control stomach worms will also control lungworms, but be sure to check the label for efficacy against various stages of parasites and consult your vet if you are unsure.

When treating for the external parasites like lice and mange, make sure to treat on the same day as they are contagious and if treated on separate days, they will reinfect the treated animals.

Difficulty with liver fluke

Many products will only control liver fluke at the adult stage, therefore it is critical to understand the different stages of the liver fluke life-cycle. The liver fluke has three distinct stages, going from early immature to immature, followed by adult fluke.

In order to get a correct dosing strategy, it is important to use the correct product at the right time. For example, going in too early with a dose after housing will not kill early immature fluke and within a matter of weeks, they will have developed into adults.

If the flukicide used at housing is only effective against older immature and/or adult liver fluke, then dosing six to 10 weeks later is recommended to kill the early immature fluke that have now become adults. A faecal sample could help to see if fluke are present.

Delaying treatment for liver fluke until at least six weeks after housing, will ensure most of the fluke should have developed to at least the imma- ture/adult stage and will be susceptible to the treatment. The main problem with this method is that the fluke could have caused a lot of damage and loss of weight gain in the intervening period.

Dosing with a triclabendazole two to three weeks after housing should kill all