Dosing cows as they come in for housing is essential, as when cows and cattle are indoors, it is the ideal time to treat for parasites.
The main parasites that need to be targeted are lungworms, stomach worms and liver fluke, along with external parasites, such as biting and sucking lice and mites.
Fluke and worm infections mainly occur in cattle when they are out grazing at pasture, so effective treatment at housing can therefore keep animals virtually free of worms and liver fluke until they are back out at grass in the spring.
Farmers should also be carrying out dung samples to check if your summer dosing regime and parasite control has been effective.
Cows have a level of resistance to lung and stomach worms, however, young cattle such as weanlings and young heifers do not have resistance and must be treated.
Dosing
Farmers should know what development stage the stomach or lungworm are at in order to target them appropriately and will help assess if re-dosing will be required to ensure that eggs, larvae and adult worms will be controlled.
All cattle should be treated for liver fluke at housing, as liver fluke is influenced by the climate.
There are different stages to the liver fluke cycle, with early immature fluke occurring between weeks one to five, followed by immature fluke occurring the following six to 11 weeks.
Mature fluke appears after week 12 and it is important to know what stage the fluke is at, as different products kill different stages of liver fluke.
A lot of flukicides only treat mature fluke, and so therefore, a second treatment will be required.
Products which are triclabendazole-based will kill all stages of fluke, but there has been cases where there has shown to be resistance to these products.
Sucking and biting lice and mites need to be controlled, as when cows put on their winter coat, it creates an ideal living space for theses mites and lice to spread, with symptoms being constant scratching and hair loss.
If there is a heavy infestation, a re-treatment might be needed three to four weeks later after the eggs hatch, as the treatment does not kill eggs.
Cattle can be treated with either a pour-on or spot-on product, or clear drench that contains ivermectin that can either be applied as a pour-on or down the throat.
Ensure that cattle are getting dosed relative to their weight to prevent under dosing or over dosing, as either will result in drugs being less effective.
Before applying a product, always check the withdrawal period for finishing cattle or for dairy cows.
