Agriculture Reference
In-Depth Information
disease called Caseous Lymphadenitis (CL). However,
lumps and bumps can be caused by a variety of other
causes.
CL is an extremely common disease of goats worldwide.
It is usually ranked by goat owners as the most important
disease they have in their herds. The disease is character-
ized by one or more abscesses involving lymph nodes.
CL is caused by Corynebacterium pseudotuberculosis.
Infection occurs by ingestion of the bacteria or by direct
contact between bacteria and skin. The bacteria can pass
through intact skin and is found in the regional lymph
nodes within 3 days of skin exposure. Abscesses most
commonly involve the lymph nodes of the head and neck.
Some goats within a herd appear to be very resistant while
others are very susceptible. Occasionally the organism will
involve internal lymph nodes and result in a wasting syn-
drome (Thin Doe Syndrome).
Clinical diagnosis is based on the characteristic
abscessation of a lymph node located usually in lymph
nodes that drain the head and neck. There is usually a herd
history of abscesses. The disease is confi rmed by culture.
Culturing abscesses is important in that there are other
bacteriologic causes of abscesses, the most important
being
Arcanobacterium pyogenes
,
Staphylococcus aureus
,
and in tropical countries
Burkholderia pseudomallei
(Meloidosis). Serologic tests are also available.
Treatment with antibiotics is rarely successful in
the treatment of this disease. Surgical drainage of
external abscesses is the treatment of choice; however, it
only treats the abscess and not the disease. It is important
to remember that all exudates from the abscess are highly
contagious and should be collected and disposed of by
burning or burying. The affected doe should be isolated
from the herd until the opened abscess is completely
healed over.
The best prevention for CL is to maintain a closed herd
or to carefully screen new additions to the herd for the
presence of abscesses or scars from old abscesses. All
affected animals should be isolated from the herd. Keyhole
feeders have a great deal of advantages in preventing fecal
oral spread of disease, however, they serve as one of the
major fomites for this disease.
There is a vaccine available for sheep through Colorado
Serum (Case-Bac) that will decrease the incidence and
severity of the disease. It is a killed vaccine that requires
two doses initially and an annual booster. The vaccine has
no effi cacy in animals that are already infected. There is a
vaccine (Glanvac) available in Canada and Australia.
Although not available in the U.S., it is apparently effec-
tive in goats.
V
ACCINE
R
EACTIONS
AND
I
NJECTION
S
ITE
A
BSCESSES
Some vaccines and many medications are highly irritating
and when injected can cause local infl ammation and swell-
ing. There may be an immediate swelling or it may take
days for the swelling to appear. Lack of sanitation and
refrigeration can result in the injection of live bacterial
contaminants into the host.
M
ISCELLANEOUS
S
WELLINGS
OF
THE
H
EAD
The following conditions cause swelling of the head:
Salivary glands cysts: Fluctuant fl uid fi lled cysts on the
jaw or head, which are fi lled with clear viscous fl uid
(saliva).
Retained cud: Cud that is trapped between the dental
arcade and the lip and is caused by problems with denti-
tion or loss of a molar.
Goiter: Swelling of the thyroid glands in response to inad-
equate levels of iodine.
Bottle jaw: Edematous swelling of the area between the
mandibles, which is caused by hypoproteinemia and
usually a result of parasitism.
Grass awn abscesses: Usually present around the lips and
cheeks and caused by thorns, briars, and grass seeds
(awns).
Hematomas and seromas: Accumulations of blood or
serum, respectively, usually associated with trauma but
may be a result of clotting disorders.
Hernias: Umbilical hernias and inguinal hernias may
occur. They contain abdominal organs and are usually
reducible.
Umbilical abscesses: Occur when the umbilicus is exposed
to moisture and bacterial contaminants. In kids that fail
to ingest colostrum, this may result in neonatal septice-
mia or “ navel ill. ”
Diseases of the Eye
Keratoconjunctivitis is infl ammation of the cornea
(keratitis) and infl ammation of the conjunctiva (conjunc-
tivitis). Keratoconjuctivitis (pinkeye) infects both the
cornea, which becomes cloudy or blue, and the mucous
membranes of the eye, which become red and cause a
discharge. If neglected, the cornea can rupture, leading to
permanent blindness. Keratoconjunctivitis can be caused
by a variety of organisms, including species of
Branhamella
,
Chlamydophila, Moraxella
, and
Mycoplasma
. The cause
should be identifi ed by culturing for the appropriate
organisms.
Treatment is with topical ophthalmic drops that must be
placed in the eye several times a day. However, it can be
