Short Nosed Sucking Louse in Cattle

This is potentially the most damaging species of lice infesting cattle. In housed cattle overseas very heavy infestations can develop causing anaemia and potentially death. These lice may also cause production loss in paddocked cattle in Australia.

When in high numbers short nose sucking lice cause the coats of cattle to develop a ‘greasy’ appearance, probably because of large amounts of blood-based louse excreta in the hair.

Whereas most louse species tend to be more prevalent in young stock than old stock, short nose sucking lice tend to reach highest numbers on older animals. They have been observed to survive during summer in protected locations inside and around the ears of cattle.

Type

Sucking louse, fine mouthparts puncture the skin to feed on cattle blood.

Adults

These lice are generally about 3 mm in length and the adults often appear blue-black in colour. They have a shorter more compact head and body than the long nosed sucking louse and the ‘nose’ is bluntly rounded at the front (Figure 1). They are found in clusters and a close search must be made of a number of areas on the skin before you can gauge how severe the infestation is.

Eggs

The eggs are about 1 mm in length and colour can vary from opaque white to brownish white or even brown.

Location on animal

Adults are usually most numerous on the head and may be visible feeding around the ears, eyes and nostrils. In heavier infestations, they spread more widely over the body, commonly in clusters along the top of the head and neck, at the base of the horns, and around the nostrils and eyes. In some instances they are found in the hair of the tail switch.

Life cycle

The incubation period of the eggs of this species is 11-18 days and the complete life cycle from egg to adult takes 20-40 days depending on temperature, but is usually about 30 days. Females live 15 or 16 days, producing one or two eggs per day.

Control