Agriculture Reference
In-Depth Information
become pregnant to handle does or kids during
delivery.
to stress-induced abortion (nutritional, behavioral, or
hypothermic).
Excessive caloric intake causes fat does that have dif-
fi culty delivering (dystocia); conversely too little nutrition
for the late pregnant doe can result in a skinny doe that
gives birth to weak kids that fail to survive. Defi ciencies
of selenium, copper, iodine, calcium, and vitamin A may
causes problems and defects that result in abortions, still-
birth, or neonatal deaths.
A small pelvic diameter may be either genetic or
developmental. If such does are mated to bucks that
produce high birth-weight kids, dystocia and mortality
could result.
There is ample scientifi c evidence that poor mothering
is partly genetic in sheep, the same is probably true in
goats. Factors that disturb bonding between does and kids
can also cause postnatal mortality. These factors include a
high stocking rate, frequent stock movement, and any type
of disturbance. Weather can cause large-scale deaths in
newborn kids. The combination of low temperatures,
wind, and rain is collectively known as the chill factor.
Finally, kids will die if they cannot consume enough milk.
Damaged teats or udders (mastitis) must be identifi ed
before kidding. Pendulous udders and teats get progres-
sively larger as the doe ages. Does must get enough feed
to allow for good udder development and milk supply.
The diagnosis of the type and cause of prenatal mortality
is complex and best performed by a skilled veterinarian
and a competent diagnostic laboratory.
Metritis (infection of the uterus) may be part of the
picture seen with neonatal mortality and thus will form part
of the control measures required. However, there is a par-
ticular infection seen in does that kid in unhygienic condi-
tions. It is known as uterine gangrene and is caused by
infection with clostridial organisms like
C. septicum.
,
C. novyi
, and
C. chauvoei
. Multiple births make infection
more likely. Treatment with penicillin must be prompt to
be successful, and vaccination may be necessary if kidding
conditions cannot be improved.
In bucks or wethers, infection of the prepuce by
Corynebacterium renale
as a consequence of excessive
urea in urine will result in painful urination and may result
in bucks being unwilling to mate. This disease is known
as balanoposthitis, or pizzle rot, and is best prevented by
lowering dietary protein intake.
Epididymitis in goats is caused mainly by
Brucella meli-
tensis
, but not
B. ovis
, which is confi ned to sheep only.
Epididymitis may also occur as a result of infection by
organisms like species of
Hemophilus
,
Pasturella
,
Actinobacillus
, and
Corynebacterium
. Diagnosis is made
In the U.S., the most common cause of infectious abor-
tion is toxoplasmosis caused by
Toxoplasma gondii
, a pro-
tozoan parasite. Toxoplasma will cause fetal infection
throughout pregnancy with fetal resorption or mummifi ca-
tion if infection occurs in the fi rst trimester. Abortion,
stillbirths, or the birth of weak kids result from infection
later in pregnancy. Diagnosis is made by demonstrating
the presence of the organism. There are no drugs that
effectively treat this organism. Goats that become infected
are infected for life. Prevention is by limiting exposure of
goats to cat feces, particularly young cats and pregnant
goats. A vaccine is available in the U.K.
The second most common infectious cause of abortion
in the U.S. is enzootic abortion caused by
Chlamydiophilus
abortus
, which is an intracellular organism containing both
RNA and DNA. It will cause abortion at any time during
pregnancy of goats. The doe usually remains healthy.
Diagnosis is based on identifying the organism on the
placenta or fetus. Treatment is with antibiotics. Tetracycline
is generally the drug of choice although resistance has been
reported. Prevention is by vaccination of doelings prior to
breeding and annual prebreeding boosters to does. In the
face of an abortion storm, administration of tetracycline in
the feed or by injection may prevent abortions.
Miscellaneous infectious causes of abortion include
a number of bacterial diseases such as a
Listeriosis
,
Salmonellosis
,
Leptospirosis
,
Campylobacter
,
Brucella
abortus
, and
Brucella melitensis
. The last named disease
is a big problem in goats in many countries, and easily
transmits to humans, where it is called malta fever. In
goats, it causes abortion storms and chronic (long-term)
mastitis, and milk is the main source of infection for goat
kids and humans. Pasteurization is thus usually deemed
essential. There is no treatment, but there are good vac-
cines available.
The rickettsial organism
Coxiella burnetii
causes Q
fever in humans and abortions in goats. Another rickettsia
(
Cytoecetes phagocytophilia
) causes tick - borne fever,
which results in abortion in goats. Viral causes of abortions
and perinatal death include border disease (Pestivirus) and
Rift Valley fever (Bunyavirus). Any severe disease,
particularly those causing fever and anorexia, may result
indirectly in abortions in goats.
Nutritional causes of abortions are important in goats.
An energy defi ciency in late pregnancy can cause an abor-
tion storm, particularly in young does and those carrying
multiple fetuses. Angora goats are particularly susceptible
