Lice can spread quickly through a herd of cattle that have been housed for the winter as the close contact of the livestock allows populations of lice to spread with ease from one animal to another.
When left untreated, a lice outbreak in a herd causes discomfort and will have an impact on livestock performance if left untreated.
Cattle are often treated for lice at housing but a secondary outbreak can occur in the shed and farmers should monitor cattle for signs indicating the presence of lice
The following are some of the clinical signs of lice in cattle:
- Hair loss;
- Intense itching;
- Rubbing and licking;
- Inflamed skin;
- Anaemia from sucking lice, e.g. pale gums (young animals).
It is important to remember that there are two types of lice that impact cattle and some products treat one type of lice but not the other while other products will control both types of lice but not the lice eggs.
The two types of lice are:
- Biting lice: These are usually found on the head, neck, shoulders, back and rump of cattle but may spread down the sides. This louse cases extreme itching;
- Sucking lice: These have piercing mouthparts and feed on the blood and fluid of cattle.
Where farmers are concerned about lice on their cattle, it is advisable to contact their local vet to determine the best course of action for treatment.
A range of synthetic pyrethroids in spot-on or pour-on formulations are available to treat lice and these include deltamethrin and cypermethrin which will treat both biting lice and sucking lice.
Injectable macrocyclic lactones (ML’s) are available also in products such as ivermectin, eprinomectin, moxidectin, doramectin, however injectable treatments generally treat primarily sucking lice, but will also aid in the control of biting lice. Pour-on MLs will treat both sucking and biting lice.
