Franklin Vets Blog

The Lowdown on Lice in Sheep & Cattle

June 29, 2017

Lice are external parasites that spend their entire life cycle on the animal. They can only spread from one animal to another by direct contact. Lice are highly host specific, which means they can only breed on their own hosts. This means that sheep lice cannot live on cattle, and cattle lice cannot live on sheep. While sheep lice can live on goats, they cannot breed on goats. The transfer of sheep lice to goats only occurs when these two species are yarded together or kept in very close proximity to one another.

Louse popultaions are highest in winter when the animal’s winter coat is dense, providing the perfect warmth for egg development to occur. When temperatures start to climb in spring and summer, temperatures within the coat become too high and egg laying stops.Sheep grazing

There are two main kinds of lice – biting and sucking lice. Sucking lice feed on the skin tissue and blood, and have mouthparts that are specifically adapted to piercing the skin. Biting lice feed on skin debris such as scabs, hair and dead skin cells, and their mouthparts are designed to help chew such food. Sheep, goats and cattle are affected by both biting and sucking lice.

Animals that are infested with lice tend to rub against everything and anything and are often seen nibbling at themselves. This constant rubbing can damage the fleece or coat over large areas of the body, resulting in visible patches of hair/wool loss and areas of raw skin. Heavy burdens can negatively impact poorly conditioned or diseased animals, cause fleece and hide damage, and can become a significant welfare concern.

Lice control is best achieved by combining animal management strategies and chemical insecticides. Treating sheep, goats and cattle in mid-autumn or early winter usually provides adequate lice control. For sheep and goats, Cypercare, a pour-on insecticide, is most effective in killing adult and juvenile biting and sucking lice. This product can be used on recently shorn and long wool breeds, and is safe to use in pregnant animals, young lambs/kids and breeding rams. Control is achieved within 4-6 weeks of treatment. For cattle, Eclipse is a great combination pour-on product. In addition to providing control against biting and sucking lice, it is also an excellent anthelmintic for internal parasite control.Cypercare

Eclipse

For more information on managing this condition or for advice on the control strategies and products available to you, please don’t hesitate to call your local Franklin Vets branch.