Division of Agricultural Sciences and Natural Resources • Oklahoma State University
Oklahoma Cooperative Extension Fact Sheets
are also available on our website at:
Oklahoma Cooperative Extension Service
Department of Entomology and Plant Pathology
Dave Sparks D.V.M.
Area Extension Food Animal Quality and Health Specialist
Arthropod pests limit production in the goat industry in
many ways. External parasites feed on body tissue such as
blood, skin, and hair. The wounds and skin irritation produced
by these parasites result in discomfort and irritation to the
animal. Parasites can transmit diseases from sick to healthy
animals. They can reduce weight gain and milk production.
In general, infested livestock cannot be efficiently managed.
Lice (Order: Phthiraptera) are wingless, dorsally flattened,
permanent ectoparasites of birds and mammals. More than
3,000 species have been described, mainly parasites of birds.
Lice infest a wide range of domestic livestock, including pigs,
cattle, goats, and sheep, and cause a chronic dermatitis (pe-
diculosis), characterized by constant irritation, itching, rubbing,
and biting of the hair or fleece. Goat lice are host specific and
only attack goats and their close relatives such as sheep.
Lice are divided into two main groups: the Anoplura (suck-
ing lice) and Mallophaga (chewing or biting lice). Biting lice
have chewing mouthparts and feed on particles of hair, scab
and skin exudations. Sucking lice pierce the host’s skin and
draw blood. Louse-infested animals may be recognized by
their dull, matted coat or excessive scratching and grooming
behavior. The irritation from louse feeding causes animals to
rub and scratch, causing raw areas on the skin or loss of hair.
Weight loss may occur as a result of nervousness and improper
nutrition. Milk production is reduced up to 25 percent. Also,
the host is often listless, and in severe cases, loss of blood
to sucking lice can lead to a