Agriculture Reference
In-Depth Information
Ovine Progressive Pneumonia
Any disease can cause chronically thin sheep, but if nutritional defi ciencies
and parasites have been eliminated as a reason, the next most likely cause is
ovine progressive pneumonia (OPP), a slow virus that is similar to AIDS in
humans and which takes at least 2 years to manifest its signs. The virus slowly
causes progressive lung damage. Ewes gradually lose stamina and body condi-
tion and have serious breathing problems, ending in physical weakness and
fatal pneumonia.
While there is currently no cure for or vaccine against OPP, there are new
tests that make disease control possible. To avoid OPP, all breeding animals
must be tested annually, and infected animals must be eliminated. Be sure to
purchase only OPP-free breeding-stock replacements. Because OPP is trans-
mitted from ewe to lamb primarily through milk, a valuable pregnant ewe that
has OPP should be isolated from the fl ock, with her lamb taken immediately at
birth and raised on colostrum replacer and lamb milk replacer. This is almost
100 percent effective in preventing OPP in the offspring of these ewes.
Any animals that test positive for OPP should at a minimum be isolated
from the rest of the fl ock, because the disease can be transmitted from infected
animals via respiratory secretions when animals are confi ned to crowded
quarters, but really the best way to protect your fl ock is to cull the animals
that test positive. All sheep that test positive do not necessarily come down
with the disease; however, once signs appear, the disease is invariably fatal.
Ovine progressive pneumonia is another example of a “purchased disease”
and certainly underlines the need to be extremely careful when buying the
initial fl ock and any replacement animals. Animals being considered for pur-
chase should be tested before introducing them into the fl ock to protect your
sheep from disease. Request proof that the fl ock has been tested for OPP.
There is a group dedicated to raising awareness of OPP: the OPP Con-
cerned Sheep Breeders Society is a resource for shepherds concerned about
OPP. This group provides a network for shepherds who are working to eradi-
cate or control this insidious disease. (See Resources.)
Soremouth
Soremouth, the scientifi c word for which is
ecthyma,
is caused by a contagious
virus that can be transmitted fairly easily from sheep to humans. If soremouth
is suspected, wear gloves while handling your sheep. The symptoms start with
pustules and scabs on the mucous membranes — including lips, eyes, and
teats — and the feet.
