Agriculture Reference
In-Depth Information
new lamb or sheep before turning it in with your own, and treat it if you fi nd
even a single ked.
Don't make the mistake of leaving any of your sheep with keds. Every
sheep must be treated in one session.
Lice
Second only to sheep keds, lice are probably the most troublesome external
parasites. One species of biting lice and several species of sucking lice affect
sheep. The eggs are attached to the individual wool fi bers and hatch into the
nymph stage 1 to 2 weeks later. After several molts, which require another
2 to 3 weeks, the nymphs emerge as adults. One interesting fact about lice is
that their most active time is often during the winter months, making them
the only pest that is active all winter.
Through feeding, lice cause intense irritation and itching, which result in
restlessness, constant scratching and rubbing against walls and fences, inter-
rupted feeding, weight loss, and severe damage to the wool. The cardinal sign
of lice in the fl ock is hundreds of telltale tags of wool hanging from fences and
trees where the sheep have been rubbing.
Lice are susceptible to the commonly used insecticides, but two treatments
are often needed to kill newly emerged nymphs, as the eggs are a protected
stage. Once removed from the sheep, they will not return unless you intro-
duce lice-infested sheep into the fl ock. If in doubt, to prevent reinfestation,
treat new animals before placing them in your fl ock.
Maggots
Maggots are the larvae of several types of fl ies known as blowfl ies. These
fl ies are about twice the size of a big housefl y, and most have distinctly shiny
bodies that are colored blue, green, or silver. They appear in the spring and
reproduce from that time through the hot weather. Flies lay their eggs at the
edges of wounds or in manure-soiled wool, and when they begin to attack,
it's called fl y-strike. The eggs hatch in 6 to 12 hours, and the maggots feed on
the live fl esh at the edge of the wound. They enlarge the wound and, if not
detected, can eventually kill an animal. Maggots often infest dog bites, so if
your sheep have been chased by dogs, check them for unnoticed wounds and
fl y-strike.
Maggots are not necessarily a serious situation — the most important
aspect of dealing with them is overcoming your own revulsion (they are
rather disgusting!). You can get rid of them quite easily if a sheep is not too
