Agriculture Reference
In-Depth Information
Scours.
The small, brownish stomach worm,
Ostertagia,
is the main culprit
in cases of scours. This worm is so perfectly camoufl aged against the walls
of the sheep's intestine that it may be diffi cult to spot even in a postmortem
examination.
Potbelly.
Potbelly is a visible phenomenon in which an animal appears
really skinny but has a great big belly. If members of the fl ock that aren't preg-
nant appear to be, then potbelly is what you're seeing.
Wool break.
In wool, break the fl eece begins falling out at the roots or
breaks off just above the roots, making the sheep look quite motley. A few
breeds of sheep do shed their wool in the spring, and some breeds in areas of
heavy rainfall lose wool along the backbone — but if you don't happen to have
one of those breeds, all fl eeces should look solid and healthy.
Bottle jaw.
Bottle jaw is visible swelling under the jaw, and it's one of the
last symptoms to manifest — so if you see it, consider it a fi nal warning that a
sheep has worms severe enough to cause death.
Less Common Internal Parasites
The stomach worms are the most common troublemakers for sheep, but a
number of less common parasites can also cause problems.
Lungworms.
Prevalent in low-lying or wet pasture, lungworms live in air
passages and cause coughing, rapid breathing, and sometimes discharge from
the nose. The coughing can precipitate prolapse during pregnancy. The small
lungworm (hair lungworm) can cause pneumonia and bronchitis.
To prevent lungworm infestation, keep the sheep away from ponds and
wet areas where snails can be found. Several species of slugs and snails act as
intermediate hosts for the lungworms — that is, the parasite spends part of
its life cycle in another creature. This is something to consider when buying
sheep from a farm having low-lying pastures.
Tapeworms.
The feeding head of the tapeworm injures the intestine and is
thought to facilitate absorption of the toxin involved in enterotoxemia. (If you
have vaccinated against enterotoxemia, then this isn't a problem.) Tapeworms
are not usually the primary worm infestation in a sheep, but since tapeworm
segments passed in the feces are large enough to be seen in the sheep droppings,
their presence is alarming. A moderate level of tapeworm infection causes little
damage to adult animals but can seriously retard the growth of lambs.
Liver fl ukes.
Liver fl ukes require a snail or a slug to act as an intermediate
host. These hosts are found on wet, marshy land. Ponds, ditches, and swamp-
land all provide a breeding place for the snails, so fence sheep out of these
