Cattle Lice

Cattle Lice
• Lice populations build up on cattle in the winter
months, and are mainly a problem from November
through March.
• Lice are not a problem on cattle in the summer months
because they are not able to tolerate warmer
temperatures in populations high enough to cause
noticeable symptoms.
• Cattle with lice infestations will scratch off their hair in
affected areas and lick these areas because of
• Cattle can be examined for the presence of lice in a
squeeze chute by parting the hair on the face, brisket,
shoulders, hips and tail head.
• Cattle spread lice from one another by close contact and grooming.
• If control is implemented, all the animals in the herd must be
• Ringworm and scabies may also present symptoms similar to lice
infestations, so cattlemen should check carefully before treating. If
in doubt, consult your veterinarian.
• Lice have gradual metamorphosis, which consists of eggs, nymphs
and adults.
• Lice must spend their entire life cycle on the host animal, meaning
the eggs, 3 nymphal instars, and adults are all present on the
animal at the same time.
• Lice can go from the egg stage to the adult stage in as little as 16
days, depending on the species.
• Biting Lice
– The cattle biting louse does not actually bite the
animal. Biting lice feed on organic matter on the
surface of the skin.
– Just the presence of the louse causes general
irritation which causes the animal to scratch and
• Sucking Lice
– There are three main species of sucking lice.
– These three species are the short nosed cattle louse,
the long nosed cattle louse and the little blue louse.
– All sucking lice have piercing sucking mouthparts and
pierce the skin and take blood from the animal.
– All three nymphal stages as well as the males and
females suck blood.
– Cattle appear greasy when infested with sucking lice
Detecting lice infestations
• Lice should be suspected when cattle show signs of rubbing.
• Rubbing causes hair loss on the neck, shoulders and rump and
needs to be differentiated from the normal appearance of the
seasonal shedding of the winter coat.
• To detect lice, run cattle through a chute and examine the skin by
parting the hair. Good lighting and a magnifying glass will help you
see the lice as they attempt to move away from direct sunlight.
• Biting lice of cattle are recognized by a rounded head, light brown
color and high mobility as they move when the hair is parted.
Sucking lice are grey or blue grey and have a pointed head that
tends to remain fixed to the skin. You may also see eggs, which are
white and cemented to the shafts of coat hairs in clumps.
Lice Control
– A second treatment for lice control must be made
2 to 3 weeks after the initial treatment because
the developing eggs present at the time of initial
treatment will hatch and the residual pesticide will
likely not be of a concentration high enough to kill
the newly emerging nymphs.
Sucking Cattle Lice
Severe lice infested animal.
(NC State W. Watson)
(Angus Beef Bulletin; L. Townsend Univ. of Kentucky)

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